swap_cache_info are not statistics that could be easily used to tune
system performance because they are not easily accessile. Also they can't
provide really useful info when OOM occurs. Remove these statistics can
also help mitigate unneeded global swap_cache_info cacheline contention.
Link: https://lkml.kernel.org/r/20220608144031.829-4-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
si->inuse_pages could still be accessed concurrently now. The plain reads
outside si->lock critical section, i.e. swap_show and si_swapinfo, which
results in data races. READ_ONCE and WRITE_ONCE is used to fix such data
races. Note these data races should be ok because they're just used for
showing swap info.
[linmiaohe@huawei.com: use WRITE_ONCE to pair with READ_ONCE]
Link: https://lkml.kernel.org/r/20220625093346.48894-2-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20220608144031.829-3-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
__find_vmap_area() finds a "vmap_area" based on passed address. It scan
the specific "vmap_area_root" rb-tree. Extend the function with one extra
argument, so any tree can be specified where the search has to be done.
There is no functional change as a result of this patch.
Link: https://lkml.kernel.org/r/20220607093449.3100-5-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
A vmap_area can travel between different places. For example
attached/detached to/from different rb-trees. In order to prevent fancy
bugs, initialize a VA's list node after it is removed from the list, so it
pairs with VA's rb_node which is also initialized.
There is no functional change as a result of this patch.
Link: https://lkml.kernel.org/r/20220607093449.3100-4-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
It implies that __alloc_vmap_area() allocates only from the global vmap
space, therefore a list-head and rb-tree, which represent a free vmap
space, are not passed as parameters to this function and are accessed
directly from this function.
Extend the __alloc_vmap_area() and other dependent functions to have a
possibility to allocate from different trees making an interface common
and not specific.
There is no functional change as a result of this patch.
Link: https://lkml.kernel.org/r/20220607093449.3100-3-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Reduce a vmalloc internal lock contention preparation work".
This small serias is preparation work to implement per-cpu vmalloc
allocation in order to reduce a high internal lock contention. This
series does not introduce any functional changes, it is only about
preparation.
This patch (of 5):
Currently link_va() and unlik_va(), in order to figure out a tree type,
compares a passed root value with a global free_vmap_area_root variable to
distinguish the augmented rb-tree from a regular one. It is hard coded
since such functions can manipulate only with specific
"free_vmap_area_root" tree that represents a global free vmap space.
Make it common by introducing "_augment" versions of both internal
functions, so it is possible to deal with different trees.
There is no functional change as a result of this patch.
Link: https://lkml.kernel.org/r/20220607093449.3100-1-urezki@gmail.com
Link: https://lkml.kernel.org/r/20220607093449.3100-2-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add a scan interface which allows to trigger scanning of a particular
shrinker and specify memcg and numa node. It's useful for testing,
debugging and profiling of a specific scan_objects() callback. Unlike
alternatives (creating a real memory pressure and dropping caches via
/proc/sys/vm/drop_caches) this interface allows to interact with only one
shrinker at once. Also, if a shrinker is misreporting the number of
objects (as some do), it doesn't affect scanning.
[roman.gushchin@linux.dev: improve typing, fix arg count checking]
Link: https://lkml.kernel.org/r/YpgKttTowT22mKPQ@carbon
[akpm@linux-foundation.org: fix arg count checking]
Link: https://lkml.kernel.org/r/20220601032227.4076670-7-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Muchun Song <songmuchun@bytedance.com>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Currently shrinkers are anonymous objects. For debugging purposes they
can be identified by count/scan function names, but it's not always
useful: e.g. for superblock's shrinkers it's nice to have at least an
idea of to which superblock the shrinker belongs.
This commit adds names to shrinkers. register_shrinker() and
prealloc_shrinker() functions are extended to take a format and arguments
to master a name.
In some cases it's not possible to determine a good name at the time when
a shrinker is allocated. For such cases shrinker_debugfs_rename() is
provided.
The expected format is:
<subsystem>-<shrinker_type>[:<instance>]-<id>
For some shrinkers an instance can be encoded as (MAJOR:MINOR) pair.
