Add the const qualifier to all the ctl_tables in the tree except for
watchdog_hardlockup_sysctl, memory_allocation_profiling_sysctls,
loadpin_sysctl_table and the ones calling register_net_sysctl (./net,
drivers/inifiniband dirs). These are special cases as they use a
registration function with a non-const qualified ctl_table argument or
modify the arrays before passing them on to the registration function.
Constifying ctl_table structs will prevent the modification of
proc_handler function pointers as the arrays would reside in .rodata.
This is made possible after commit 78eb4ea25c ("sysctl: treewide:
constify the ctl_table argument of proc_handlers") constified all the
proc_handlers.
Created this by running an spatch followed by a sed command:
Spatch:
virtual patch
@
depends on !(file in "net")
disable optional_qualifier
@
identifier table_name != {
watchdog_hardlockup_sysctl,
iwcm_ctl_table,
ucma_ctl_table,
memory_allocation_profiling_sysctls,
loadpin_sysctl_table
};
@@
+ const
struct ctl_table table_name [] = { ... };
sed:
sed --in-place \
-e "s/struct ctl_table .table = &uts_kern/const struct ctl_table *table = \&uts_kern/" \
kernel/utsname_sysctl.c
Reviewed-by: Song Liu <song@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> # for kernel/trace/
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> # SCSI
Reviewed-by: Darrick J. Wong <djwong@kernel.org> # xfs
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Corey Minyard <cminyard@mvista.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Bill O'Donnell <bodonnel@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Acked-by: Anna Schumaker <anna.schumaker@oracle.com>
Signed-off-by: Joel Granados <joel.granados@kernel.org>
indivudual patches which are described in their changelogs.
- "Allocate and free frozen pages" from Matthew Wilcox reorganizes the
page allocator so we end up with the ability to allocate and free
zero-refcount pages. So that callers (ie, slab) can avoid a refcount
inc & dec.
- "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to use
large folios other than PMD-sized ones.
- "Fix mm/rodata_test" from Petr Tesarik performs some maintenance and
fixes for this small built-in kernel selftest.
- "mas_anode_descend() related cleanup" from Wei Yang tidies up part of
the mapletree code.
- "mm: fix format issues and param types" from Keren Sun implements a
few minor code cleanups.
- "simplify split calculation" from Wei Yang provides a few fixes and a
test for the mapletree code.
- "mm/vma: make more mmap logic userland testable" from Lorenzo Stoakes
continues the work of moving vma-related code into the (relatively) new
mm/vma.c.
- "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David
Hildenbrand cleans up and rationalizes handling of gfp flags in the page
allocator.
- "readahead: Reintroduce fix for improper RA window sizing" from Jan
Kara is a second attempt at fixing a readahead window sizing issue. It
should reduce the amount of unnecessary reading.
- "synchronously scan and reclaim empty user PTE pages" from Qi Zheng
addresses an issue where "huge" amounts of pte pagetables are
accumulated
(https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/).
Qi's series addresses this windup by synchronously freeing PTE memory
within the context of madvise(MADV_DONTNEED).
- "selftest/mm: Remove warnings found by adding compiler flags" from
Muhammad Usama Anjum fixes some build warnings in the selftests code
when optional compiler warnings are enabled.
- "mm: don't use __GFP_HARDWALL when migrating remote pages" from David
Hildenbrand tightens the allocator's observance of __GFP_HARDWALL.
- "pkeys kselftests improvements" from Kevin Brodsky implements various
fixes and cleanups in the MM selftests code, mainly pertaining to the
pkeys tests.
- "mm/damon: add sample modules" from SeongJae Park enhances DAMON to
estimate application working set size.
- "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn
provides some cleanups to memcg's hugetlb charging logic.
- "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song
removes the global swap cgroup lock. A speedup of 10% for a tmpfs-based
kernel build was demonstrated.
- "zram: split page type read/write handling" from Sergey Senozhatsky
has several fixes and cleaups for zram in the area of zram_write_page().
A watchdog softlockup warning was eliminated.
- "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin Brodsky
cleans up the pagetable destructor implementations. A rare
use-after-free race is fixed.
- "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes
simplifies and cleans up the debugging code in the VMA merging logic.
- "Account page tables at all levels" from Kevin Brodsky cleans up and
regularizes the pagetable ctor/dtor handling. This results in
improvements in accounting accuracy.
- "mm/damon: replace most damon_callback usages in sysfs with new core
functions" from SeongJae Park cleans up and generalizes DAMON's sysfs
file interface logic.
- "mm/damon: enable page level properties based monitoring" from
SeongJae Park increases the amount of information which is presented in
response to DAMOS actions.
- "mm/damon: remove DAMON debugfs interface" from SeongJae Park removes
DAMON's long-deprecated debugfs interfaces. Thus the migration to sysfs
is completed.
- "mm/hugetlb: Refactor hugetlb allocation resv accounting" from Peter
Xu cleans up and generalizes the hugetlb reservation accounting.
- "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino
removes a never-used feature of the alloc_pages_bulk() interface.
- "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park
extends DAMOS filters to support not only exclusion (rejecting), but
also inclusion (allowing) behavior.
- "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi
"introduces a new memory descriptor for zswap.zpool that currently
overlaps with struct page for now. This is part of the effort to reduce
the size of struct page and to enable dynamic allocation of memory
descriptors."
- "mm, swap: rework of swap allocator locks" from Kairui Song redoes and
simplifies the swap allocator locking. A speedup of 400% was
demonstrated for one workload. As was a 35% reduction for kernel build
time with swap-on-zram.
- "mm: update mips to use do_mmap(), make mmap_region() internal" from
Lorenzo Stoakes reworks MIPS's use of mmap_region() so that
mmap_region() can be made MM-internal.
- "mm/mglru: performance optimizations" from Yu Zhao fixes a few MGLRU
regressions and otherwise improves MGLRU performance.
- "Docs/mm/damon: add tuning guide and misc updates" from SeongJae Park
updates DAMON documentation.
- "Cleanup for memfd_create()" from Isaac Manjarres does that thing.
- "mm: hugetlb+THP folio and migration cleanups" from David Hildenbrand
provides various cleanups in the areas of hugetlb folios, THP folios and
migration.
- "Uncached buffered IO" from Jens Axboe implements the new
RWF_DONTCACHE flag which provides synchronous dropbehind for pagecache
reading and writing. To permite userspace to address issues with
massive buildup of useless pagecache when reading/writing fast devices.
- "selftests/mm: virtual_address_range: Reduce memory" from Thomas
Weißschuh fixes and optimizes some of the MM selftests.
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Merge tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
"The various patchsets are summarized below. Plus of course many
indivudual patches which are described in their changelogs.
- "Allocate and free frozen pages" from Matthew Wilcox reorganizes
the page allocator so we end up with the ability to allocate and
free zero-refcount pages. So that callers (ie, slab) can avoid a
refcount inc & dec
- "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to
use large folios other than PMD-sized ones
- "Fix mm/rodata_test" from Petr Tesarik performs some maintenance
and fixes for this small built-in kernel selftest
- "mas_anode_descend() related cleanup" from Wei Yang tidies up part
of the mapletree code
- "mm: fix format issues and param types" from Keren Sun implements a
few minor code cleanups
- "simplify split calculation" from Wei Yang provides a few fixes and
a test for the mapletree code
- "mm/vma: make more mmap logic userland testable" from Lorenzo
Stoakes continues the work of moving vma-related code into the
(relatively) new mm/vma.c
- "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David
Hildenbrand cleans up and rationalizes handling of gfp flags in the
page allocator
- "readahead: Reintroduce fix for improper RA window sizing" from Jan
Kara is a second attempt at fixing a readahead window sizing issue.
It should reduce the amount of unnecessary reading
- "synchronously scan and reclaim empty user PTE pages" from Qi Zheng
addresses an issue where "huge" amounts of pte pagetables are
accumulated:
https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/
Qi's series addresses this windup by synchronously freeing PTE
memory within the context of madvise(MADV_DONTNEED)
- "selftest/mm: Remove warnings found by adding compiler flags" from
Muhammad Usama Anjum fixes some build warnings in the selftests
code when optional compiler warnings are enabled
- "mm: don't use __GFP_HARDWALL when migrating remote pages" from
David Hildenbrand tightens the allocator's observance of
__GFP_HARDWALL
- "pkeys kselftests improvements" from Kevin Brodsky implements
various fixes and cleanups in the MM selftests code, mainly
pertaining to the pkeys tests
- "mm/damon: add sample modules" from SeongJae Park enhances DAMON to
estimate application working set size
- "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn
provides some cleanups to memcg's hugetlb charging logic
- "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song
removes the global swap cgroup lock. A speedup of 10% for a
tmpfs-based kernel build was demonstrated
- "zram: split page type read/write handling" from Sergey Senozhatsky
has several fixes and cleaups for zram in the area of
zram_write_page(). A watchdog softlockup warning was eliminated
- "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin
Brodsky cleans up the pagetable destructor implementations. A rare
use-after-free race is fixed
- "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes
simplifies and cleans up the debugging code in the VMA merging
logic
- "Account page tables at all levels" from Kevin Brodsky cleans up
and regularizes the pagetable ctor/dtor handling. This results in
improvements in accounting accuracy
- "mm/damon: replace most damon_callback usages in sysfs with new
core functions" from SeongJae Park cleans up and generalizes
DAMON's sysfs file interface logic
- "mm/damon: enable page level properties based monitoring" from
SeongJae Park increases the amount of information which is
presented in response to DAMOS actions
- "mm/damon: remove DAMON debugfs interface" from SeongJae Park
removes DAMON's long-deprecated debugfs interfaces. Thus the
migration to sysfs is completed
- "mm/hugetlb: Refactor hugetlb allocation resv accounting" from
Peter Xu cleans up and generalizes the hugetlb reservation
accounting
- "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino
removes a never-used feature of the alloc_pages_bulk() interface
- "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park
extends DAMOS filters to support not only exclusion (rejecting),
but also inclusion (allowing) behavior
- "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi
introduces a new memory descriptor for zswap.zpool that currently
overlaps with struct page for now. This is part of the effort to
reduce the size of struct page and to enable dynamic allocation of
memory descriptors
- "mm, swap: rework of swap allocator locks" from Kairui Song redoes
and simplifies the swap allocator locking. A speedup of 400% was
demonstrated for one workload. As was a 35% reduction for kernel
build time with swap-on-zram
- "mm: update mips to use do_mmap(), make mmap_region() internal"
from Lorenzo Stoakes reworks MIPS's use of mmap_region() so that
mmap_region() can be made MM-internal
- "mm/mglru: performance optimizations" from Yu Zhao fixes a few
MGLRU regressions and otherwise improves MGLRU performance
- "Docs/mm/damon: add tuning guide and misc updates" from SeongJae
Park updates DAMON documentation
- "Cleanup for memfd_create()" from Isaac Manjarres does that thing
- "mm: hugetlb+THP folio and migration cleanups" from David
Hildenbrand provides various cleanups in the areas of hugetlb
folios, THP folios and migration
- "Uncached buffered IO" from Jens Axboe implements the new
RWF_DONTCACHE flag which provides synchronous dropbehind for
pagecache reading and writing. To permite userspace to address
issues with massive buildup of useless pagecache when
reading/writing fast devices
- "selftests/mm: virtual_address_range: Reduce memory" from Thomas
Weißschuh fixes and optimizes some of the MM selftests"
* tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits)
mm/compaction: fix UBSAN shift-out-of-bounds warning
s390/mm: add missing ctor/dtor on page table upgrade
kasan: sw_tags: use str_on_off() helper in kasan_init_sw_tags()
tools: add VM_WARN_ON_VMG definition
mm/damon/core: use str_high_low() helper in damos_wmark_wait_us()
seqlock: add missing parameter documentation for raw_seqcount_try_begin()
mm/page-writeback: consolidate wb_thresh bumping logic into __wb_calc_thresh
mm/page_alloc: remove the incorrect and misleading comment
zram: remove zcomp_stream_put() from write_incompressible_page()
mm: separate move/undo parts from migrate_pages_batch()
mm/kfence: use str_write_read() helper in get_access_type()
selftests/mm/mkdirty: fix memory leak in test_uffdio_copy()
kasan: hw_tags: Use str_on_off() helper in kasan_init_hw_tags()
selftests/mm: virtual_address_range: avoid reading from VM_IO mappings
selftests/mm: vm_util: split up /proc/self/smaps parsing
selftests/mm: virtual_address_range: unmap chunks after validation
selftests/mm: virtual_address_range: mmap() without PROT_WRITE
selftests/memfd/memfd_test: fix possible NULL pointer dereference
mm: add FGP_DONTCACHE folio creation flag
mm: call filemap_fdatawrite_range_kick() after IOCB_DONTCACHE issue
...
