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Author SHA1 Message Date
Alex Shi (tencent)
452e862f43 mm/ksm: replace set_page_stable_node by folio_set_stable_node
Only single page could be reached where we set stable node after write
protect, so use folio converted func to replace page's.  And remove the
unused func set_page_stable_node().

Link: https://lkml.kernel.org/r/20240411061713.1847574-11-alexs@kernel.org
Signed-off-by: Alex Shi (tencent) <alexs@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:34 -07:00
David Hildenbrand
85b67b0104 mm/ksm: rename get_ksm_page_flags to ksm_get_folio_flags
As we are removing get_ksm_page_flags(), make the flags match the new
function name.

Link: https://lkml.kernel.org/r/20240411061713.1847574-10-alexs@kernel.org
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Alex Shi <alexs@kernel.org>
Reviewed-by: Alex Shi <alexs@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:34 -07:00
Alex Shi (tencent)
79899cce33 mm/ksm: convert chain series funcs and replace get_ksm_page
In ksm stable tree all page are single, let's convert them to use and
folios as well as stable_tree_insert/stable_tree_search funcs.  And
replace get_ksm_page() by ksm_get_folio() since there is no more needs.

It could save a few compound_head calls.

Link: https://lkml.kernel.org/r/20240411061713.1847574-9-alexs@kernel.org
Signed-off-by: Alex Shi (tencent) <alexs@kernel.org>
Cc: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:34 -07:00
Alex Shi (tencent)
40d707f33d mm/ksm: use folio in write_protect_page
Compound page is checked and skipped before write_protect_page() called,
use folio to save a few compound_head checks.

Link: https://lkml.kernel.org/r/20240411061713.1847574-8-alexs@kernel.org
Signed-off-by: Alex Shi (tencent) <alexs@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:34 -07:00
Alex Shi (tencent)
72556a4c06 mm/ksm: use ksm_get_folio in scan_get_next_rmap_item
Save a compound_head call.

Link: https://lkml.kernel.org/r/20240411061713.1847574-7-alexs@kernel.org
Signed-off-by: Alex Shi (tencent) <alexs@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:33 -07:00
Alex Shi (tencent)
6f528de298 mm/ksm: use folio in stable_node_dup
Use ksm_get_folio() and save 2 compound_head calls.

Link: https://lkml.kernel.org/r/20240411061713.1847574-6-alexs@kernel.org
Signed-off-by: Alex Shi (tencent) <alexs@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:33 -07:00
Alex Shi (tencent)
9d5cc14093 mm/ksm: use folio in remove_stable_node
Pages in stable tree are all single normal page, so uses ksm_get_folio()
and folio_set_stable_node(), also saves 3 calls to compound_head().

Link: https://lkml.kernel.org/r/20240411061713.1847574-5-alexs@kernel.org
Signed-off-by: Alex Shi (tencent) <alexs@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:33 -07:00
Alex Shi (tencent)
b8b0ff244d mm/ksm: add folio_set_stable_node
Turn set_page_stable_node() into a wrapper folio_set_stable_node, and then
use it to replace the former.  we will merge them together after all place
converted to folio.

Link: https://lkml.kernel.org/r/20240411061713.1847574-4-alexs@kernel.org
Signed-off-by: Alex Shi (tencent) <alexs@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:33 -07:00
Alex Shi (tencent)
f39b6e2dc1 mm/ksm: use folio in remove_rmap_item_from_tree
To save 2 compound_head calls.

Link: https://lkml.kernel.org/r/20240411061713.1847574-3-alexs@kernel.org
Signed-off-by: Alex Shi (tencent) <alexs@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:32 -07:00
Alex Shi (tencent)
b91f94729d mm/ksm: add ksm_get_folio
Patch series "transfer page to folio in KSM".

This is the first part of page to folio transfer on KSM.  Since only
single page could be stored in KSM, we could safely transfer stable tree
pages to folios.  

This patchset could reduce ksm.o 57kbytes from 2541776 bytes on latest
akpm/mm-stable branch with CONFIG_DEBUG_VM enabled.  It pass the KSM
testing in LTP and kernel selftest.

Thanks for Matthew Wilcox and David Hildenbrand's suggestions and
comments!


This patch (of 10):

The ksm only contains single pages, so we could add a new func
ksm_get_folio for get_ksm_page to use folio instead of pages to save a
couple of compound_head calls.

After all caller replaced, get_ksm_page will be removed.

Link: https://lkml.kernel.org/r/20240411061713.1847574-1-alexs@kernel.org
Link: https://lkml.kernel.org/r/20240411061713.1847574-2-alexs@kernel.org
Signed-off-by: Alex Shi (tencent) <alexs@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:32 -07:00
David Hildenbrand
7441d34922 mm/debug: print only page mapcount (excluding folio entire mapcount) in __dump_folio()
Let's simplify and only print the page mapcount: we already print the
large folio mapcount and the entire folio mapcount for large folios
separately; that should be sufficient to figure out what's happening.