After this change the shrinker debugfs directory looks like:
$ cd /sys/kernel/debug/shrinker/
$ ls
dquota-cache-16 sb-devpts-28 sb-proc-47 sb-tmpfs-42
mm-shadow-18 sb-devtmpfs-5 sb-proc-48 sb-tmpfs-43
mm-zspool:zram0-34 sb-hugetlbfs-17 sb-pstore-31 sb-tmpfs-44
rcu-kfree-0 sb-hugetlbfs-33 sb-rootfs-2 sb-tmpfs-49
sb-aio-20 sb-iomem-12 sb-securityfs-6 sb-tracefs-13
sb-anon_inodefs-15 sb-mqueue-21 sb-selinuxfs-22 sb-xfs:vda1-36
sb-bdev-3 sb-nsfs-4 sb-sockfs-8 sb-zsmalloc-19
sb-bpf-32 sb-pipefs-14 sb-sysfs-26 thp-deferred_split-10
sb-btrfs:vda2-24 sb-proc-25 sb-tmpfs-1 thp-zero-9
sb-cgroup2-30 sb-proc-39 sb-tmpfs-27 xfs-buf:vda1-37
sb-configfs-23 sb-proc-41 sb-tmpfs-29 xfs-inodegc:vda1-38
sb-dax-11 sb-proc-45 sb-tmpfs-35
sb-debugfs-7 sb-proc-46 sb-tmpfs-40
[roman.gushchin@linux.dev: fix build warnings]
Link: https://lkml.kernel.org/r/Yr+ZTnLb9lJk6fJO@castle
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lkml.kernel.org/r/20220601032227.4076670-4-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit introduces the /sys/kernel/debug/shrinker debugfs interface
which provides an ability to observe the state of individual kernel memory
shrinkers.
Because the feature adds some memory overhead (which shouldn't be large
unless there is a huge amount of registered shrinkers), it's guarded by a
config option (enabled by default).
This commit introduces the "count" interface for each shrinker registered
in the system.
The output is in the following format:
<cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>...
<cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>...
...
To reduce the size of output on machines with many thousands cgroups, if
the total number of objects on all nodes is 0, the line is omitted.
If the shrinker is not memcg-aware or CONFIG_MEMCG is off, 0 is printed as
cgroup inode id. If the shrinker is not numa-aware, 0's are printed for
all nodes except the first one.
This commit gives debugfs entries simple numeric names, which are not very
convenient. The following commit in the series will provide shrinkers
with more meaningful names.
[akpm@linux-foundation.org: remove WARN_ON_ONCE(), per Roman]
Reported-by: syzbot+300d27c79fe6d4cbcc39@syzkaller.appspotmail.com
Link: https://lkml.kernel.org/r/20220601032227.4076670-3-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Acked-by: Muchun Song <songmuchun@bytedance.com>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Hillf Danton <hdanton@sina.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm: introduce shrinker debugfs interface", v5.
The only existing debugging mechanism is a couple of tracepoints in
do_shrink_slab(): mm_shrink_slab_start and mm_shrink_slab_end. They
aren't covering everything though: shrinkers which report 0 objects will
never show up, there is no support for memcg-aware shrinkers. Shrinkers
are identified by their scan function, which is not always enough (e.g.
hard to guess which super block's shrinker it is having only
"super_cache_scan").
To provide a better visibility and debug options for memory shrinkers this
patchset introduces a /sys/kernel/debug/shrinker interface, to some extent
similar to /sys/kernel/slab.
For each shrinker registered in the system a directory is created. As
now, the directory will contain only a "scan" file, which allows to get
the number of managed objects for each memory cgroup (for memcg-aware
shrinkers) and each numa node (for numa-aware shrinkers on a numa
machine). Other interfaces might be added in the future.
To make debugging more pleasant, the patchset also names all shrinkers, so
that debugfs entries can have meaningful names.
This patch (of 5):
Shrinker debugfs requires a way to represent memory cgroups without using
full paths, both for displaying information and getting input from a user.
Cgroup inode number is a perfect way, already used by bpf.
This commit adds a couple of helper functions which will be used to handle
memcg-aware shrinkers.
Link: https://lkml.kernel.org/r/20220601032227.4076670-1-roman.gushchin@linux.dev
Link: https://lkml.kernel.org/r/20220601032227.4076670-2-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Muchun Song <songmuchun@bytedance.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When user specified more nodes than supported, get_nodes will access nmask
array out of bounds.