The comment removed in this patch originally belonged to the
build_zonelists_in_zone_order() function, which was introduced by commit
f0c0b2b808 ("change zonelist order: zonelist order selection logic").
Later, commit c9bff3eebc ("mm, page_alloc: rip out ZONELIST_ORDER_ZONE")
removed build_zonelists_in_zone_order() but left its comment behind.
Subsequently, commit 9d3be21bf9 ("mm, page_alloc: simplify zonelist
initialization") moved the node_order variable into build_zonelists(),
making the comment originally belonged to build_zonelists_in_zone_order()
appear as if it were part of build_zonelists().
Remove this misleading comment.
Link: https://lkml.kernel.org/r/20250115041634.63387-1-yuntao.wang@linux.dev
Signed-off-by: Yuntao Wang <yuntao.wang@linux.dev>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm: alloc_pages_bulk: small API refactor", v2.
Today, alloc_pages_bulk_noprof() supports two arguments to return
allocated pages: a linked list and an array. There are also higher level
APIs for both.
However, the linked list API has apparently never been used. So, this
series removes it along with the list API and also refactors the remaining
API naming for consistency.
This patch (of 2):
commit 387ba26fb1 ("mm/page_alloc: add a bulk page allocator") added
__alloc_pages_bulk() along with the page_list argument. The next commit
0f87d9d30f ("mm/page_alloc: add an array-based interface to the bulk
page allocator") added the array-based argument. As it turns out, the
page_list argument has no users in the current tree (if it ever had any).
Dropping it allows for a slight simplification and eliminates some
unnecessary checks, now that page_array is required.
Also, note that the removal of the page_list argument was proposed before
in the thread below, where Matthew Wilcox mentions that:
"""
Iterating a linked list is _expensive_. It is about 10x quicker to
iterate an array than a linked list.
"""
(https://lore.kernel.org/linux-mm/20231025093254.xvomlctwhcuerzky@techsingularity.net)
Link: https://lkml.kernel.org/r/cover.1734991165.git.luizcap@redhat.com
Link: https://lkml.kernel.org/r/f1c75db91d08cafd211eca6a3b199b629d4ffe16.1734991165.git.luizcap@redhat.com
Signed-off-by: Luiz Capitulino <luizcap@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
My machine has 4 NUMA nodes, each equipped with 32GB of memory. I have
configured each NUMA node with 16GB of CMA and 16GB of in-use hugetlb
pages. The allocation of contiguous memory via cma_alloc() can fail
probabilistically.
When there are free hugetlb folios in the hugetlb pool, during the
migration of in-use hugetlb folios, new folios are allocated from the free
hugetlb pool. After the migration is completed, the old folios are
released back to the free hugetlb pool instead of being returned to the
buddy system. This can cause test_pages_isolated() check to fail,
ultimately leading to the failure of cma_alloc().
Call trace:
cma_alloc()
__alloc_contig_migrate_range() // migrate in-use hugepage
test_pages_isolated()
__test_page_isolated_in_pageblock()
PageBuddy(page) // check if the page is in buddy
To address this issue, we introduce a function named
replace_free_hugepage_folios(). This function will replace the hugepage
in the free hugepage pool with a new one and release the old one to the
buddy system. After the migration of in-use hugetlb pages is completed,
we will invoke replace_free_hugepage_folios() to ensure that these
hugepages are properly released to the buddy system. Following this step,
when test_pages_isolated() is executed for inspection, it will
successfully pass.
Additionally, when alloc_contig_range() is used to migrate multiple in-use
hugetlb pages, it can result in some in-use hugetlb pages being released
back to the free hugetlb pool and subsequently being reallocated and used
again. For example:
[huge 0] [huge 1]
To migrate huge 0, we obtain huge x from the pool. After the migration is
completed, we return the now-freed huge 0 back to the pool. When it's
time to migrate huge 1, we can simply reuse the now-freed huge 0 from the
pool. As a result, when replace_free_hugepage_folios() is executed, it
cannot release huge 0 back to the buddy system. To address this issue, we
should prevent the reuse of isolated free hugepages during the migration
process.
Link: https://lkml.kernel.org/r/1734503588-16254-1-git-send-email-yangge1116@126.com
Link: https://lkml.kernel.org/r/1736582300-11364-1-git-send-email-yangge1116@126.com
Signed-off-by: yangge <yangge1116@126.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <21cnbao@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In the kernel, the zone's lowmem_reserve and _watermark, and the global
variable 'totalreserve_pages' depend on the value of managed_pages, but
after running adjust_managed_page_count, these values aren't updated,
which causes some problems.
For example, in a system with six 1GB large pages, we found that the value
of protection in zoneinfo (zone->lowmem_reserve), is not right. Its value
seems to be calculated from the initial managed_pages, but after the
managed_pages changed, was not updated. Only after reading the file
/proc/sys/vm/lowmem_reserve_ratio, updates happen.
read file /proc/sys/vm/lowmem_reserve_ratio:
lowmem_reserve_ratio_sysctl_handler
----setup_per_zone_lowmem_reserve
--------calculate_totalreserve_pages
protection changed after reading file:
[root@test ~]# cat /proc/zoneinfo | grep protection
protection: (0, 2719, 57360, 0)
protection: (0, 0, 54640, 0)
protection: (0, 0, 0, 0)
protection: (0, 0, 0, 0)
[root@test ~]# cat /proc/sys/vm/lowmem_reserve_ratio
256 256 32 0
[root@test ~]# cat /proc/zoneinfo | grep protection
protection: (0, 2735, 63524, 0)
protection: (0, 0, 60788, 0)
protection: (0, 0, 0, 0)
protection: (0, 0, 0, 0)
lowmem_reserve increased also makes the totalreserve_pages increased,
which causes a decrease in available memory. The one above is just a test
machine, and the increase is not significant. On our online machine, the
reserved memory will increase by several GB due to reading this file. It
is clearly unreasonable to cause a sharp drop in available memory just by
reading a file.
In this patch, we update reserve memory when update managed_pages, The
size of reserved memory becomes stable. But it seems that the _watermark
should also be updated along with the managed_pages. We have not done it
because we are unsure if it is reasonable to set the watermark through the
initial managed_pages. If it is not reasonable, we will propose new
patch.
Link: https://lkml.kernel.org/r/20241225021034.45693-1-15645113830zzh@gmail.com
Signed-off-by: zihan zhou <15645113830zzh@gmail.com>
Signed-off-by: yaowenchao <yaowenchao@jd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm: don't use __GFP_HARDWALL when migrating remote pages".
__GFP_HARDWALL means that we will be respecting the cpuset of the caller
when allocating a page. However, when we are migrating remote allocations
(pages allocated from other context), the cpuset of the current context is
irrelevant.
For memory offlining + alloc_contig_*(), this is rather obvious. There
might be other such page migration users, let's start with the obvious
ones.
This patch (of 2):
We'll migrate pages allocated by other contexts; respecting the cpuset of
the alloc_contig*() caller when allocating a migration target does not
make sense.
Drop the __GFP_HARDWALL.
Note that in an ideal world, migration code could figure out the cpuset
of the original context and take that into consideration.
Link: https://lkml.kernel.org/r/20241205090508.2095225-1-david@redhat.com
Link: https://lkml.kernel.org/r/20241205090508.2095225-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In the __GFP_COMP case, we already pass the gfp_flags to
prep_new_page()->post_alloc_hook(). However, in the !__GFP_COMP case, we
essentially pass only hardcoded __GFP_MOVABLE to post_alloc_hook(),
preventing some action modifiers from being effective..
Let's pass our now properly adjusted gfp flags there as well.
This way, we can now support __GFP_ZERO for alloc_contig_*().
As a side effect, we now also support __GFP_SKIP_ZERO and__GFP_ZEROTAGS;
but we'll keep the more special stuff (KASAN, NOLOCKDEP) disabled for now.
It's worth noting that with __GFP_ZERO, we might unnecessarily zero pages
when we have to release part of our range using free_contig_range() again.
This can be optimized in the future, if ever required; the caller we'll
be converting (powernv/memtrace) next won't trigger this.
Link: https://lkml.kernel.org/r/20241203094732.200195-6-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naveen N Rao <naveen@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
It's all a bit complicated for alloc_contig_range(). For example, we
don't support many flags, so let's start bailing out on unsupported ones
-- ignoring the placement hints, as we are already given the range to
allocate.
While we currently set cc.gfp_mask, in __alloc_contig_migrate_range() we
simply create yet another GFP mask whereby we ignore the reclaim flags
specify by the caller. That looks very inconsistent.
Let's clean it up, constructing the gfp flags used for
compaction/migration exactly once. Update the documentation of the
gfp_mask parameter for alloc_contig_range() and alloc_contig_pages().
Link: https://lkml.kernel.org/r/20241203094732.200195-5-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naveen N Rao <naveen@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The single user is in page_alloc.c.
Link: https://lkml.kernel.org/r/20241203094732.200195-4-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naveen N Rao <naveen@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The parameter is unused, so let's stop passing it.
Link: https://lkml.kernel.org/r/20241203094732.200195-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naveen N Rao <naveen@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In the near future, we want to have a single way to handover PageOffline
pages to the buddy, whereby they could have:
(a) Never been exposed to the buddy before: kept PageOffline when onlining
the memory block.
(b) Been allocated from the buddy, for example using
alloc_contig_range() to then be set PageOffline,
Let's start by making generic_online_page()->__free_pages_core() less
special compared to ordinary page freeing (e.g., free_contig_range()),
and perform the debug_pagealloc_map_pages() call unconditionally, even
when the online callback might decide to keep the pages offline.
All pages are already initialized with PageOffline, so nobody touches them
either way.
Link: https://lkml.kernel.org/r/20241203102050.223318-1-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Defer the initialisation of the page refcount to the new __alloc_pages()
wrapper and turn the old __alloc_pages() into __alloc_frozen_pages().
Link: https://lkml.kernel.org/r/20241125210149.2976098-14-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Remove some code duplication by calling set_page_refcounted() at the end
of __alloc_pages() instead of after each call that can allocate a page.
That means that we free a frozen page if we've exceeded the allowed memcg
memory.
Link: https://lkml.kernel.org/r/20241125210149.2976098-13-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In preparation for allocating frozen pages, stop initialising the page
refcount in __alloc_pages_slowpath().
Link: https://lkml.kernel.org/r/20241125210149.2976098-12-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In preparation for allocating frozen pages, stop initialising the page
refcount in __alloc_pages_direct_reclaim().
Link: https://lkml.kernel.org/r/20241125210149.2976098-11-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In preparation for allocating frozen pages, stop initialising the page
refcount in __alloc_pages_direct_compact().