While at it, print the page mapcount also if it had an underflow,
filtering out only typed pages.

Link: https://lkml.kernel.org/r/20240409192301.907377-18-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:31 -07:00
David Hildenbrand
f2f8a7a006 mm/migrate_device: use folio_mapcount() in migrate_vma_check_page()
We want to limit the use of page_mapcount() to the places where it is
absolutely necessary.  Let's convert migrate_vma_check_page() to work on a
folio internally so we can remove the page_mapcount() usage.

Note that we reject any large folios.

There is a lot more folio conversion to be had, but that has to wait for
another day.  No functional change intended.

Link: https://lkml.kernel.org/r/20240409192301.907377-15-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:31 -07:00
David Hildenbrand
f0376c7109 mm/filemap: use folio_mapcount() in filemap_unaccount_folio()
We want to limit the use of page_mapcount() to the places where it is
absolutely necessary.

Let's use folio_mapcount() instead of filemap_unaccount_folio().

No functional change intended, because we're only dealing with small
folios.

Link: https://lkml.kernel.org/r/20240409192301.907377-14-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:30 -07:00
David Hildenbrand
31ce0d7ef8 mm/migrate: use folio_likely_mapped_shared() in add_page_for_migration()
We want to limit the use of page_mapcount() to the places where it is
absolutely necessary.  In add_page_for_migration(), we actually want to
check if the folio is mapped shared, to reject such folios.  So let's use
folio_likely_mapped_shared() instead.

For small folios, fully mapped THP, and hugetlb folios, there is no change.
For partially mapped, shared THP, we should now do a better job at
rejecting such folios.

Link: https://lkml.kernel.org/r/20240409192301.907377-12-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:30 -07:00
David Hildenbrand
7115936ac1 mm/page_alloc: use folio_mapped() in __alloc_contig_migrate_range()
We want to limit the use of page_mapcount() to the places where it is
absolutely necessary.

For tracing purposes, we use page_mapcount() in
__alloc_contig_migrate_range().  Adding that mapcount to total_mapped
sounds strange: total_migrated and total_reclaimed would count each page
only once, not multiple times.

But then, isolate_migratepages_range() adds each folio only once to the
list.  So for large folios, we would query the mapcount of the first page
of the folio, which doesn't make too much sense for large folios.

Let's simply use folio_mapped() * folio_nr_pages(), which makes more sense
as nr_migratepages is also incremented by the number of pages in the folio
in case of successful migration.

Link: https://lkml.kernel.org/r/20240409192301.907377-11-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:30 -07:00
David Hildenbrand
33d844bb84 mm/memory-failure: use folio_mapcount() in hwpoison_user_mappings()
We want to limit the use of page_mapcount() to the places where it is
absolutely necessary.  We can only unmap full folios; page_mapped(), which
we check here, is translated to folio_mapped() -- based on
folio_mapcount().  So let's print the folio mapcount instead.

Link: https://lkml.kernel.org/r/20240409192301.907377-10-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:29 -07:00
David Hildenbrand
0a7bda4801 mm/huge_memory: use folio_mapcount() in zap_huge_pmd() sanity check
We want to limit the use of page_mapcount() to the places where it is
absolutely necessary.  Let's similarly check for folio_mapcount()
underflows instead of page_mapcount() underflows like we do in
zap_present_folio_ptes() now.

Instead of the VM_BUG_ON(), we should actually be doing something like
print_bad_pte().  For now, let's keep it simple and use WARN_ON_ONCE(),
performing that check independently of DEBUG_VM.

Link: https://lkml.kernel.org/r/20240409192301.907377-9-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:29 -07:00
David Hildenbrand
3aeea4fc83 mm/memory: use folio_mapcount() in zap_present_folio_ptes()
We want to limit the use of page_mapcount() to the places where it is
absolutely necessary.  In zap_present_folio_ptes(), let's simply check the
folio mapcount().  If there is some issue, it will underflow at some point
either way when unmapping.

As indicated already in commit 10ebac4f95 ("mm/memory: optimize
unmap/zap with PTE-mapped THP"), we already documented "If we ever have a
cheap folio_mapcount(), we might just want to check for underflows
there.".

There is no change for small folios.  For large folios, we'll now catch
more underflows when batch-unmapping, because instead of only testing the
mapcount of the first subpage, we'll test if the folio mapcount
underflows.

Link: https://lkml.kernel.org/r/20240409192301.907377-8-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:29 -07:00
David Hildenbrand
05c5323b2a mm: track mapcount of large folios in single value
Let's track the mapcount of large folios in a single value.  The mapcount
of a large folio currently corresponds to the sum of the entire mapcount
and all page mapcounts.