Link: https://lkml.kernel.org/r/20220601093211.2970565-1-tianyu.li@arm.com
Fixes: e130242dc3 ("mm: simplify compat numa syscalls")
Signed-off-by: Tianyu Li <tianyu.li@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
There is no need to update the hugetlb access flags after just setting the
hugetlb page table entry by set_huge_pte_at(), since the page table entry
value has no changes.
Thus remove the unnecessary huge_ptep_set_access_flags() in
hugetlb_mcopy_atomic_pte().
Link: https://lkml.kernel.org/r/f3e28b897b53a69967a8b98a6fdcda3be80c9229.1653616175.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
HW_TAGS KASAN skips zeroing page_alloc allocations backing vmalloc
mappings via __GFP_SKIP_ZERO. Instead, these pages are zeroed via
kasan_unpoison_vmalloc() by passing the KASAN_VMALLOC_INIT flag.
The problem is that __kasan_unpoison_vmalloc() does not zero pages when
either kasan_vmalloc_enabled() or is_vmalloc_or_module_addr() fail.
Thus:
1. Change __vmalloc_node_range() to only set KASAN_VMALLOC_INIT when
__GFP_SKIP_ZERO is set.
2. Change __kasan_unpoison_vmalloc() to always zero pages when the
KASAN_VMALLOC_INIT flag is set.
3. Add WARN_ON() asserts to check that KASAN_VMALLOC_INIT cannot be set
in other early return paths of __kasan_unpoison_vmalloc().
Also clean up the comment in __kasan_unpoison_vmalloc.
Link: https://lkml.kernel.org/r/4bc503537efdc539ffc3f461c1b70162eea31cf6.1654798516.git.andreyknvl@google.com
Fixes: 23689e91fb ("kasan, vmalloc: add vmalloc tagging for HW_TAGS")
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add a clear_highpage_kasan_tagged() helper that does clear_highpage() on a
page potentially tagged by KASAN.
This helper is used by the following patch.
Link: https://lkml.kernel.org/r/4471979b46b2c487787ddcd08b9dc5fedd1b6ffd.1654798516.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Rename kernel_init_free_pages() to kernel_init_pages(). This function is
not only used for free pages but also for pages that were just allocated.
Link: https://lkml.kernel.org/r/1ecaffc0a9c1404d4d7cf52efe0b2dc8a0c681d8.1654798516.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit adds 'damon_reclaim_' prefix to 'enabled_store()', so that we
can distinguish it easily from the stack trace using 'faddr2line.sh' like
tools.
Link: https://lkml.kernel.org/r/20220606182310.48781-7-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
DAMON_RECLAIM's 'enabled' parameter store callback ('enabled_store()')
schedules the parameter check timer ('damon_reclaim_timer') if the
parameter is set as 'Y'. Then, the timer schedules itself to check if
user has set the parameter as 'N'. It's unnecessarily complex.
This commit makes it simpler by making the parameter store callback to
schedule the timer regardless of the parameter value and disabling the
timer's self scheduling.
Link: https://lkml.kernel.org/r/20220606182310.48781-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
DAMON sysfs interface's DAMON context building and its online parameter
update have duplicated code. This commit removes the duplicate.
Link: https://lkml.kernel.org/r/20220606182310.48781-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
DAMON_RECLAIM's handling of 'commit_inputs' parameter is duplicated in
'after_aggregation()' and 'after_wmarks_check()' callbacks. This commit
deduplicates the code for better maintenance.
Link: https://lkml.kernel.org/r/20220606182310.48781-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The function for knowing if given monitoring context's targets will have
pid or not is defined and used in dbgfs only. However, the logic is also
needed for sysfs. This commit moves the code to damon.h and makes both
dbgfs and sysfs to use it.
Link: https://lkml.kernel.org/r/20220606182310.48781-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
__migration_entry_wait and migration_entry_wait_on_locked assume pte is
always mapped from caller. But this is not the case when it's called from
migration_entry_wait_huge and follow_huge_pmd. Add a hugetlbfs variant
that calls hugetlb_migration_entry_wait(ptep == NULL) to fix this issue.