Link: https://lkml.kernel.org/r/20241125210149.2976098-10-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In preparation for allocating frozen pages, stop initialising the page
refcount in __alloc_pages_may_oom().
Link: https://lkml.kernel.org/r/20241125210149.2976098-9-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In preparation for allocating frozen pages, stop initialising the page
refcount in __alloc_pages_cpuset_fallback().
Link: https://lkml.kernel.org/r/20241125210149.2976098-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In preparation for allocating frozen pages, stop initialising the page
refcount in get_page_from_freelist().
Link: https://lkml.kernel.org/r/20241125210149.2976098-7-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In preparation for allocating frozen pages, stop initialising the page
refcount in prep_new_page().
Link: https://lkml.kernel.org/r/20241125210149.2976098-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In preparation for allocating frozen pages, stop initialising the page
refcount in post_alloc_hook().
Link: https://lkml.kernel.org/r/20241125210149.2976098-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We already have the concept of "frozen pages" (eg page_ref_freeze()), so
let's not complicate things by also having the concept of "unref pages".
Link: https://lkml.kernel.org/r/20241125210149.2976098-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Allocate and free frozen pages", v3.
Slab does not need to use the page refcount at all, and it can avoid an
atomic operation on page free. Hugetlb wants to delay setting the
refcount until it has assembled a complete gigantic page. We already have
the ability to freeze a page (safely reduce its reference count to 0), so
this patchset adds APIs to allocate and free pages which are in a frozen
state.
This patchset is also a step towards the Glorious Future in which struct
page doesn't have a refcount; the users which need a refcount will have
one in their per-allocation memdesc.
This patch (of 15):
Save 17 bytes of text by calculating page_zone() once instead of twice.
Link: https://lkml.kernel.org/r/20241125210149.2976098-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20241125210149.2976098-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In split_large_buddy(), we might call pfn_to_page() on a PFN that might
not exist. In corner cases, such as when freeing the highest pageblock in
the last memory section, this could result with CONFIG_SPARSEMEM &&
!CONFIG_SPARSEMEM_EXTREME in __pfn_to_section() returning NULL and and
__section_mem_map_addr() dereferencing that NULL pointer.
Let's fix it, and avoid doing a pfn_to_page() call for the first
iteration, where we already have the page.
So far this was found by code inspection, but let's just CC stable as the
fix is easy.
Link: https://lkml.kernel.org/r/20241210093437.174413-1-david@redhat.com
Fixes: fd919a85cd ("mm: page_isolation: prepare for hygienic freelists")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Closes: https://lkml.kernel.org/r/e1a898ba-a717-4d20-9144-29df1a6c8813@suse.cz
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Yu Zhao <yuzhao@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Sergey Senozhatsky improves zram's post-processing selection algorithm.
This leads to improved memory savings.
- Wei Yang has gone to town on the mapletree code, contributing several
series which clean up the implementation:
- "refine mas_mab_cp()"
- "Reduce the space to be cleared for maple_big_node"
- "maple_tree: simplify mas_push_node()"
- "Following cleanup after introduce mas_wr_store_type()"
- "refine storing null"
- The series "selftests/mm: hugetlb_fault_after_madv improvements" from
David Hildenbrand fixes this selftest for s390.
- The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng
implements some rationaizations and cleanups in the page mapping code.
- The series "mm: optimize shadow entries removal" from Shakeel Butt
optimizes the file truncation code by speeding up the handling of shadow
entries.
- The series "Remove PageKsm()" from Matthew Wilcox completes the
migration of this flag over to being a folio-based flag.
- The series "Unify hugetlb into arch_get_unmapped_area functions" from
Oscar Salvador implements a bunch of consolidations and cleanups in the
hugetlb code.
- The series "Do not shatter hugezeropage on wp-fault" from Dev Jain
takes away the wp-fault time practice of turning a huge zero page into
small pages. Instead we replace the whole thing with a THP. More
consistent cleaner and potentiall saves a large number of pagefaults.
- The series "percpu: Add a test case and fix for clang" from Andy
Shevchenko enhances and fixes the kernel's built in percpu test code.
- The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett
optimizes mremap() by avoiding doing things which we didn't need to do.
- The series "Improve the tmpfs large folio read performance" from
Baolin Wang teaches tmpfs to copy data into userspace at the folio size
rather than as individual pages. A 20% speedup was observed.
- The series "mm/damon/vaddr: Fix issue in
damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON splitting.
- The series "memcg-v1: fully deprecate charge moving" from Shakeel Butt
removes the long-deprecated memcgv2 charge moving feature.
- The series "fix error handling in mmap_region() and refactor" from
Lorenzo Stoakes cleanup up some of the mmap() error handling and
addresses some potential performance issues.
- The series "x86/module: use large ROX pages for text allocations" from
Mike Rapoport teaches x86 to use large pages for read-only-execute
module text.
- The series "page allocation tag compression" from Suren Baghdasaryan
is followon maintenance work for the new page allocation profiling
feature.
- The series "page->index removals in mm" from Matthew Wilcox remove
most references to page->index in mm/. A slow march towards shrinking
struct page.
- The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs
interface tests" from Andrew Paniakin performs maintenance work for
DAMON's self testing code.
- The series "mm: zswap swap-out of large folios" from Kanchana Sridhar
improves zswap's batching of compression and decompression. It is a
step along the way towards using Intel IAA hardware acceleration for
this zswap operation.
- The series "kasan: migrate the last module test to kunit" from
Sabyrzhan Tasbolatov completes the migration of the KASAN built-in tests
over to the KUnit framework.
- The series "implement lightweight guard pages" from Lorenzo Stoakes
permits userapace to place fault-generating guard pages within a single
VMA, rather than requiring that multiple VMAs be created for this.
Improved efficiencies for userspace memory allocators are expected.
- The series "memcg: tracepoint for flushing stats" from JP Kobryn uses
tracepoints to provide increased visibility into memcg stats flushing
activity.
- The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky
fixes a zram buglet which potentially affected performance.
- The series "mm: add more kernel parameters to control mTHP" from
Maíra Canal enhances our ability to control/configuremultisize THP from
the kernel boot command line.
- The series "kasan: few improvements on kunit tests" from Sabyrzhan
Tasbolatov has a couple of fixups for the KASAN KUnit tests.
- The series "mm/list_lru: Split list_lru lock into per-cgroup scope"
from Kairui Song optimizes list_lru memory utilization when lockdep is
enabled.
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Merge tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- The series "zram: optimal post-processing target selection" from
Sergey Senozhatsky improves zram's post-processing selection
algorithm. This leads to improved memory savings.
- Wei Yang has gone to town on the mapletree code, contributing several
series which clean up the implementation:
- "refine mas_mab_cp()"
- "Reduce the space to be cleared for maple_big_node"
- "maple_tree: simplify mas_push_node()"
- "Following cleanup after introduce mas_wr_store_type()"
- "refine storing null"
- The series "selftests/mm: hugetlb_fault_after_madv improvements" from
David Hildenbrand fixes this selftest for s390.
- The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng
implements some rationaizations and cleanups in the page mapping
code.
- The series "mm: optimize shadow entries removal" from Shakeel Butt
optimizes the file truncation code by speeding up the handling of
shadow entries.
- The series "Remove PageKsm()" from Matthew Wilcox completes the
migration of this flag over to being a folio-based flag.
- The series "Unify hugetlb into arch_get_unmapped_area functions" from
Oscar Salvador implements a bunch of consolidations and cleanups in
the hugetlb code.
- The series "Do not shatter hugezeropage on wp-fault" from Dev Jain
takes away the wp-fault time practice of turning a huge zero page
into small pages. Instead we replace the whole thing with a THP. More
consistent cleaner and potentiall saves a large number of pagefaults.
- The series "percpu: Add a test case and fix for clang" from Andy
Shevchenko enhances and fixes the kernel's built in percpu test code.
- The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett
optimizes mremap() by avoiding doing things which we didn't need to
do.
- The series "Improve the tmpfs large folio read performance" from
Baolin Wang teaches tmpfs to copy data into userspace at the folio
size rather than as individual pages. A 20% speedup was observed.
- The series "mm/damon/vaddr: Fix issue in
damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON
splitting.
- The series "memcg-v1: fully deprecate charge moving" from Shakeel
Butt removes the long-deprecated memcgv2 charge moving feature.
- The series "fix error handling in mmap_region() and refactor" from
Lorenzo Stoakes cleanup up some of the mmap() error handling and
addresses some potential performance issues.
- The series "x86/module: use large ROX pages for text allocations"
from Mike Rapoport teaches x86 to use large pages for
read-only-execute module text.
- The series "page allocation tag compression" from Suren Baghdasaryan
is followon maintenance work for the new page allocation profiling
feature.
- The series "page->index removals in mm" from Matthew Wilcox remove
most references to page->index in mm/. A slow march towards shrinking
struct page.
- The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs
interface tests" from Andrew Paniakin performs maintenance work for
DAMON's self testing code.
- The series "mm: zswap swap-out of large folios" from Kanchana Sridhar
improves zswap's batching of compression and decompression. It is a
step along the way towards using Intel IAA hardware acceleration for
this zswap operation.
- The series "kasan: migrate the last module test to kunit" from
Sabyrzhan Tasbolatov completes the migration of the KASAN built-in
tests over to the KUnit framework.
- The series "implement lightweight guard pages" from Lorenzo Stoakes
permits userapace to place fault-generating guard pages within a
single VMA, rather than requiring that multiple VMAs be created for
this. Improved efficiencies for userspace memory allocators are
expected.
- The series "memcg: tracepoint for flushing stats" from JP Kobryn uses
tracepoints to provide increased visibility into memcg stats flushing
activity.
- The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky
fixes a zram buglet which potentially affected performance.
- The series "mm: add more kernel parameters to control mTHP" from
Maíra Canal enhances our ability to control/configuremultisize THP
from the kernel boot command line.
- The series "kasan: few improvements on kunit tests" from Sabyrzhan
Tasbolatov has a couple of fixups for the KASAN KUnit tests.
- The series "mm/list_lru: Split list_lru lock into per-cgroup scope"
from Kairui Song optimizes list_lru memory utilization when lockdep
is enabled.
* tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (215 commits)
cma: enforce non-zero pageblock_order during cma_init_reserved_mem()
mm/kfence: add a new kunit test test_use_after_free_read_nofault()
zram: fix NULL pointer in comp_algorithm_show()
memcg/hugetlb: add hugeTLB counters to memcg
vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event
mm: mmap_lock: check trace_mmap_lock_$type_enabled() instead of regcount
zram: ZRAM_DEF_COMP should depend on ZRAM
MAINTAINERS/MEMORY MANAGEMENT: add document files for mm
Docs/mm/damon: recommend academic papers to read and/or cite
mm: define general function pXd_init()
kmemleak: iommu/iova: fix transient kmemleak false positive
mm/list_lru: simplify the list_lru walk callback function
mm/list_lru: split the lock to per-cgroup scope
mm/list_lru: simplify reparenting and initial allocation
mm/list_lru: code clean up for reparenting
mm/list_lru: don't export list_lru_add
mm/list_lru: don't pass unnecessary key parameters
kasan: add kunit tests for kmalloc_track_caller, kmalloc_node_track_caller
kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW
kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols
...
The most significant set of changes is the per netns RTNL. The new
behavior is disabled by default, regression risk should be contained.
Notably the new config knob PTP_1588_CLOCK_VMCLOCK will inherit its
default value from PTP_1588_CLOCK_KVM, as the first is intended to be
a more reliable replacement for the latter.