This sum is what we actually want to know in folio_mapcount() and it is
also sufficient for implementing folio_mapped().

With PTE-mapped THP becoming more important and more widely used, we want
to avoid looping over all pages of a folio just to obtain the mapcount of
large folios.  The comment "In the common case, avoid the loop when no
pages mapped by PTE" in folio_total_mapcount() does no longer hold for
mTHP that are always mapped by PTE.

Further, we are planning on using folio_mapcount() more frequently, and
might even want to remove page mapcounts for large folios in some kernel
configs.  Therefore, allow for reading the mapcount of large folios
efficiently and atomically without looping over any pages.

Maintain the mapcount also for hugetlb pages for simplicity.  Use the new
mapcount to implement folio_mapcount() and folio_mapped().  Make
page_mapped() simply call folio_mapped().  We can now get rid of
folio_large_is_mapped().

_nr_pages_mapped is now only used in rmap code and for debugging purposes.
Keep folio_nr_pages_mapped() around, but document that its use should be
limited to rmap internals and debugging purposes.

This change implies one additional atomic add/sub whenever
mapping/unmapping (parts of) a large folio.

As we now batch RMAP operations for PTE-mapped THP during fork(), during
unmap/zap, and when PTE-remapping a PMD-mapped THP, and we adjust the
large mapcount for a PTE batch only once, the added overhead in the common
case is small.  Only when unmapping individual pages of a large folio
(e.g., during COW), the overhead might be bigger in comparison, but it's
essentially one additional atomic operation.

Note that before the new mapcount would overflow, already our refcount
would overflow: each mapping requires a folio reference.  Extend the
focumentation of folio_mapcount().

Link: https://lkml.kernel.org/r/20240409192301.907377-5-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:28 -07:00
David Hildenbrand
46d62de7ad mm/rmap: add fast-path for small folios when adding/removing/duplicating
Let's add a fast-path for small folios to all relevant rmap functions. 
Note that only RMAP_LEVEL_PTE applies.

This is a preparation for tracking the mapcount of large folios in a
single value.

Link: https://lkml.kernel.org/r/20240409192301.907377-4-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:28 -07:00
David Hildenbrand
c5541ba378 mm: follow_pte() improvements
follow_pte() is now our main function to lookup PTEs in VM_PFNMAP/VM_IO
VMAs.  Let's perform some more sanity checks to make this exported
function harder to abuse.

Further, extend the doc a bit, it still focuses on the KVM use case with
MMU notifiers.  Drop the KVM+follow_pfn() comment, follow_pfn() is no
more, and we have other users nowadays.

Also extend the doc regarding refcounted pages and the interaction with
MMU notifiers.

KVM is one example that uses MMU notifiers and can deal with refcounted
pages properly.  VFIO is one example that doesn't use MMU notifiers, and
to prevent use-after-free, rejects refcounted pages: pfn_valid(pfn) &&
!PageReserved(pfn_to_page(pfn)).  Protection changes are less of a concern
for users like VFIO: the behavior is similar to longterm-pinning a page,
and getting the PTE protection changed afterwards.

The primary concern with refcounted pages is use-after-free, which callers
should be aware of.

Link: https://lkml.kernel.org/r/20240410155527.474777-4-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Fei Li <fei1.li@intel.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Yonghua Huang <yonghua.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:27 -07:00
David Hildenbrand
29ae7d96d1 mm: pass VMA instead of MM to follow_pte()
... and centralize the VM_IO/VM_PFNMAP sanity check in there. We'll
now also perform these sanity checks for direct follow_pte()
invocations.

For generic_access_phys(), we might now check multiple times: nothing to
worry about, really.

Link: https://lkml.kernel.org/r/20240410155527.474777-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Sean Christopherson <seanjc@google.com>	[KVM]
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Fei Li <fei1.li@intel.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Yonghua Huang <yonghua.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:27 -07:00
Huang Ying
d4a34d7fb4 mm,swap: add document about RCU read lock and swapoff interaction
During reviewing a patch to fix the race condition between
free_swap_and_cache() and swapoff() [1], it was found that the document
about how to prevent racing with swapoff isn't clear enough.  Especially
RCU read lock can prevent swapoff from freeing data structures.  So, the
document is added as comments.

[1] https://lore.kernel.org/linux-mm/c8fe62d0-78b8-527a-5bef-ee663ccdc37a@huawei.com/

Link: https://lkml.kernel.org/r/20240407065450.498821-1-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:26 -07:00
Hao Ge
2bd9e6ee99 mm/mmap: make accountable_mapping return bool
accountable_mapping() can return bool, so change it.