Link: https://lkml.kernel.org/r/20220530113016.16663-5-linmiaohe@huawei.com
Fixes: 30dad30922 ("mm: migration: add migrate_entry_wait_huge()")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We might fail to isolate huge page due to e.g. the page is under
migration which cleared HPageMigratable. We should return errno in this
case rather than always return 1 which could confuse the user, i.e. the
caller might think all of the memory is migrated while the hugetlb page is
left behind. We make the prototype of isolate_huge_page consistent with
isolate_lru_page as suggested by Huang Ying and rename isolate_huge_page
to isolate_hugetlb as suggested by Muchun to improve the readability.
Link: https://lkml.kernel.org/r/20220530113016.16663-4-linmiaohe@huawei.com
Fixes: e8db67eb0d ("mm: migrate: move_pages() supports thp migration")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Suggested-by: Huang Ying <ying.huang@intel.com>
Reported-by: kernel test robot <lkp@intel.com> (build error)
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When non-lru movable page was freed from under us, __ClearPageMovable must
have been done. So we can remove unneeded lock page and PageMovable check
here. Also free_pages_prepare() will clear PG_isolated for us, so we can
further remove ClearPageIsolated as suggested by David.
Link: https://lkml.kernel.org/r/20220530113016.16663-3-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
IIUC page_vma_mapped_walk() checks if the vma is possibly huge PMD mapped
with transparent_hugepage_active() and "pvmw->nr_pages >= HPAGE_PMD_NR".
Actually pvmw->nr_pages is returned by compound_nr() or folio_nr_pages(),
so the page should be THP as long as "pvmw->nr_pages >= HPAGE_PMD_NR".
And it is guaranteed THP is allocated for valid VMA in the first place.
But it may be not PMD mapped if the VMA is file VMA and it is not properly
aligned. The transhuge_vma_suitable() is used to do such check, so
replace transparent_hugepage_active() to it, which is too heavy and
overkilling.
Link: https://lkml.kernel.org/r/20220513191705.457775-1-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Currently the implementation will split the PUD when a fallback is taken
inside the create_huge_pud function. This isn't where it should be done:
the splitting should be done in wp_huge_pud, just like it's done for PMDs.
Reason being that if a callback is taken during create, there is no PUD
yet so nothing to split, whereas if a fallback is taken when encountering
a write protection fault there is something to split.
It looks like this was the original intention with the commit where the
splitting was introduced, but somehow it got moved to the wrong place
between v1 and v2 of the patch series. Rebase mistake perhaps.
Link: https://lkml.kernel.org/r/6f48d622eb8bce1ae5dd75327b0b73894a2ec407.camel@amazon.com
Fixes: 327e9fd489 ("mm: Split huge pages on write-notify or COW")
Signed-off-by: James Gowans <jgowans@amazon.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Higher order allocations for vmemmap pages from buddy allocator must be
able to be treated as indepdenent small pages as they can be freed
individually by the caller. There is no problem for higher order vmemmap
pages allocated at boot time since each individual small page will be
initialized at boot time. However, it will be an issue for memory hotplug
case since those higher order vmemmap pages are allocated from buddy
allocator without initializing each individual small page's refcount. The
system will panic in put_page_testzero() when CONFIG_DEBUG_VM is enabled
if the vmemmap page is freed.
Link: https://lkml.kernel.org/r/20220620023019.94257-1-songmuchun@bytedance.com
Fixes: d8d55f5616 ("mm: sparsemem: use page table lock to protect kernel pmd operations")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The huge_ptep_set_access_flags() can not make the huge pte old according
to the discussion [1], that means we will always mornitor the young state
of the hugetlb though we stopped accessing the hugetlb, as a result DAMON
will get inaccurate accessing statistics.
So changing to use set_huge_pte_at() to make the huge pte old to fix this
issue.
[1] https://lore.kernel.org/all/Yqy97gXI4Nqb7dYo@arm.com/
Link: https://lkml.kernel.org/r/1655692482-28797-1-git-send-email-baolin.wang@linux.alibaba.com
Fixes: 49f4203aae ("mm/damon: add access checking for hugetlb pages")
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When fallocate() is used on a shmem file, the pages we allocate can end up
with !PageUptodate.