Core
----
- Started a very large, in-progress, effort to make the RTNL lock
scope per network-namespace, thus reducing the lock contention
significantly in the containerized use-case, comprising:
- RCU-ified some relevant slices of the FIB control path
- introduce basic per netns locking helpers
- namespacified the IPv4 address hash table
- remove rtnl_register{,_module}() in favour of rtnl_register_many()
- refactor rtnl_{new,del,set}link() moving as much validation as
possible out of RTNL lock
- convert all phonet doit() and dumpit() handlers to RCU
- convert IPv4 addresses manipulation to per-netns RTNL
- convert virtual interface creation to per-netns RTNL
the per-netns lock infra is guarded by the CONFIG_DEBUG_NET_SMALL_RTNL
knob, disabled by default ad interim.
- Introduce NAPI suspension, to efficiently switching between busy
polling (NAPI processing suspended) and normal processing.
- Migrate the IPv4 routing input, output and control path from direct
ToS usage to DSCP macros. This is a work in progress to make ECN
handling consistent and reliable.
- Add drop reasons support to the IPv4 rotue input path, allowing
better introspection in case of packets drop.
- Make FIB seqnum lockless, dropping RTNL protection for read
access.
- Make inet{,v6} addresses hashing less predicable.
- Allow providing timestamp OPT_ID via cmsg, to correlate TX packets
and timestamps
Things we sprinkled into general kernel code
--------------------------------------------
- Add small file operations for debugfs, to reduce the struct ops size.
- Refactoring and optimization for the implementation of page_frag API,
This is a preparatory work to consolidate the page_frag
implementation.
Netfilter
---------
- Optimize set element transactions to reduce memory consumption
- Extended netlink error reporting for attribute parser failure.
- Make legacy xtables configs user selectable, giving users
the option to configure iptables without enabling any other config.
- Address a lot of false-positive RCU issues, pointed by recent
CI improvements.
BPF
---
- Put xsk sockets on a struct diet and add various cleanups. Overall,
this helps to bump performance by 12% for some workloads.
- Extend BPF selftests to increase coverage of XDP features in
combination with BPF cpumap.
- Optimize and homogenize bpf_csum_diff helper for all archs and also
add a batch of new BPF selftests for it.
- Extend netkit with an option to delegate skb->{mark,priority}
scrubbing to its BPF program.
- Make the bpf_get_netns_cookie() helper available also to tc(x) BPF
programs.
Protocols
---------
- Introduces 4-tuple hash for connected udp sockets, speeding-up
significantly connected sockets lookup.
- Add a fastpath for some TCP timers that usually expires after close,
the socket lock contention.
- Add inbound and outbound xfrm state caches to speed up state lookups.
- Avoid sending MPTCP advertisements on stale subflows, reducing
risks on loosing them.
- Make neighbours table flushing more scalable, maintaining per device
neigh lists.
Driver API
----------
- Introduce a unified interface to configure transmission H/W shaping,
and expose it to user-space via generic-netlink.
- Add support for per-NAPI config via netlink. This makes napi
configuration persistent across queues removal and re-creation.
Requires driver updates, currently supported drivers are:
nVidia/Mellanox mlx4 and mlx5, Broadcom brcm and Intel ice.
- Add ethtool support for writing SFP / PHY firmware blocks.
- Track RSS context allocation from ethtool core.
- Implement support for mirroring to DSA CPU port, via TC mirror
offload.
- Consolidate FDB updates notification, to avoid duplicates on
device-specific entries.
- Expose DPLL clock quality level to the user-space.
- Support master-slave PHY config via device tree.
Tests and tooling
-----------------
- forwarding: introduce deferred commands, to simplify
the cleanup phase
Drivers
-------
- Updated several drivers - Amazon vNic, Google vNic, Microsoft vNic,
Intel e1000e and Broadcom Tigon3 - to use netdev-genl to link the
IRQs and queues to NAPI IDs, allowing busy polling and better
introspection.
- Ethernet high-speed NICs:
- nVidia/Mellanox:
- mlx5:
- a large refactor to implement support for cross E-Switch
scheduling
- refactor H/W conter management to let it scale better
- H/W GRO cleanups
- Intel (100G, ice)::
- adds support for ethtool reset
- implement support for per TX queue H/W shaping
- AMD/Solarflare:
- implement per device queue stats support
- Broadcom (bnxt):
- improve wildcard l4proto on IPv4/IPv6 ntuple rules
- Marvell Octeon:
- Adds representor support for each Resource Virtualization Unit
(RVU) device.
- Hisilicon:
- adds support for the BMC Gigabit Ethernet
- IBM (EMAC):
- driver cleanup and modernization
- Cisco (VIC):
- raise the queues number limit to 256
- Ethernet virtual:
- Google vNIC:
- implements page pool support
- macsec:
- inherit lower device's features and TSO limits when offloading
- virtio_net:
- enable premapped mode by default
- support for XDP socket(AF_XDP) zerocopy TX
- wireguard:
- set the TSO max size to be GSO_MAX_SIZE, to aggregate larger
packets.
- Ethernet NICs embedded and virtual:
- Broadcom ASP:
- enable software timestamping
- Freescale:
- add enetc4 PF driver
- MediaTek: Airoha SoC:
- implement BQL support
- RealTek r8169:
- enable TSO by default on r8168/r8125
- implement extended ethtool stats
- Renesas AVB:
- enable TX checksum offload
- Synopsys (stmmac):
- support header splitting for vlan tagged packets
- move common code for DWMAC4 and DWXGMAC into a separate FPE
module.
- Add the dwmac driver support for T-HEAD TH1520 SoC
- Synopsys (xpcs):
- driver refactor and cleanup
- TI:
- icssg_prueth: add VLAN offload support
- Xilinx emaclite:
- adds clock support
- Ethernet switches:
- Microchip:
- implement support for the lan969x Ethernet switch family
- add LAN9646 switch support to KSZ DSA driver
- Ethernet PHYs:
- Marvel: 88q2x: enable auto negotiation
- Microchip: add support for LAN865X Rev B1 and LAN867X Rev C1/C2
- PTP:
- Add support for the Amazon virtual clock device
- Add PtP driver for s390 clocks
- WiFi:
- mac80211
- EHT 1024 aggregation size for transmissions
- new operation to indicate that a new interface is to be added
- support radio separation of multi-band devices
- move wireless extension spy implementation to libiw
- Broadcom:
- brcmfmac: optional LPO clock support
- Microchip:
- add support for Atmel WILC3000
- Qualcomm (ath12k):
- firmware coredump collection support
- add debugfs support for a multitude of statistics
- Qualcomm (ath5k):
- Arcadyan ARV45XX AR2417 & Gigaset SX76[23] AR241[34]A support
- Realtek:
- rtw88: 8821au and 8812au USB adapters support
- rtw89: add thermal protection
- rtw89: fine tune BT-coexsitence to improve user experience
- rtw89: firmware secure boot for WiFi 6 chip
- Bluetooth
- add Qualcomm WCN785x support for ids Foxconn 0xe0fc/0xe0f3 and
0x13d3:0x3623
- add Realtek RTL8852BE support for id Foxconn 0xe123
- add MediaTek MT7920 support for wireless module ids
- btintel_pcie: add handshake between driver and firmware
- btintel_pcie: add recovery mechanism
- btnxpuart: add GPIO support to power save feature
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'net-next-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from Paolo Abeni:
"The most significant set of changes is the per netns RTNL. The new
behavior is disabled by default, regression risk should be contained.
Notably the new config knob PTP_1588_CLOCK_VMCLOCK will inherit its
default value from PTP_1588_CLOCK_KVM, as the first is intended to be
a more reliable replacement for the latter.
Core:
- Started a very large, in-progress, effort to make the RTNL lock
scope per network-namespace, thus reducing the lock contention
significantly in the containerized use-case, comprising:
- RCU-ified some relevant slices of the FIB control path
- introduce basic per netns locking helpers
- namespacified the IPv4 address hash table
- remove rtnl_register{,_module}() in favour of
rtnl_register_many()
- refactor rtnl_{new,del,set}link() moving as much validation as
possible out of RTNL lock
- convert all phonet doit() and dumpit() handlers to RCU
- convert IPv4 addresses manipulation to per-netns RTNL
- convert virtual interface creation to per-netns RTNL
the per-netns lock infrastructure is guarded by the
CONFIG_DEBUG_NET_SMALL_RTNL knob, disabled by default ad interim.
- Introduce NAPI suspension, to efficiently switching between busy
polling (NAPI processing suspended) and normal processing.
- Migrate the IPv4 routing input, output and control path from direct
ToS usage to DSCP macros. This is a work in progress to make ECN
handling consistent and reliable.
- Add drop reasons support to the IPv4 rotue input path, allowing
better introspection in case of packets drop.
- Make FIB seqnum lockless, dropping RTNL protection for read access.
- Make inet{,v6} addresses hashing less predicable.
- Allow providing timestamp OPT_ID via cmsg, to correlate TX packets
and timestamps
Things we sprinkled into general kernel code:
- Add small file operations for debugfs, to reduce the struct ops
size.
- Refactoring and optimization for the implementation of page_frag
API, This is a preparatory work to consolidate the page_frag
implementation.
Netfilter:
- Optimize set element transactions to reduce memory consumption
- Extended netlink error reporting for attribute parser failure.
- Make legacy xtables configs user selectable, giving users the
option to configure iptables without enabling any other config.
- Address a lot of false-positive RCU issues, pointed by recent CI
improvements.
BPF:
- Put xsk sockets on a struct diet and add various cleanups. Overall,
this helps to bump performance by 12% for some workloads.
- Extend BPF selftests to increase coverage of XDP features in
combination with BPF cpumap.
- Optimize and homogenize bpf_csum_diff helper for all archs and also
add a batch of new BPF selftests for it.
- Extend netkit with an option to delegate skb->{mark,priority}
scrubbing to its BPF program.
- Make the bpf_get_netns_cookie() helper available also to tc(x) BPF
programs.
Protocols:
- Introduces 4-tuple hash for connected udp sockets, speeding-up
significantly connected sockets lookup.
- Add a fastpath for some TCP timers that usually expires after
close, the socket lock contention.
- Add inbound and outbound xfrm state caches to speed up state
lookups.
- Avoid sending MPTCP advertisements on stale subflows, reducing
risks on loosing them.
- Make neighbours table flushing more scalable, maintaining per
device neigh lists.
Driver API:
- Introduce a unified interface to configure transmission H/W
shaping, and expose it to user-space via generic-netlink.
- Add support for per-NAPI config via netlink. This makes napi
configuration persistent across queues removal and re-creation.
Requires driver updates, currently supported drivers are:
nVidia/Mellanox mlx4 and mlx5, Broadcom brcm and Intel ice.
- Add ethtool support for writing SFP / PHY firmware blocks.
- Track RSS context allocation from ethtool core.
- Implement support for mirroring to DSA CPU port, via TC mirror
offload.
- Consolidate FDB updates notification, to avoid duplicates on
device-specific entries.
- Expose DPLL clock quality level to the user-space.
- Support master-slave PHY config via device tree.
Tests and tooling:
- forwarding: introduce deferred commands, to simplify the cleanup
phase
Drivers:
- Updated several drivers - Amazon vNic, Google vNic, Microsoft vNic,
Intel e1000e and Broadcom Tigon3 - to use netdev-genl to link the
IRQs and queues to NAPI IDs, allowing busy polling and better
introspection.
- Ethernet high-speed NICs:
- nVidia/Mellanox:
- mlx5:
- a large refactor to implement support for cross E-Switch
scheduling
- refactor H/W conter management to let it scale better
- H/W GRO cleanups
- Intel (100G, ice)::
- add support for ethtool reset
- implement support for per TX queue H/W shaping
- AMD/Solarflare:
- implement per device queue stats support
- Broadcom (bnxt):
- improve wildcard l4proto on IPv4/IPv6 ntuple rules
- Marvell Octeon:
- Add representor support for each Resource Virtualization Unit
(RVU) device.