Link: https://lkml.kernel.org/r/20240407063843.804274-1-gehao@kylinos.cn
Signed-off-by: Hao Ge <gehao@kylinos.cn>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:26 -07:00
Hao Ge
38bc9c28c3 mm/mmap: make vma_wants_writenotify return bool
vma_wants_writenotify() should return bool, so change it.

Link: https://lkml.kernel.org/r/20240407062653.803142-1-gehao@kylinos.cn
Signed-off-by: Hao Ge <gehao@kylinos.cn>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:26 -07:00
Ho-Ren (Jack) Chuang
cf93be18fa memory tier: create CPUless memory tiers after obtaining HMAT info
The current implementation treats emulated memory devices, such as CXL1.1
type3 memory, as normal DRAM when they are emulated as normal memory
(E820_TYPE_RAM).  However, these emulated devices have different
characteristics than traditional DRAM, making it important to distinguish
them.  Thus, we modify the tiered memory initialization process to
introduce a delay specifically for CPUless NUMA nodes.  This delay ensures
that the memory tier initialization for these nodes is deferred until HMAT
information is obtained during the boot process.  Finally, demotion tables
are recalculated at the end.

* late_initcall(memory_tier_late_init);
  Some device drivers may have initialized memory tiers between
  `memory_tier_init()` and `memory_tier_late_init()`, potentially bringing
  online memory nodes and configuring memory tiers.  They should be
  excluded in the late init.

* Handle cases where there is no HMAT when creating memory tiers
  There is a scenario where a CPUless node does not provide HMAT
  information.  If no HMAT is specified, it falls back to using the
  default DRAM tier.

* Introduce another new lock `default_dram_perf_lock` for adist
  calculation In the current implementation, iterating through CPUlist
  nodes requires holding the `memory_tier_lock`.  However,
  `mt_calc_adistance()` will end up trying to acquire the same lock,
  leading to a potential deadlock.  Therefore, we propose introducing a
  standalone `default_dram_perf_lock` to protect `default_dram_perf_*`. 
  This approach not only avoids deadlock but also prevents holding a large
  lock simultaneously.

* Upgrade `set_node_memory_tier` to support additional cases, including
  default DRAM, late CPUless, and hot-plugged initializations.  To cover
  hot-plugged memory nodes, `mt_calc_adistance()` and
  `mt_find_alloc_memory_type()` are moved into `set_node_memory_tier()` to
  handle cases where memtype is not initialized and where HMAT information
  is available.

* Introduce `default_memory_types` for those memory types that are not
  initialized by device drivers.  Because late initialized memory and
  default DRAM memory need to be managed, a default memory type is created
  for storing all memory types that are not initialized by device drivers
  and as a fallback.

Link: https://lkml.kernel.org/r/20240405000707.2670063-3-horenchuang@bytedance.com
Signed-off-by: Ho-Ren (Jack) Chuang <horenchuang@bytedance.com>
Signed-off-by: Hao Xiang <hao.xiang@bytedance.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Gregory Price <gourry.memverge@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Ravi Jonnalagadda <ravis.opensrc@micron.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawie.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:26 -07:00
Ho-Ren (Jack) Chuang
a72a30af55 memory tier: dax/kmem: introduce an abstract layer for finding, allocating, and putting memory types
Patch series "Improved Memory Tier Creation for CPUless NUMA Nodes", v11.

When a memory device, such as CXL1.1 type3 memory, is emulated as normal
memory (E820_TYPE_RAM), the memory device is indistinguishable from normal
DRAM in terms of memory tiering with the current implementation.  The
current memory tiering assigns all detected normal memory nodes to the
same DRAM tier.  This results in normal memory devices with different
attributions being unable to be assigned to the correct memory tier,
leading to the inability to migrate pages between different types of
memory. 
https://lore.kernel.org/linux-mm/PH0PR08MB7955E9F08CCB64F23963B5C3A860A@PH0PR08MB7955.namprd08.prod.outlook.com/T/

This patchset automatically resolves the issues.  It delays the
initialization of memory tiers for CPUless NUMA nodes until they obtain
HMAT information and after all devices are initialized at boot time,
eliminating the need for user intervention.  If no HMAT is specified, it
falls back to using `default_dram_type`.

Example usecase:
We have CXL memory on the host, and we create VMs with a new system memory
device backed by host CXL memory.  We inject CXL memory performance
attributes through QEMU, and the guest now sees memory nodes with
performance attributes in HMAT.  With this change, we enable the guest
kernel to construct the correct memory tiering for the memory nodes.


This patch (of 2):

Since different memory devices require finding, allocating, and putting
memory types, these common steps are abstracted in this patch, enhancing
the scalability and conciseness of the code.