Since UFFDIO_CONTINUE tries to find the existing page the user wants to
map with SGP_READ, we would fail to find such a page, since
shmem_getpage_gfp returns with a "NULL" pagep for SGP_READ if it discovers
!PageUptodate. As a result, UFFDIO_CONTINUE returns -EFAULT, as it would
do if the page wasn't found in the page cache at all.
This isn't the intended behavior. UFFDIO_CONTINUE is just trying to find
if a page exists, and doesn't care whether it still needs to be cleared or
not. So, instead of SGP_READ, pass in SGP_NOALLOC. This is the same,
except for one critical difference: in the !PageUptodate case, SGP_NOALLOC
will clear the page and then return it. With this change, UFFDIO_CONTINUE
works properly (succeeds) on a shmem file which has been fallocated, but
otherwise not modified.
Link: https://lkml.kernel.org/r/20220610173812.1768919-1-axelrasmussen@google.com
Fixes: 153132571f ("userfaultfd/shmem: support UFFDIO_CONTINUE for shmem")
Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
Acked-by: Peter Xu <peterx@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
A recent commit factored out a series of annoying (unsigned long) casts
into a single variable declaration, but made the pointer type a
`uintptr_t` rather than the usual `unsigned long`. This patch changes it
to be the integer type more typically used by the kernel to represent
addresses.
Fixes: 35fb9ae4aa ("usercopy: Cast pointer to an integer once")
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220616143617.449094-1-Jason@zx2c4.com
The worst case is that the new memory range overlaps all existing
regions, which requires type->cnt + 1 empty struct memblock_region slots in
the type->regions array.
So if type->cnt + 1 + type->cnt is less than type->max, we can insert
regions directly rather than calculate the needed amount before the
insertion.
And becase of merge operation in the end of function, tpye->cnt will
increase slowly for many cases.
This change allows to avoid unnecessary repeat of memblock ranges traversal
for many cases when adding new memory range.
Signed-off-by: Jinyu Tang <tjytimi@163.com>
[rppt: massaged comment and changelog text]
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
By passing ->read_folio to filemap_read_folio(), we can use
filemap_read_folio() in do_read_cache_folio().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
If the call to filler() returns AOP_TRUNCATED_PAGE, we need to
retry the page cache lookup.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
No functionality change intended; this simply moves code around to
disentangle the function a little.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
All callers of find_get_pages_range(), pagevec_lookup_range() and
pagevec_lookup() have now been removed.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org>
This is a straightforward conversion.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Change the guts of check_move_unevictable_pages() over to use folios
and add check_move_unevictable_pages() as a wrapper.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org>
This is the equivalent of find_get_pages() but fills a folio_batch
instead of an array of pages.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org>
These functions have no more users, so delete them.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Remove the last caller of add_to_page_cache()
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
If the last folio in a file is split as a result of truncation,
we simply clear the dirty bits for the pages we're discarding.
That causes NR_FILE_DIRTY (among other counters) to be thrown off
and eventually Linux will hang in balance_dirty_pages_ratelimited()
Reported-by: Dave Chinner <dchinner@redhat.com>
Tested-by: Dave Chinner <dchinner@redhat.com>
Tested-by: Darrick J. Wong <djwong@kernel.org>
Fixes: d68eccad37 ("mm/filemap: Allow large folios to be added to the page cache")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
All architecture-independent users of virt_to_bus() and bus_to_virt()
have been fixed to use the dma mapping interfaces or have been
removed now. This means the definitions on most architectures, and the
CONFIG_VIRT_TO_BUS symbol are now obsolete and can be removed.
The only exceptions to this are a few network and scsi drivers for m68k
Amiga and VME machines and ppc32 Macintosh. These drivers work correctly
with the old interfaces and are probably not worth changing.
On alpha and parisc, virt_to_bus() were still used in asm/floppy.h.
alpha can use isa_virt_to_bus() like x86 does, and parisc can just
open-code the virt_to_phys() here, as this is architecture specific
code.
I tried updating the bus-virt-phys-mapping.rst documentation, which
started as an email from Linus to explain some details of the Linux-2.0
driver interfaces. The bits about virt_to_bus() were declared obsolete
backin 2000, and the rest is not all that relevant any more, so in the
end I just decided to remove the file completely.