- Hisilicon:
- add support for the BMC Gigabit Ethernet
- IBM (EMAC):
- driver cleanup and modernization
- Cisco (VIC):
- raise the queues number limit to 256
- Ethernet virtual:
- Google vNIC:
- implement page pool support
- macsec:
- inherit lower device's features and TSO limits when
offloading
- virtio_net:
- enable premapped mode by default
- support for XDP socket(AF_XDP) zerocopy TX
- wireguard:
- set the TSO max size to be GSO_MAX_SIZE, to aggregate larger
packets.
- Ethernet NICs embedded and virtual:
- Broadcom ASP:
- enable software timestamping
- Freescale:
- add enetc4 PF driver
- MediaTek: Airoha SoC:
- implement BQL support
- RealTek r8169:
- enable TSO by default on r8168/r8125
- implement extended ethtool stats
- Renesas AVB:
- enable TX checksum offload
- Synopsys (stmmac):
- support header splitting for vlan tagged packets
- move common code for DWMAC4 and DWXGMAC into a separate FPE
module.
- add dwmac driver support for T-HEAD TH1520 SoC
- Synopsys (xpcs):
- driver refactor and cleanup
- TI:
- icssg_prueth: add VLAN offload support
- Xilinx emaclite:
- add clock support
- Ethernet switches:
- Microchip:
- implement support for the lan969x Ethernet switch family
- add LAN9646 switch support to KSZ DSA driver
- Ethernet PHYs:
- Marvel: 88q2x: enable auto negotiation
- Microchip: add support for LAN865X Rev B1 and LAN867X Rev C1/C2
- PTP:
- Add support for the Amazon virtual clock device
- Add PtP driver for s390 clocks
- WiFi:
- mac80211
- EHT 1024 aggregation size for transmissions
- new operation to indicate that a new interface is to be added
- support radio separation of multi-band devices
- move wireless extension spy implementation to libiw
- Broadcom:
- brcmfmac: optional LPO clock support
- Microchip:
- add support for Atmel WILC3000
- Qualcomm (ath12k):
- firmware coredump collection support
- add debugfs support for a multitude of statistics
- Qualcomm (ath5k):
- Arcadyan ARV45XX AR2417 & Gigaset SX76[23] AR241[34]A support
- Realtek:
- rtw88: 8821au and 8812au USB adapters support
- rtw89: add thermal protection
- rtw89: fine tune BT-coexsitence to improve user experience
- rtw89: firmware secure boot for WiFi 6 chip
- Bluetooth
- add Qualcomm WCN785x support for ids Foxconn 0xe0fc/0xe0f3 and
0x13d3:0x3623
- add Realtek RTL8852BE support for id Foxconn 0xe123
- add MediaTek MT7920 support for wireless module ids
- btintel_pcie: add handshake between driver and firmware
- btintel_pcie: add recovery mechanism
- btnxpuart: add GPIO support to power save feature"
* tag 'net-next-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1475 commits)
mm: page_frag: fix a compile error when kernel is not compiled
Documentation: tipc: fix formatting issue in tipc.rst
selftests: nic_performance: Add selftest for performance of NIC driver
selftests: nic_link_layer: Add selftest case for speed and duplex states
selftests: nic_link_layer: Add link layer selftest for NIC driver
bnxt_en: Add FW trace coredump segments to the coredump
bnxt_en: Add a new ethtool -W dump flag
bnxt_en: Add 2 parameters to bnxt_fill_coredump_seg_hdr()
bnxt_en: Add functions to copy host context memory
bnxt_en: Do not free FW log context memory
bnxt_en: Manage the FW trace context memory
bnxt_en: Allocate backing store memory for FW trace logs
bnxt_en: Add a 'force' parameter to bnxt_free_ctx_mem()
bnxt_en: Refactor bnxt_free_ctx_mem()
bnxt_en: Add mem_valid bit to struct bnxt_ctx_mem_type
bnxt_en: Update firmware interface spec to 1.10.3.85
selftests/bpf: Add some tests with sockmap SK_PASS
bpf: fix recursive lock when verdict program return SK_PASS
wireguard: device: support big tcp GSO
wireguard: selftests: load nf_conntrack if not present
...
We triggered a NULL pointer dereference for ac.preferred_zoneref->zone in
alloc_pages_bulk_noprof() when the task is migrated between cpusets.
When cpuset is enabled, in prepare_alloc_pages(), ac->nodemask may be
¤t->mems_allowed. when first_zones_zonelist() is called to find
preferred_zoneref, the ac->nodemask may be modified concurrently if the
task is migrated between different cpusets. Assuming we have 2 NUMA Node,
when traversing Node1 in ac->zonelist, the nodemask is 2, and when
traversing Node2 in ac->zonelist, the nodemask is 1. As a result, the
ac->preferred_zoneref points to NULL zone.
In alloc_pages_bulk_noprof(), for_each_zone_zonelist_nodemask() finds a
allowable zone and calls zonelist_node_idx(ac.preferred_zoneref), leading
to NULL pointer dereference.
__alloc_pages_noprof() fixes this issue by checking NULL pointer in commit
ea57485af8 ("mm, page_alloc: fix check for NULL preferred_zone") and
commit df76cee6bb ("mm, page_alloc: remove redundant checks from alloc
fastpath").
To fix it, check NULL pointer for preferred_zoneref->zone.
Link: https://lkml.kernel.org/r/20241113083235.166798-1-tujinjiang@huawei.com
Fixes: 387ba26fb1 ("mm/page_alloc: add a bulk page allocator")
Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alexander Lobakin <alobakin@pm.me>
Cc: David Hildenbrand <david@redhat.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pick up e7ac4daeed ("mm: count zeromap read and set for swapout and
swapin") in order to move
mm: define obj_cgroup_get() if CONFIG_MEMCG is not defined
mm: zswap: modify zswap_compress() to accept a page instead of a folio
mm: zswap: rename zswap_pool_get() to zswap_pool_tryget()
mm: zswap: modify zswap_stored_pages to be atomic_long_t
mm: zswap: support large folios in zswap_store()
mm: swap: count successful large folio zswap stores in hugepage zswpout stats
mm: zswap: zswap_store_page() will initialize entry after adding to xarray.
mm: add per-order mTHP swpin counters
from mm-unstable into mm-stable.
OOM kills due to vastly overestimated free highatomic reserves were
observed:
... invoked oom-killer: gfp_mask=0x100cca(GFP_HIGHUSER_MOVABLE), order=0 ...
Node 0 Normal free:1482936kB boost:0kB min:410416kB low:739404kB high:1068392kB reserved_highatomic:1073152KB ...
Node 0 Normal: 1292*4kB (ME) 1920*8kB (E) 383*16kB (UE) 220*32kB (ME) 340*64kB (E) 2155*128kB (UE) 3243*256kB (UE) 615*512kB (U) 1*1024kB (M) 0*2048kB 0*4096kB = 1477408kB
The second line above shows that the OOM kill was due to the following
condition:
free (1482936kB) - reserved_highatomic (1073152kB) = 409784KB < min (410416kB)
And the third line shows there were no free pages in any
MIGRATE_HIGHATOMIC pageblocks, which otherwise would show up as type 'H'.
Therefore __zone_watermark_unusable_free() underestimated the usable free
memory by over 1GB, which resulted in the unnecessary OOM kill above.
The comments in __zone_watermark_unusable_free() warns about the potential
risk, i.e.,
If the caller does not have rights to reserves below the min
watermark then subtract the high-atomic reserves. This will
over-estimate the size of the atomic reserve but it avoids a search.
However, it is possible to keep track of free pages in reserved highatomic
pageblocks with a new per-zone counter nr_free_highatomic protected by the
zone lock, to avoid a search when calculating the usable free memory. And
the cost would be minimal, i.e., simple arithmetics in the highatomic
alloc/free/move paths.
Note that since nr_free_highatomic can be relatively small, using a
per-cpu counter might cause too much drift and defeat its purpose, in
addition to the extra memory overhead.
Dependson e0932b6c1f ("mm: page_alloc: consolidate free page accounting") - see [1]
[akpm@linux-foundation.org: s/if/else if/, per Johannes, stealth whitespace tweak]
Link: https://lkml.kernel.org/r/20241028182653.3420139-1-yuzhao@google.com
Link: https://lkml.kernel.org/r/0d0ddb33-fcdc-43e2-801f-0c1df2031afb@suse.cz [1]
Fixes: 0aaa29a56e ("mm, page_alloc: reserve pageblocks for high-order atomic allocations on demand")
Signed-off-by: Yu Zhao <yuzhao@google.com>
Reported-by: Link Lin <linkl@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Recent changes are putting more pressure on THP deferred split queues:
under load revealing long-standing races, causing list_del corruptions,
"Bad page state"s and worse (I keep BUGs in both of those, so usually
don't get to see how badly they end up without). The relevant recent
changes being 6.8's mTHP, 6.10's mTHP swapout, and 6.12's mTHP swapin,
improved swap allocation, and underused THP splitting.
Before fixing locking: rename misleading folio_undo_large_rmappable(),
which does not undo large_rmappable, to folio_unqueue_deferred_split(),
which is what it does. But that and its out-of-line __callee are mm
internals of very limited usability: add comment and WARN_ON_ONCEs to
check usage; and return a bool to say if a deferred split was unqueued,
which can then be used in WARN_ON_ONCEs around safety checks (sparing
callers the arcane conditionals in __folio_unqueue_deferred_split()).
Just omit the folio_unqueue_deferred_split() from free_unref_folios(), all
of whose callers now call it beforehand (and if any forget then bad_page()
will tell) - except for its caller put_pages_list(), which itself no
longer has any callers (and will be deleted separately).
Swapout: mem_cgroup_swapout() has been resetting folio->memcg_data 0
without checking and unqueueing a THP folio from deferred split list;
which is unfortunate, since the split_queue_lock depends on the memcg
(when memcg is enabled); so swapout has been unqueueing such THPs later,
when freeing the folio, using the pgdat's lock instead: potentially
corrupting the memcg's list. __remove_mapping() has frozen refcount to 0
here, so no problem with calling folio_unqueue_deferred_split() before
resetting memcg_data.
That goes back to 5.4 commit 87eaceb3fa ("mm: thp: make deferred split
shrinker memcg aware"): which included a check on swapcache before adding
to deferred queue, but no check on deferred queue before adding THP to
swapcache. That worked fine with the usual sequence of events in reclaim
(though there were a couple of rare ways in which a THP on deferred queue
could have been swapped out), but 6.12 commit dafff3f4c8 ("mm: split
underused THPs") avoids splitting underused THPs in reclaim, which makes
swapcache THPs on deferred queue commonplace.
Keep the check on swapcache before adding to deferred queue? Yes: it is
no longer essential, but preserves the existing behaviour, and is likely
to be a worthwhile optimization (vmstat showed much more traffic on the
queue under swapping load if the check was removed); update its comment.
Memcg-v1 move (deprecated): mem_cgroup_move_account() has been changing
folio->memcg_data without checking and unqueueing a THP folio from the
deferred list, sometimes corrupting "from" memcg's list, like swapout.
Refcount is non-zero here, so folio_unqueue_deferred_split() can only be
used in a WARN_ON_ONCE to validate the fix, which must be done earlier:
mem_cgroup_move_charge_pte_range() first try to split the THP (splitting
of course unqueues), or skip it if that fails. Not ideal, but moving
charge has been requested, and khugepaged should repair the THP later:
nobody wants new custom unqueueing code just for this deprecated case.