Link: https://lkml.kernel.org/r/20240405000707.2670063-1-horenchuang@bytedance.com
Link: https://lkml.kernel.org/r/20240405000707.2670063-2-horenchuang@bytedance.com
Signed-off-by: Ho-Ren (Jack) Chuang <horenchuang@bytedance.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawie.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Gregory Price <gourry.memverge@gmail.com>
Cc: Hao Xiang <hao.xiang@bytedance.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Ravi Jonnalagadda <ravis.opensrc@micron.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:25 -07:00
Christoph Hellwig
77ddd726f9 mm,page_owner: don't remove __GFP_NOLOCKDEP in add_stack_record_to_list
Otherwise we'll generate false lockdep positives.

Link: https://lkml.kernel.org/r/20240429082828.1615986-1-hch@lst.de
Fixes: 217b2119b9 ("mm,page_owner: implement the tracking of the stacks count")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Oscar Salvador <osalvador@suse.de>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:28:07 -07:00
Hailong.Liu
ac0476e8ca mm/vmalloc: fix return value of vb_alloc if size is 0
vm_map_ram() uses IS_ERR() to validate the return value of vb_alloc().  If
vm_map_ram(page, 0, 0) is executed, vb_alloc(0, GFP_KERNEL) would return
NULL.  In such a case, IS_ERR() cannot handle the return value and lead to
kernel panic by vmap_pages_range_noflush() at last.  To resolve this
issue, return ERR_PTR(-EINVAL) if the size is 0.

Link: https://lkml.kernel.org/r/20240426024149.21176-1-hailong.liu@oppo.com
Reviewed-by: Barry Song <baohua@kernel.org>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Hailong.Liu <hailong.liu@oppo.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:28:06 -07:00
Kefeng Wang
30153e4466 mm: use memalloc_nofs_save() in page_cache_ra_order()
See commit f2c817bed5 ("mm: use memalloc_nofs_save in readahead path"),
ensure that page_cache_ra_order() do not attempt to reclaim file-backed
pages too, or it leads to a deadlock, found issue when test ext4 large
folio.

 INFO: task DataXceiver for:7494 blocked for more than 120 seconds.
 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
 task:DataXceiver for state:D stack:0     pid:7494  ppid:1      flags:0x00000200
 Call trace:
  __switch_to+0x14c/0x240
  __schedule+0x82c/0xdd0
  schedule+0x58/0xf0
  io_schedule+0x24/0xa0
  __folio_lock+0x130/0x300
  migrate_pages_batch+0x378/0x918
  migrate_pages+0x350/0x700
  compact_zone+0x63c/0xb38
  compact_zone_order+0xc0/0x118
  try_to_compact_pages+0xb0/0x280
  __alloc_pages_direct_compact+0x98/0x248
  __alloc_pages+0x510/0x1110
  alloc_pages+0x9c/0x130
  folio_alloc+0x20/0x78
  filemap_alloc_folio+0x8c/0x1b0
  page_cache_ra_order+0x174/0x308
  ondemand_readahead+0x1c8/0x2b8
  page_cache_async_ra+0x68/0xb8
  filemap_readahead.isra.0+0x64/0xa8
  filemap_get_pages+0x3fc/0x5b0
  filemap_splice_read+0xf4/0x280
  ext4_file_splice_read+0x2c/0x48 [ext4]
  vfs_splice_read.part.0+0xa8/0x118
  splice_direct_to_actor+0xbc/0x288
  do_splice_direct+0x9c/0x108
  do_sendfile+0x328/0x468
  __arm64_sys_sendfile64+0x8c/0x148
  invoke_syscall+0x4c/0x118
  el0_svc_common.constprop.0+0xc8/0xf0
  do_el0_svc+0x24/0x38
  el0_svc+0x4c/0x1f8
  el0t_64_sync_handler+0xc0/0xc8
  el0t_64_sync+0x188/0x190

Link: https://lkml.kernel.org/r/20240426112938.124740-1-wangkefeng.wang@huawei.com
Fixes: 793917d997 ("mm/readahead: Add large folio readahead")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Zhang Yi <yi.zhang@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:28:06 -07:00
Maninder Singh
e7af4014b4 mm: page_owner: fix wrong information in dump_page_owner
With commit ea4b5b33bf ("mm,page_owner: update metadata for tail
pages"), new API __update_page_owner_handle was introduced and arguemnt
was passed in wrong order from __set_page_owner and thus page_owner is
giving wrong data.