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: Helge Deller <deller@gmx.de> # parisc
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
so it will be consistent with code mm directory and with
Documentation/admin-guide/mm and won't be confused with virtual machines.
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Tested-by: Ira Weiny <ira.weiny@intel.com>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Acked-by: Wu XiangCheng <bobwxc@email.cn>
Add special hook for architecture to verify addr, size or prot
when ioremap() or iounmap(), which will make the generic ioremap
more useful.
ioremap_allowed() return a bool,
- true means continue to remap
- false means skip remap and return directly
iounmap_allowed() return a bool,
- true means continue to vunmap
- false code means skip vunmap and return directly
Meanwhile, only vunmap the address when it is in vmalloc area
as the generic ioremap only returns vmalloc addresses.
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Baoquan He <bhe@redhat.com>
Link: https://lore.kernel.org/r/20220607125027.44946-5-wangkefeng.wang@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>
Show physical address of each ioremap in /proc/vmallocinfo.
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Link: https://lore.kernel.org/r/20220607125027.44946-4-wangkefeng.wang@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>
Use more meaningful and sensible naming phys_addr
instead addr in ioremap_prot().
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220610092255.32445-1-wangkefeng.wang@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>
Fixes for post-5.18 changes:
- fix for a damon boot hang, from SeongJae
- fix for a kfence warning splat, from Jason Donenfeld
- fix for zero-pfn pinning, from Alex Williamson
- fix for fallocate hole punch clearing, from Mike Kravetz
Fixes pre-5.18 material:
- fix for a performance regression, from Marcelo
- fix for a hwpoisining BUG from zhenwei pi
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Merge tag 'mm-hotfixes-stable-2022-06-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull hotfixes from Andrew Morton:
"Minor things, mainly - mailmap updates, MAINTAINERS updates, etc.
Fixes for this merge window:
- fix for a damon boot hang, from SeongJae
- fix for a kfence warning splat, from Jason Donenfeld
- fix for zero-pfn pinning, from Alex Williamson
- fix for fallocate hole punch clearing, from Mike Kravetz
Fixes for previous releases:
- fix for a performance regression, from Marcelo
- fix for a hwpoisining BUG from zhenwei pi"
* tag 'mm-hotfixes-stable-2022-06-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
mailmap: add entry for Christian Marangi
mm/memory-failure: disable unpoison once hw error happens
hugetlbfs: zero partial pages during fallocate hole punch
mm: memcontrol: reference to tools/cgroup/memcg_slabinfo.py
mm: re-allow pinning of zero pfns
mm/kfence: select random number before taking raw lock
MAINTAINERS: add maillist information for LoongArch
MAINTAINERS: update MM tree references
MAINTAINERS: update Abel Vesa's email
MAINTAINERS: add MEMORY HOT(UN)PLUG section and add David as reviewer
MAINTAINERS: add Miaohe Lin as a memory-failure reviewer
mailmap: add alias for jarkko@profian.com
mm/damon/reclaim: schedule 'damon_reclaim_timer' only after 'system_wq' is initialized
kthread: make it clear that kthread_create_on_node() might be terminated by any fatal signal
mm: lru_cache_disable: use synchronize_rcu_expedited
mm/page_isolation.c: fix one kernel-doc comment
Commit 793917d997 ("mm/readahead: Add large folio readahead")
introduced support for using large folios for filebacked pages if the
filesystem supports it.
page_cache_ra_order() was introduced to allocate and add these large
folios to the page cache. However adding pages to the page cache should
be serialized against truncation and hole punching by taking
invalidate_lock. Not doing so can lead to data races resulting in stale
data getting added to the page cache and marked up-to-date. See commit
730633f0b7 ("mm: Protect operations adding pages to page cache with
invalidate_lock") for more details.
This issue was found by inspection but a testcase revealed it was
possible to observe in practice on XFS. Fix this by taking
invalidate_lock in page_cache_ra_order(), to mirror what is done for the
non-thp case in page_cache_ra_unbounded().
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Fixes: 793917d997 ("mm/readahead: Add large folio readahead")
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