The 87eaceb3fa commit did have the code to move from one deferred list
to another (but was not conscious of its unsafety while refcount non-0);
but that was removed by 5.6 commit fac0516b55 ("mm: thp: don't need care
deferred split queue in memcg charge move path"), which argued that the
existence of a PMD mapping guarantees that the THP cannot be on a deferred
list. As above, false in rare cases, and now commonly false.
Backport to 6.11 should be straightforward. Earlier backports must take
care that other _deferred_list fixes and dependencies are included. There
is not a strong case for backports, but they can fix cornercases.
Link: https://lkml.kernel.org/r/8dc111ae-f6db-2da7-b25c-7a20b1effe3b@google.com
Fixes: 87eaceb3fa ("mm: thp: make deferred split shrinker memcg aware")
Fixes: dafff3f4c8 ("mm: split underused THPs")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Recent changes are putting more pressure on THP deferred split queues:
under load revealing long-standing races, causing list_del corruptions,
"Bad page state"s and worse (I keep BUGs in both of those, so usually
don't get to see how badly they end up without). The relevant recent
changes being 6.8's mTHP, 6.10's mTHP swapout, and 6.12's mTHP swapin,
improved swap allocation, and underused THP splitting.
The new unlocked list_del_init() in deferred_split_scan() is buggy. I
gave bad advice, it looks plausible since that's a local on-stack list,
but the fact is that it can race with a third party freeing or migrating
the preceding folio (properly unqueueing it with refcount 0 while holding
split_queue_lock), thereby corrupting the list linkage.
The obvious answer would be to take split_queue_lock there: but it has a
long history of contention, so I'm reluctant to add to that. Instead,
make sure that there is always one safe (raised refcount) folio before, by
delaying its folio_put(). (And of course I was wrong to suggest updating
split_queue_len without the lock: leave that until the splice.)
And remove two over-eager partially_mapped checks, restoring those tests
to how they were before: if uncharge_folio() or free_tail_page_prepare()
finds _deferred_list non-empty, it's in trouble whether or not that folio
is partially_mapped (and the flag was already cleared in the latter case).
Link: https://lkml.kernel.org/r/81e34a8b-113a-0701-740e-2135c97eb1d7@google.com
Fixes: dafff3f4c8 ("mm: split underused THPs")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Usama Arif <usamaarif642@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: Zi Yan <ziy@nvidia.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Under memory pressure it's possible for GFP_ATOMIC order-0 allocations to
fail even though free pages are available in the highatomic reserves.
GFP_ATOMIC allocations cannot trigger unreserve_highatomic_pageblock()
since it's only run from reclaim.
Given that such allocations will pass the watermarks in
__zone_watermark_unusable_free(), it makes sense to fallback to highatomic
reserves the same way that ALLOC_OOM can.
This fixes order-0 page allocation failures observed on Cloudflare's fleet
when handling network packets:
kswapd1: page allocation failure: order:0, mode:0x820(GFP_ATOMIC),
nodemask=(null),cpuset=/,mems_allowed=0-7
CPU: 10 PID: 696 Comm: kswapd1 Kdump: loaded Tainted: G O 6.6.43-CUSTOM #1
Hardware name: MACHINE
Call Trace:
<IRQ>
dump_stack_lvl+0x3c/0x50
warn_alloc+0x13a/0x1c0
__alloc_pages_slowpath.constprop.0+0xc9d/0xd10
__alloc_pages+0x327/0x340
__napi_alloc_skb+0x16d/0x1f0
bnxt_rx_page_skb+0x96/0x1b0 [bnxt_en]
bnxt_rx_pkt+0x201/0x15e0 [bnxt_en]
__bnxt_poll_work+0x156/0x2b0 [bnxt_en]
bnxt_poll+0xd9/0x1c0 [bnxt_en]
__napi_poll+0x2b/0x1b0
bpf_trampoline_6442524138+0x7d/0x1000
__napi_poll+0x5/0x1b0
net_rx_action+0x342/0x740
handle_softirqs+0xcf/0x2b0
irq_exit_rcu+0x6c/0x90
sysvec_apic_timer_interrupt+0x72/0x90
</IRQ>
[mfleming@cloudflare.com: update comment]
Link: https://lkml.kernel.org/r/20241015125158.3597702-1-matt@readmodwrite.com
Link: https://lkml.kernel.org/r/20241011120737.3300370-1-matt@readmodwrite.com
Link: https://lore.kernel.org/all/CAGis_TWzSu=P7QJmjD58WWiu3zjMTVKSzdOwWE8ORaGytzWJwQ@mail.gmail.com/
Fixes: 1d91df85f3 ("mm/page_alloc: handle a missing case for memalloc_nocma_{save/restore} APIs")
Signed-off-by: Matt Fleming <mfleming@cloudflare.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
this pull request are:
"Align kvrealloc() with krealloc()" from Danilo Krummrich. Adds
consistency to the APIs and behaviour of these two core allocation
functions. This also simplifies/enables Rustification.
"Some cleanups for shmem" from Baolin Wang. No functional changes - mode
code reuse, better function naming, logic simplifications.
"mm: some small page fault cleanups" from Josef Bacik. No functional
changes - code cleanups only.
"Various memory tiering fixes" from Zi Yan. A small fix and a little
cleanup.
"mm/swap: remove boilerplate" from Yu Zhao. Code cleanups and
simplifications and .text shrinkage.
"Kernel stack usage histogram" from Pasha Tatashin and Shakeel Butt. This
is a feature, it adds new feilds to /proc/vmstat such as
$ grep kstack /proc/vmstat
kstack_1k 3
kstack_2k 188
kstack_4k 11391
kstack_8k 243
kstack_16k 0
which tells us that 11391 processes used 4k of stack while none at all
used 16k. Useful for some system tuning things, but partivularly useful
for "the dynamic kernel stack project".
"kmemleak: support for percpu memory leak detect" from Pavel Tikhomirov.
Teaches kmemleak to detect leaksage of percpu memory.
"mm: memcg: page counters optimizations" from Roman Gushchin. "3
independent small optimizations of page counters".
"mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from David
Hildenbrand. Improves PTE/PMD splitlock detection, makes powerpc/8xx work
correctly by design rather than by accident.
"mm: remove arch_make_page_accessible()" from David Hildenbrand. Some
folio conversions which make arch_make_page_accessible() unneeded.
"mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David Finkel.
Cleans up and fixes our handling of the resetting of the cgroup/process
peak-memory-use detector.
"Make core VMA operations internal and testable" from Lorenzo Stoakes.
Rationalizaion and encapsulation of the VMA manipulation APIs. With a
view to better enable testing of the VMA functions, even from a
userspace-only harness.
"mm: zswap: fixes for global shrinker" from Takero Funaki. Fix issues in
the zswap global shrinker, resulting in improved performance.
"mm: print the promo watermark in zoneinfo" from Kaiyang Zhao. Fill in
some missing info in /proc/zoneinfo.
"mm: replace follow_page() by folio_walk" from David Hildenbrand. Code
cleanups and rationalizations (conversion to folio_walk()) resulting in
the removal of follow_page().
"improving dynamic zswap shrinker protection scheme" from Nhat Pham. Some
tuning to improve zswap's dynamic shrinker. Significant reductions in
swapin and improvements in performance are shown.
"mm: Fix several issues with unaccepted memory" from Kirill Shutemov.
Improvements to the new unaccepted memory feature,
"mm/mprotect: Fix dax puds" from Peter Xu. Implements mprotect on DAX
PUDs. This was missing, although nobody seems to have notied yet.
"Introduce a store type enum for the Maple tree" from Sidhartha Kumar.
Cleanups and modest performance improvements for the maple tree library
code.
"memcg: further decouple v1 code from v2" from Shakeel Butt. Move more
cgroup v1 remnants away from the v2 memcg code.
"memcg: initiate deprecation of v1 features" from Shakeel Butt. Adds
various warnings telling users that memcg v1 features are deprecated.
"mm: swap: mTHP swap allocator base on swap cluster order" from Chris Li.
Greatly improves the success rate of the mTHP swap allocation.
"mm: introduce numa_memblks" from Mike Rapoport. Moves various disparate
per-arch implementations of numa_memblk code into generic code.
"mm: batch free swaps for zap_pte_range()" from Barry Song. Greatly
improves the performance of munmap() of swap-filled ptes.
"support large folio swap-out and swap-in for shmem" from Baolin Wang.
With this series we no longer split shmem large folios into simgle-page
folios when swapping out shmem.
"mm/hugetlb: alloc/free gigantic folios" from Yu Zhao. Nice performance
improvements and code reductions for gigantic folios.
"support shmem mTHP collapse" from Baolin Wang. Adds support for
khugepaged's collapsing of shmem mTHP folios.
"mm: Optimize mseal checks" from Pedro Falcato. Fixes an mprotect()
performance regression due to the addition of mseal().
"Increase the number of bits available in page_type" from Matthew Wilcox.
Increases the number of bits available in page_type!
"Simplify the page flags a little" from Matthew Wilcox. Many legacy page
flags are now folio flags, so the page-based flags and their
accessors/mutators can be removed.
"mm: store zero pages to be swapped out in a bitmap" from Usama Arif. An
optimization which permits us to avoid writing/reading zero-filled zswap
pages to backing store.
"Avoid MAP_FIXED gap exposure" from Liam Howlett. Fixes a race window
which occurs when a MAP_FIXED operqtion is occurring during an unrelated
vma tree walk.
"mm: remove vma_merge()" from Lorenzo Stoakes. Major rotorooting of the
vma_merge() functionality, making ot cleaner, more testable and better
tested.
"misc fixups for DAMON {self,kunit} tests" from SeongJae Park. Minor
fixups of DAMON selftests and kunit tests.
"mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang. Code
cleanups and folio conversions.
"Shmem mTHP controls and stats improvements" from Ryan Roberts. Cleanups
for shmem controls and stats.
"mm: count the number of anonymous THPs per size" from Barry Song. Expose
additional anon THP stats to userspace for improved tuning.
"mm: finish isolate/putback_lru_page()" from Kefeng Wang: more folio
conversions and removal of now-unused page-based APIs.
"replace per-quota region priorities histogram buffer with per-context
one" from SeongJae Park. DAMON histogram rationalization.
"Docs/damon: update GitHub repo URLs and maintainer-profile" from SeongJae
Park. DAMON documentation updates.
"mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and improve
related doc and warn" from Jason Wang: fixes usage of page allocator
__GFP_NOFAIL and GFP_ATOMIC flags.
"mm: split underused THPs" from Yu Zhao. Improve THP=always policy - this
was overprovisioning THPs in sparsely accessed memory areas.
"zram: introduce custom comp backends API" frm Sergey Senozhatsky. Add
support for zram run-time compression algorithm tuning.
"mm: Care about shadow stack guard gap when getting an unmapped area" from
Mark Brown. Fix up the various arch_get_unmapped_area() implementations
to better respect guard areas.
"Improve mem_cgroup_iter()" from Kinsey Ho. Improve the reliability of
mem_cgroup_iter() and various code cleanups.
"mm: Support huge pfnmaps" from Peter Xu. Extends the usage of huge
pfnmap support.
"resource: Fix region_intersects() vs add_memory_driver_managed()" from
Huang Ying. Fix a bug in region_intersects() for systems with CXL memory.
"mm: hwpoison: two more poison recovery" from Kefeng Wang. Teaches a
couple more code paths to correctly recover from the encountering of
poisoned memry.
"mm: enable large folios swap-in support" from Barry Song. Support the
swapin of mTHP memory into appropriately-sized folios, rather than into
single-page folios.