[   15.982420] page last allocated via order 0, migratetype Unmovable, gfp_mask 0xcc0(GFP_KERNEL), pid 80, tgid -1210279584 (insmod), ts 80, free_ts 0

Fixing the same.
Correct output:
[   14.556482] page last allocated via order 0, migratetype Unmovable, gfp_mask 0xcc0(GFP_KERNEL), pid 80, tgid 80 (insmod), ts 14552004992, free_ts 0

Link: https://lkml.kernel.org/r/20240424111838.3782931-1-hariom1.p@samsung.com
Fixes: ea4b5b33bf ("mm,page_owner: update metadata for tail pages")
Signed-off-by: Maninder Singh <maninder1.s@samsung.com>
Signed-off-by: Hariom Panthi <hariom1.p@samsung.com>
Acked-by: Oscar Salvador <osalvador@suse.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Rohit Thapliyal <r.thapliyal@samsung.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:28:05 -07:00
Al Viro
51d908b3db swapon(2): open swap with O_EXCL
... eliminating the need to reopen block devices so they could be
exclusively held.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-05-02 17:23:30 -04:00
Al Viro
798cb7f9ae swapon(2)/swapoff(2): don't bother with block size
once upon a time that used to matter; these days we do swap IO for
swap devices at the level that doesn't give a damn about block size,
buffer_head or anything of that sort - just attach the page to
bio, set the location and size (the latter to PAGE_SIZE) and feed
into queue.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-05-02 17:23:30 -04:00
Hyunmin Lee
7338999ca3 mm/slub: remove the check for NULL kmalloc_caches
If the same size kmalloc cache already exists, it should not be created
again. So there is the check for NULL kmalloc_caches before calling the
kmalloc creation function. However, new_kmalloc_cache() itself checks NULL
kmalloc_cahces before cache creation. Therefore, the NULL check is not
necessary in this function.

Signed-off-by: Hyunmin Lee <hyunminlr@gmail.com>
Co-developed-by: Jeungwoo Yoo <casionwoo@gmail.com>
Signed-off-by: Jeungwoo Yoo <casionwoo@gmail.com>
Co-developed-by: Sangyun Kim <sangyun.kim@snu.ac.kr>
Signed-off-by: Sangyun Kim <sangyun.kim@snu.ac.kr>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-05-02 16:09:40 +02:00
Hyunmin Lee
306c4ac989 mm/slub: create kmalloc 96 and 192 caches regardless cache size order
For SLAB the kmalloc caches needed to be created in ascending sizes in
order. However, the constraint is not necessary anymore because SLAB has
been removed and SLUB doesn't need to comply with the constraint. Thus,
kmalloc 96 and 192 caches can be created after the other size kmalloc
caches are created instead of checking every time to find their order to
be created. Also, this change could prevent engineers from being confused
by the removed constraint.

Signed-off-by: Hyunmin Lee <hyunminlr@gmail.com>
Co-developed-by: Jeungwoo Yoo <casionwoo@gmail.com>
Signed-off-by: Jeungwoo Yoo <casionwoo@gmail.com>
Co-developed-by: Sangyun Kim <sangyun.kim@snu.ac.kr>
Signed-off-by: Sangyun Kim <sangyun.kim@snu.ac.kr>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-05-02 16:09:40 +02:00
linke li
844776cb65 mm/slub: mark racy access on slab->freelist
In deactivate_slab(), slab->freelist can be changed concurrently. Mark
data race on slab->freelist as benign using READ_ONCE.

This patch is aimed at reducing the number of benign races reported by
KCSAN in order to focus future debugging effort on harmful races.

Signed-off-by: linke li <lilinke99@qq.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-05-02 14:19:21 +02:00
David Howells
5a550a0c60 mm: Export writeback_iter()
Export writeback_iter() so that it can be used by netfslib as a module.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: Matthew Wilcox (Oracle) <willy@infradead.org>
cc: Christoph Hellwig <hch@lst.de>
cc: linux-mm@kvack.org
2024-05-01 18:07:35 +01:00
David Howells
74e797d79c mm: Provide a means of invalidation without using launder_folio
Implement a replacement for launder_folio.  The key feature of
invalidate_inode_pages2() is that it locks each folio individually, unmaps
it to prevent mmap'd accesses interfering and calls the ->launder_folio()
address_space op to flush it.  This has problems: firstly, each folio is
written individually as one or more small writes; secondly, adjacent folios
cannot be added so easily into the laundry; thirdly, it's yet another op to
implement.

Instead, use the invalidate lock to cause anyone wanting to add a folio to
the inode to wait, then unmap all the folios if we have mmaps, then,
conditionally, use ->writepages() to flush any dirty data back and then
discard all pages.

The invalidate lock prevents ->read_iter(), ->write_iter() and faulting
through mmap all from adding pages for the duration.