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Merge tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
"Along with the usual shower of singleton patches, notable patch series
in this pull request are:
- "Align kvrealloc() with krealloc()" from Danilo Krummrich. Adds
consistency to the APIs and behaviour of these two core allocation
functions. This also simplifies/enables Rustification.
- "Some cleanups for shmem" from Baolin Wang. No functional changes -
mode code reuse, better function naming, logic simplifications.
- "mm: some small page fault cleanups" from Josef Bacik. No
functional changes - code cleanups only.
- "Various memory tiering fixes" from Zi Yan. A small fix and a
little cleanup.
- "mm/swap: remove boilerplate" from Yu Zhao. Code cleanups and
simplifications and .text shrinkage.
- "Kernel stack usage histogram" from Pasha Tatashin and Shakeel
Butt. This is a feature, it adds new feilds to /proc/vmstat such as
$ grep kstack /proc/vmstat
kstack_1k 3
kstack_2k 188
kstack_4k 11391
kstack_8k 243
kstack_16k 0
which tells us that 11391 processes used 4k of stack while none at
all used 16k. Useful for some system tuning things, but
partivularly useful for "the dynamic kernel stack project".
- "kmemleak: support for percpu memory leak detect" from Pavel
Tikhomirov. Teaches kmemleak to detect leaksage of percpu memory.
- "mm: memcg: page counters optimizations" from Roman Gushchin. "3
independent small optimizations of page counters".
- "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from
David Hildenbrand. Improves PTE/PMD splitlock detection, makes
powerpc/8xx work correctly by design rather than by accident.
- "mm: remove arch_make_page_accessible()" from David Hildenbrand.
Some folio conversions which make arch_make_page_accessible()
unneeded.
- "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David
Finkel. Cleans up and fixes our handling of the resetting of the
cgroup/process peak-memory-use detector.
- "Make core VMA operations internal and testable" from Lorenzo
Stoakes. Rationalizaion and encapsulation of the VMA manipulation
APIs. With a view to better enable testing of the VMA functions,
even from a userspace-only harness.
- "mm: zswap: fixes for global shrinker" from Takero Funaki. Fix
issues in the zswap global shrinker, resulting in improved
performance.
- "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao. Fill
in some missing info in /proc/zoneinfo.
- "mm: replace follow_page() by folio_walk" from David Hildenbrand.
Code cleanups and rationalizations (conversion to folio_walk())
resulting in the removal of follow_page().
- "improving dynamic zswap shrinker protection scheme" from Nhat
Pham. Some tuning to improve zswap's dynamic shrinker. Significant
reductions in swapin and improvements in performance are shown.
- "mm: Fix several issues with unaccepted memory" from Kirill
Shutemov. Improvements to the new unaccepted memory feature,
- "mm/mprotect: Fix dax puds" from Peter Xu. Implements mprotect on
DAX PUDs. This was missing, although nobody seems to have notied
yet.
- "Introduce a store type enum for the Maple tree" from Sidhartha
Kumar. Cleanups and modest performance improvements for the maple
tree library code.
- "memcg: further decouple v1 code from v2" from Shakeel Butt. Move
more cgroup v1 remnants away from the v2 memcg code.
- "memcg: initiate deprecation of v1 features" from Shakeel Butt.
Adds various warnings telling users that memcg v1 features are
deprecated.
- "mm: swap: mTHP swap allocator base on swap cluster order" from
Chris Li. Greatly improves the success rate of the mTHP swap
allocation.
- "mm: introduce numa_memblks" from Mike Rapoport. Moves various
disparate per-arch implementations of numa_memblk code into generic
code.
- "mm: batch free swaps for zap_pte_range()" from Barry Song. Greatly
improves the performance of munmap() of swap-filled ptes.
- "support large folio swap-out and swap-in for shmem" from Baolin
Wang. With this series we no longer split shmem large folios into
simgle-page folios when swapping out shmem.
- "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao. Nice
performance improvements and code reductions for gigantic folios.
- "support shmem mTHP collapse" from Baolin Wang. Adds support for
khugepaged's collapsing of shmem mTHP folios.
- "mm: Optimize mseal checks" from Pedro Falcato. Fixes an mprotect()
performance regression due to the addition of mseal().
- "Increase the number of bits available in page_type" from Matthew
Wilcox. Increases the number of bits available in page_type!
- "Simplify the page flags a little" from Matthew Wilcox. Many legacy
page flags are now folio flags, so the page-based flags and their
accessors/mutators can be removed.
- "mm: store zero pages to be swapped out in a bitmap" from Usama
Arif. An optimization which permits us to avoid writing/reading
zero-filled zswap pages to backing store.
- "Avoid MAP_FIXED gap exposure" from Liam Howlett. Fixes a race
window which occurs when a MAP_FIXED operqtion is occurring during
an unrelated vma tree walk.
- "mm: remove vma_merge()" from Lorenzo Stoakes. Major rotorooting of
the vma_merge() functionality, making ot cleaner, more testable and
better tested.
- "misc fixups for DAMON {self,kunit} tests" from SeongJae Park.
Minor fixups of DAMON selftests and kunit tests.
- "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang.
Code cleanups and folio conversions.
- "Shmem mTHP controls and stats improvements" from Ryan Roberts.
Cleanups for shmem controls and stats.
- "mm: count the number of anonymous THPs per size" from Barry Song.
Expose additional anon THP stats to userspace for improved tuning.
- "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more
folio conversions and removal of now-unused page-based APIs.
- "replace per-quota region priorities histogram buffer with
per-context one" from SeongJae Park. DAMON histogram
rationalization.
- "Docs/damon: update GitHub repo URLs and maintainer-profile" from
SeongJae Park. DAMON documentation updates.
- "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and
improve related doc and warn" from Jason Wang: fixes usage of page
allocator __GFP_NOFAIL and GFP_ATOMIC flags.
- "mm: split underused THPs" from Yu Zhao. Improve THP=always policy.
This was overprovisioning THPs in sparsely accessed memory areas.
- "zram: introduce custom comp backends API" frm Sergey Senozhatsky.
Add support for zram run-time compression algorithm tuning.
- "mm: Care about shadow stack guard gap when getting an unmapped
area" from Mark Brown. Fix up the various arch_get_unmapped_area()
implementations to better respect guard areas.
- "Improve mem_cgroup_iter()" from Kinsey Ho. Improve the reliability
of mem_cgroup_iter() and various code cleanups.
- "mm: Support huge pfnmaps" from Peter Xu. Extends the usage of huge
pfnmap support.
- "resource: Fix region_intersects() vs add_memory_driver_managed()"
from Huang Ying. Fix a bug in region_intersects() for systems with
CXL memory.
- "mm: hwpoison: two more poison recovery" from Kefeng Wang. Teaches
a couple more code paths to correctly recover from the encountering
of poisoned memry.
- "mm: enable large folios swap-in support" from Barry Song. Support
the swapin of mTHP memory into appropriately-sized folios, rather
than into single-page folios"
* tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (416 commits)
zram: free secondary algorithms names
uprobes: turn xol_area->pages[2] into xol_area->page
uprobes: introduce the global struct vm_special_mapping xol_mapping
Revert "uprobes: use vm_special_mapping close() functionality"
mm: support large folios swap-in for sync io devices
mm: add nr argument in mem_cgroup_swapin_uncharge_swap() helper to support large folios
mm: fix swap_read_folio_zeromap() for large folios with partial zeromap
mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries
set_memory: add __must_check to generic stubs
mm/vma: return the exact errno in vms_gather_munmap_vmas()
memcg: cleanup with !CONFIG_MEMCG_V1
mm/show_mem.c: report alloc tags in human readable units
mm: support poison recovery from copy_present_page()
mm: support poison recovery from do_cow_fault()
resource, kunit: add test case for region_intersects()
resource: make alloc_free_mem_region() works for iomem_resource
mm: z3fold: deprecate CONFIG_Z3FOLD
vfio/pci: implement huge_fault support
mm/arm64: support large pfn mappings
mm/x86: support large pfn mappings
...
- Implement the SCHED_DEADLINE server infrastructure - Daniel Bristot de Oliveira's
last major contribution to the kernel:
"SCHED_DEADLINE servers can help fixing starvation issues of low priority
tasks (e.g., SCHED_OTHER) when higher priority tasks monopolize CPU
cycles. Today we have RT Throttling; DEADLINE servers should be able to
replace and improve that."
(Daniel Bristot de Oliveira, Peter Zijlstra, Joel Fernandes,
Youssef Esmat, Huang Shijie)
- Preparatory changes for sched_ext integration:
- Use set_next_task(.first) where required
- Fix up set_next_task() implementations
- Clean up DL server vs. core sched
- Split up put_prev_task_balance()
- Rework pick_next_task()
- Combine the last put_prev_task() and the first set_next_task()
- Rework dl_server
- Add put_prev_task(.next)
(Peter Zijlstra, with a fix by Tejun Heo)
- Complete the EEVDF transition and refine EEVDF scheduling:
- Implement delayed dequeue
- Allow shorter slices to wakeup-preempt
- Use sched_attr::sched_runtime to set request/slice suggestion
- Document the new feature flags
- Remove unused and duplicate-functionality fields
- Simplify & unify pick_next_task_fair()
- Misc debuggability enhancements
(Peter Zijlstra, with fixes/cleanups by Dietmar Eggemann,
Valentin Schneider and Chuyi Zhou)
- Initialize the vruntime of a new task when it is first enqueued,
resulting in significant decrease in latency of newly woken tasks.
(Zhang Qiao)
- Introduce SM_IDLE and an idle re-entry fast-path in __schedule()
(K Prateek Nayak, Peter Zijlstra)
- Clean up and clarify the usage of Clean up usage of rt_task()
(Qais Yousef)
- Preempt SCHED_IDLE entities in strict cgroup hierarchies
(Tianchen Ding)
- Clarify the documentation of time units for deadline scheduler
parameters. (Christian Loehle)
- Remove the HZ_BW chicken-bit feature flag introduced a year ago,
the original change seems to be working fine.
(Phil Auld)
- Misc fixes and cleanups (Chen Yu, Dan Carpenter, Huang Shijie,
Peilin He, Qais Yousefm and Vincent Guittot)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2024-09-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
- Implement the SCHED_DEADLINE server infrastructure - Daniel Bristot
de Oliveira's last major contribution to the kernel:
"SCHED_DEADLINE servers can help fixing starvation issues of low
priority tasks (e.g., SCHED_OTHER) when higher priority tasks
monopolize CPU cycles. Today we have RT Throttling; DEADLINE
servers should be able to replace and improve that."