This is then used from netfslib to handle the flusing in unbuffered and
direct writes.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Matthew Wilcox <willy@infradead.org>
cc: Miklos Szeredi <miklos@szeredi.hu>
cc: Trond Myklebust <trond.myklebust@hammerspace.com>
cc: Christoph Hellwig <hch@lst.de>
cc: Andrew Morton <akpm@linux-foundation.org>
cc: Alexander Viro <viro@zeniv.linux.org.uk>
cc: Christian Brauner <brauner@kernel.org>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-mm@kvack.org
cc: linux-fsdevel@vger.kernel.org
cc: netfs@lists.linux.dev
cc: v9fs@lists.linux.dev
cc: linux-afs@lists.infradead.org
cc: ceph-devel@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: linux-nfs@vger.kernel.org
cc: devel@lists.orangefs.org
2024-05-01 18:07:06 +01:00
Nicolas Bouchinet
8f828aa488 mm/slub: avoid zeroing outside-object freepointer for single free
Commit 284f17ac13 ("mm/slub: handle bulk and single object freeing
separately") splits single and bulk object freeing in two functions
slab_free() and slab_free_bulk() which leads slab_free() to call
slab_free_hook() directly instead of slab_free_freelist_hook().

If `init_on_free` is set, slab_free_hook() zeroes the object.
Afterward, if `slub_debug=F` and `CONFIG_SLAB_FREELIST_HARDENED` are
set, the do_slab_free() slowpath executes freelist consistency
checks and try to decode a zeroed freepointer which leads to a
"Freepointer corrupt" detection in check_object().

During bulk free, slab_free_freelist_hook() isn't affected as it always
sets it objects freepointer using set_freepointer() to maintain its
reconstructed freelist after `init_on_free`.

For single free, object's freepointer thus needs to be avoided when
stored outside the object if `init_on_free` is set. The freepointer left
as is, check_object() may later detect an invalid pointer value due to
objects overflow.

To reproduce, set `slub_debug=FU init_on_free=1 log_level=7` on the
command line of a kernel build with `CONFIG_SLAB_FREELIST_HARDENED=y`.

dmesg sample log:
[   10.708715] =============================================================================
[   10.710323] BUG kmalloc-rnd-05-32 (Tainted: G    B           T ): Freepointer corrupt
[   10.712695] -----------------------------------------------------------------------------
[   10.712695]
[   10.712695] Slab 0xffffd8bdc400d580 objects=32 used=4 fp=0xffff9d9a80356f80 flags=0x200000000000a00(workingset|slab|node=0|zone=2)
[   10.716698] Object 0xffff9d9a80356600 @offset=1536 fp=0x7ee4f480ce0ecd7c
[   10.716698]
[   10.716698] Bytes b4 ffff9d9a803565f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
[   10.720703] Object   ffff9d9a80356600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
[   10.720703] Object   ffff9d9a80356610: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
[   10.724696] Padding  ffff9d9a8035666c: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
[   10.724696] Padding  ffff9d9a8035667c: 00 00 00 00                                      ....
[   10.724696] FIX kmalloc-rnd-05-32: Object at 0xffff9d9a80356600 not freed

Fixes: 284f17ac13 ("mm/slub: handle bulk and single object freeing separately")
Cc: <stable@vger.kernel.org>
Co-developed-by: Chengming Zhou <chengming.zhou@linux.dev>
Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev>
Signed-off-by: Nicolas Bouchinet <nicolas.bouchinet@ssi.gouv.fr>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-05-01 17:28:56 +02:00
David Howells
2e9d7e4b98 mm: Remove the PG_fscache alias for PG_private_2
Remove the PG_fscache alias for PG_private_2 and use the latter directly.
Use of this flag for marking pages undergoing writing to the cache should
be considered deprecated and the folios should be marked dirty instead and
the write done in ->writepages().

Note that PG_private_2 itself should be considered deprecated and up for
future removal by the MM folks too.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: Matthew Wilcox (Oracle) <willy@infradead.org>
cc: Ilya Dryomov <idryomov@gmail.com>
cc: Xiubo Li <xiubli@redhat.com>
cc: Steve French <sfrench@samba.org>
cc: Paulo Alcantara <pc@manguebit.com>
cc: Ronnie Sahlberg <ronniesahlberg@gmail.com>
cc: Shyam Prasad N <sprasad@microsoft.com>
cc: Tom Talpey <tom@talpey.com>
cc: Bharath SM <bharathsm@microsoft.com>
cc: Trond Myklebust <trond.myklebust@hammerspace.com>
cc: Anna Schumaker <anna@kernel.org>
cc: netfs@lists.linux.dev
cc: ceph-devel@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: linux-nfs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
2024-04-29 15:01:42 +01:00
Joerg Roedel
5dc72c8a14 Merge branch 'memory-observability' into x86/amd 2024-04-26 12:54:13 +02:00
Alexander Potapenko
3429055f04 mm: kmsan: implement kmsan_memmove()
Provide a hook that can be used by custom memcpy implementations to tell
KMSAN that the metadata needs to be copied.  Without that, false positive
reports are possible in the cases where KMSAN fails to intercept memory
initialization.

Link: https://lore.kernel.org/all/3b7dbd88-0861-4638-b2d2-911c97a4cadf@I-love.SAKURA.ne.jp/
Link: https://lkml.kernel.org/r/20240320101851.2589698-1-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Suggested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 21:07:02 -07:00
Matthew Wilcox (Oracle)
9f100e3b37 mm: convert free_zone_device_page to free_zone_device_folio
Both callers already have a folio; pass it in and save a few calls to
compound_head().

Link: https://lkml.kernel.org/r/20240405153228.2563754-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:44 -07:00
Matthew Wilcox (Oracle)
79a4828751 mm: combine __folio_put_small, __folio_put_large and __folio_put
It's now obvious that __folio_put_small() and __folio_put_large() do
almost exactly the same thing.  Inline them both into __folio_put().

Link: https://lkml.kernel.org/r/20240405153228.2563754-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:44 -07:00
Matthew Wilcox (Oracle)
2542b1ac9a mm: inline destroy_large_folio() into __folio_put_large()
destroy_large_folio() has only one caller, move its contents there.

Link: https://lkml.kernel.org/r/20240405153228.2563754-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:44 -07:00
Matthew Wilcox (Oracle)
5b8d75913a mm: combine free_the_page() and free_unref_page()
The pcp_allowed_order() check in free_the_page() was only being skipped by
__folio_put_small() which is about to be rearranged.

Link: https://lkml.kernel.org/r/20240405153228.2563754-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:43 -07:00
Matthew Wilcox (Oracle)
2f16670429 mm: free non-hugetlb large folios in a batch
Patch series "Clean up __folio_put()".

With all the changes over the last few years, __folio_put_small and
__folio_put_large have become almost identical to each other ...  except
you can't tell because they're spread over two files.  Rearrange it all so
that you can tell, and then inline them both into __folio_put().


This patch (of 5):

free_unref_folios() can now handle non-hugetlb large folios, so keep
normal large folios in the batch.  hugetlb folios still need to be handled
specially.

[peterx@redhat.com: fix panic]
  Link: https://lkml.kernel.org/r/ZikjPB0Dt5HA8-uL@x1n
Link: https://lkml.kernel.org/r/20240405153228.2563754-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20240405153228.2563754-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:43 -07:00
Matthew Wilcox (Oracle)
2ebe90dab9 mm: convert pagecache_isize_extended to use a folio
Remove four hidden calls to compound_head().  Also exit early if the
filesystem block size is >= PAGE_SIZE instead of just equal to PAGE_SIZE.

Link: https://lkml.kernel.org/r/20240405180038.2618624-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:43 -07:00
Frank van der Linden
55d134a7b4 mm/hugetlb: pass correct order_per_bit to cma_declare_contiguous_nid
The hugetlb_cma code passes 0 in the order_per_bit argument to
cma_declare_contiguous_nid (the alignment, computed using the page order,
is correctly passed in).

This causes a bit in the cma allocation bitmap to always represent a 4k
page, making the bitmaps potentially very large, and slower.

It would create bitmaps that would be pretty big.  E.g.  for a 4k page
size on x86, hugetlb_cma=64G would mean a bitmap size of (64G / 4k) / 8
== 2M.  With HUGETLB_PAGE_ORDER as order_per_bit, as intended, this
would be (64G / 2M) / 8 == 4k.  So, that's quite a difference.

Also, this restricted the hugetlb_cma area to ((PAGE_SIZE <<
MAX_PAGE_ORDER) * 8) * PAGE_SIZE (e.g.  128G on x86) , since
bitmap_alloc uses normal page allocation, and is thus restricted by
MAX_PAGE_ORDER.  Specifying anything about that would fail the CMA
initialization.

So, correctly pass in the order instead.

Link: https://lkml.kernel.org/r/20240404162515.527802-2-fvdl@google.com
Fixes: cf11e85fc0 ("mm: hugetlb: optionally allocate gigantic hugepages using cma")
Signed-off-by: Frank van der Linden <fvdl@google.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:43 -07:00
Frank van der Linden
b174f139bd mm/cma: drop incorrect alignment check in cma_init_reserved_mem
cma_init_reserved_mem uses IS_ALIGNED to check if the size represented by
one bit in the cma allocation bitmask is aligned with
CMA_MIN_ALIGNMENT_BYTES (pageblock size).

However, this is too strict, as this will fail if order_per_bit >
pageblock_order, which is a valid configuration.

We could check IS_ALIGNED both ways, but since both numbers are powers of
two, no check is needed at all.

Link: https://lkml.kernel.org/r/20240404162515.527802-1-fvdl@google.com
Fixes: de9e14eebf ("drivers: dma-contiguous: add initialization from device tree")
Signed-off-by: Frank van der Linden <fvdl@google.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:42 -07:00