(Daniel Bristot de Oliveira, Peter Zijlstra, Joel Fernandes, Youssef
Esmat, Huang Shijie)
- Preparatory changes for sched_ext integration:
- Use set_next_task(.first) where required
- Fix up set_next_task() implementations
- Clean up DL server vs. core sched
- Split up put_prev_task_balance()
- Rework pick_next_task()
- Combine the last put_prev_task() and the first set_next_task()
- Rework dl_server
- Add put_prev_task(.next)
(Peter Zijlstra, with a fix by Tejun Heo)
- Complete the EEVDF transition and refine EEVDF scheduling:
- Implement delayed dequeue
- Allow shorter slices to wakeup-preempt
- Use sched_attr::sched_runtime to set request/slice suggestion
- Document the new feature flags
- Remove unused and duplicate-functionality fields
- Simplify & unify pick_next_task_fair()
- Misc debuggability enhancements
(Peter Zijlstra, with fixes/cleanups by Dietmar Eggemann, Valentin
Schneider and Chuyi Zhou)
- Initialize the vruntime of a new task when it is first enqueued,
resulting in significant decrease in latency of newly woken tasks
(Zhang Qiao)
- Introduce SM_IDLE and an idle re-entry fast-path in __schedule()
(K Prateek Nayak, Peter Zijlstra)
- Clean up and clarify the usage of Clean up usage of rt_task()
(Qais Yousef)
- Preempt SCHED_IDLE entities in strict cgroup hierarchies
(Tianchen Ding)
- Clarify the documentation of time units for deadline scheduler
parameters (Christian Loehle)
- Remove the HZ_BW chicken-bit feature flag introduced a year ago,
the original change seems to be working fine (Phil Auld)
- Misc fixes and cleanups (Chen Yu, Dan Carpenter, Huang Shijie,
Peilin He, Qais Yousefm and Vincent Guittot)
* tag 'sched-core-2024-09-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits)
sched/cpufreq: Use NSEC_PER_MSEC for deadline task
cpufreq/cppc: Use NSEC_PER_MSEC for deadline task
sched/deadline: Clarify nanoseconds in uapi
sched/deadline: Convert schedtool example to chrt
sched/debug: Fix the runnable tasks output
sched: Fix sched_delayed vs sched_core
kernel/sched: Fix util_est accounting for DELAY_DEQUEUE
kthread: Fix task state in kthread worker if being frozen
sched/pelt: Use rq_clock_task() for hw_pressure
sched/fair: Move effective_cpu_util() and effective_cpu_util() in fair.c
sched/core: Introduce SM_IDLE and an idle re-entry fast-path in __schedule()
sched: Add put_prev_task(.next)
sched: Rework dl_server
sched: Combine the last put_prev_task() and the first set_next_task()
sched: Rework pick_next_task()
sched: Split up put_prev_task_balance()
sched: Clean up DL server vs core sched
sched: Fixup set_next_task() implementations
sched: Use set_next_task(.first) where required
sched/fair: Properly deactivate sched_delayed task upon class change
...
The current assumption is that a large folio can only be split into
order-0 folios. That is not the case for hugeTLB demotion, nor for THP
split: see commit c010d47f10 ("mm: thp: split huge page to any lower
order pages").
When a large folio is split into ones of a lower non-zero order, only the
new head pages should be tagged. Tagging tail pages can cause imbalanced
"calls" counters, since only head pages are untagged by pgalloc_tag_sub()
and the "calls" counts on tail pages are leaked, e.g.,
# echo 2048kB >/sys/kernel/mm/hugepages/hugepages-1048576kB/demote_size
# echo 700 >/sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages
# time echo 700 >/sys/kernel/mm/hugepages/hugepages-1048576kB/demote
# echo 0 >/sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages
# grep alloc_gigantic_folio /proc/allocinfo
Before this patch:
0 549427200 mm/hugetlb.c:1549 func:alloc_gigantic_folio
real 0m2.057s
user 0m0.000s
sys 0m2.051s
After this patch:
0 0 mm/hugetlb.c:1549 func:alloc_gigantic_folio
real 0m1.711s
user 0m0.000s
sys 0m1.704s
Not tagging tail pages also improves the splitting time, e.g., by about
15% when demoting 1GB hugeTLB folios to 2MB ones, as shown above.
Link: https://lkml.kernel.org/r/20240906042108.1150526-2-yuzhao@google.com
Fixes: be25d1d4e8 ("mm: create new codetag references during page splitting")
Signed-off-by: Yu Zhao <yuzhao@google.com>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
PGFREE is currently updated in two code paths:
- __free_pages_ok(): for pages freed to the buddy allocator.
- free_unref_page_commit(): for pages freed to the pcplists.
Before commit df1acc8569 ("mm/page_alloc: avoid conflating IRQs disabled
with zone->lock"), free_unref_page_commit() used to fallback to freeing
isolated pages directly to the buddy allocator through free_one_page().
This was done _after_ updating PGFREE, so the counter was correctly
updated.
However, that commit moved the fallback logic to its callers (now called
free_unref_page() and free_unref_folios()), so PGFREE was no longer
updated in this fallback case.
Now that the code has developed, there are more cases in free_unref_page()
and free_unref_folios() where we fallback to calling free_one_page() (e.g.
!pcp_allowed_order(), pcp_spin_trylock() fails). These cases also miss
updating PGFREE.
To make sure PGFREE is updated in all cases where pages are freed to the
buddy allocator, move the update down the stack to free_one_page().
This was noticed through code inspection, although it should be noticeable
at runtime (at least with some workloads).
Link: https://lkml.kernel.org/r/20240904205419.821776-1-yosryahmed@google.com
Fixes: df1acc8569 ("mm/page_alloc: avoid conflating IRQs disabled with zone->lock")
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When page del from buddy and need expand, it will account free_pages in
zone's migratetype.
The current way is to subtract the page number of the current order when
deleting, and then add it back when expanding.
This is unnecessary, as when migrating the same type, we can directly
record the difference between the high-order pages and the expand added,
and then subtract it directly.
This patch merge that, only when del and expand done, then account
free_pages.
Link: https://lkml.kernel.org/r/20240826064048.187790-1-link@vivo.com
Signed-off-by: Huan Yang <link@vivo.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Currently folio->_deferred_list is used to keep track of partially_mapped
folios that are going to be split under memory pressure. In the next
patch, all THPs that are faulted in and collapsed by khugepaged are also
going to be tracked using _deferred_list.
This patch introduces a pageflag to be able to distinguish between
partially mapped folios and others in the deferred_list at split time in
deferred_split_scan. Its needed as __folio_remove_rmap decrements
_mapcount, _large_mapcount and _entire_mapcount, hence it won't be
possible to distinguish between partially mapped folios and others in
deferred_split_scan.
Eventhough it introduces an extra flag to track if the folio is partially
mapped, there is no functional change intended with this patch and the
flag is not useful in this patch itself, it will become useful in the next
patch when _deferred_list has non partially mapped folios.
Link: https://lkml.kernel.org/r/20240830100438.3623486-5-usamaarif642@gmail.com
Signed-off-by: Usama Arif <usamaarif642@gmail.com>
Cc: Alexander Zhu <alexlzhu@fb.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Shuang Zhai <zhais@google.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Shuang Zhai <szhai2@cs.rochester.edu>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Three points for this change:
1. We should consolidate all warnings in one place. Currently, the
order > 1 warning is in the hotpath, while others are in less
likely scenarios. Moving all warnings to the slowpath will reduce
the overhead for order > 1 and increase the visibility of other
warnings.
2. We currently have two warnings for order: one for order > 1 in
the hotpath and another for order > costly_order in the laziest
path. I suggest standardizing on order > 1 since it's been in
use for a long time.
3. We don't need to check for __GFP_NOWARN in this case. __GFP_NOWARN
is meant to suppress allocation failure reports, but here we're
dealing with bug detection, not allocation failures. So replace
WARN_ON_ONCE_GFP by WARN_ON_ONCE.
[v-songbaohua@oppo.com: also update the doc for __GFP_NOFAIL with order > 1]
Link: https://lkml.kernel.org/r/20240903223935.1697-1-21cnbao@gmail.com
Link: https://lkml.kernel.org/r/20240830202823.21478-4-21cnbao@gmail.com
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: David Rientjes <rientjes@google.com>
Cc: "Eugenio Pérez" <eperezma@redhat.com>
Cc: Hailong.Liu <hailong.liu@oppo.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Xie Yongji <xieyongji@bytedance.com>
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Cc: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm: count the number of anonymous THPs per size", v4.
Knowing the number of transparent anon THPs in the system is crucial
for performance analysis. It helps in understanding the ratio and
distribution of THPs versus small folios throughout the system.
Additionally, partial unmapping by userspace can lead to significant waste
of THPs over time and increase memory reclamation pressure. We need this
information for comprehensive system tuning.
This patch (of 2):
Let's track for each anonymous THP size, how many of them are currently
allocated. We'll track the complete lifespan of an anon THP, starting
when it becomes an anon THP ("large anon folio") (->mapping gets set),
until it gets freed (->mapping gets cleared).
Introduce a new "nr_anon" counter per THP size and adjust the
corresponding counter in the following cases:
* We allocate a new THP and call folio_add_new_anon_rmap() to map
it the first time and turn it into an anon THP.
* We split an anon THP into multiple smaller ones.
* We migrate an anon THP, when we prepare the destination.
* We free an anon THP back to the buddy.
Note that AnonPages in /proc/meminfo currently tracks the total number of
*mapped* anonymous *pages*, and therefore has slightly different
semantics. In the future, we might also want to track "nr_anon_mapped"
for each THP size, which might be helpful when comparing it to the number
of allocated anon THPs (long-term pinning, stuck in swapcache, memory
leaks, ...).
Further note that for now, we only track anon THPs after they got their
->mapping set, for example via folio_add_new_anon_rmap(). If we would
allocate some in the swapcache, they will only show up in the statistics
for now after they have been mapped to user space the first time, where we
call folio_add_new_anon_rmap().
[akpm@linux-foundation.org: documentation fixups, per David]
Link: https://lkml.kernel.org/r/3e8add35-e26b-443b-8a04-1078f4bc78f6@redhat.com
Link: https://lkml.kernel.org/r/20240824010441.21308-1-21cnbao@gmail.com
Link: https://lkml.kernel.org/r/20240824010441.21308-2-21cnbao@gmail.com
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Chuanhua Han <hanchuanhua@oppo.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuai Yuan <yuanshuai@oppo.com>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm/hugetlb: alloc/free gigantic folios", v2.
Use __GFP_COMP for gigantic folios can greatly reduce not only the amount
of code but also the allocation and free time.
Approximate LOC to mm/hugetlb.c: +60, -240
Allocate and free 500 1GB hugeTLB memory without HVO by:
time echo 500 >/sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages
time echo 0 >/sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages
Before After
Alloc ~13s ~10s
Free ~15s <1s
The above magnitude generally holds for multiple x86 and arm64 CPU
models.
Perf profile before:
Alloc
- 99.99% alloc_pool_huge_folio
- __alloc_fresh_hugetlb_folio
- 83.23% alloc_contig_pages_noprof
- 47.46% alloc_contig_range_noprof
- 20.96% isolate_freepages_range
16.10% split_page
- 14.10% start_isolate_page_range
- 12.02% undo_isolate_page_range
Free
- update_and_free_pages_bulk
- 87.71% free_contig_range
- 76.02% free_unref_page
- 41.30% free_unref_page_commit
- 32.58% free_pcppages_bulk
- 24.75% __free_one_page
13.96% _raw_spin_trylock
12.27% __update_and_free_hugetlb_folio
Perf profile after:
Alloc
- 99.99% alloc_pool_huge_folio
alloc_gigantic_folio
- alloc_contig_pages_noprof
- 59.15% alloc_contig_range_noprof
- 20.72% start_isolate_page_range
20.64% prep_new_page
- 17.13% undo_isolate_page_range
Free
- update_and_free_pages_bulk
- __folio_put
- __free_pages_ok
7.46% free_tail_page_prepare
- 1.97% free_one_page
1.86% __free_one_page
This patch (of 3):
Support __GFP_COMP in alloc_contig_range(). When the flag is set, upon
success the function returns a large folio prepared by prep_new_page(),
rather than a range of order-0 pages prepared by split_free_pages() (which
is renamed from split_map_pages()).
alloc_contig_range() can be used to allocate folios larger than
MAX_PAGE_ORDER, e.g., gigantic hugeTLB folios. So on the free path,
free_one_page() needs to handle that by split_large_buddy().
[akpm@linux-foundation.org: fix folio_alloc_gigantic_noprof() WARN expression, per Yu Liao]
Link: https://lkml.kernel.org/r/20240814035451.773331-1-yuzhao@google.com
Link: https://lkml.kernel.org/r/20240814035451.773331-2-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Acked-by: Zi Yan <ziy@nvidia.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Frank van der Linden <fvdl@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>