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Christoph reports a page allocator splat triggered by xfstests:
generic/176 214s ... [ 1204.507931] run fstests generic/176 at 2024-05-27 12:52:30
XFS (nvme0n1): Mounting V5 Filesystem cd936307-415f-48a3-b99d-a2d52ae1f273
XFS (nvme0n1): Ending clean mount
XFS (nvme1n1): Mounting V5 Filesystem ab3ee1a4-af62-4934-9a6a-6c2fde321850
XFS (nvme1n1): Ending clean mount
XFS (nvme1n1): Unmounting Filesystem ab3ee1a4-af62-4934-9a6a-6c2fde321850
XFS (nvme1n1): Mounting V5 Filesystem 7099b02d-9c58-4d1d-be1d-2cc472d12cd9
XFS (nvme1n1): Ending clean mount
------------[ cut here ]------------
page type is 3, passed migratetype is 1 (nr=512)
WARNING: CPU: 0 PID: 509870 at mm/page_alloc.c:645 expand+0x1c5/0x1f0
Modules linked in: i2c_i801 crc32_pclmul i2c_smbus [last unloaded: scsi_debug]
CPU: 0 PID: 509870 Comm: xfs_io Not tainted 6.10.0-rc1+ #2437
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:expand+0x1c5/0x1f0
Code: 05 16 70 bf 02 01 e8 ca fc ff ff 8b 54 24 34 44 89 e1 48 c7 c7 80 a2 28 83 48 89 c6 b8 01 00 3
RSP: 0018:ffffc90003b2b968 EFLAGS: 00010082
RAX: 0000000000000000 RBX: ffffffff83fa9480 RCX: 0000000000000000
RDX: 0000000000000005 RSI: 0000000000000027 RDI: 00000000ffffffff
RBP: 00000000001f2600 R08: 00000000fffeffff R09: 0000000000000001
R10: 0000000000000000 R11: ffffffff83676200 R12: 0000000000000009
R13: 0000000000000200 R14: 0000000000000001 R15: ffffea0007c98000
FS: 00007f72ca3d5780(0000) GS:ffff8881f9c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f72ca1fff38 CR3: 00000001aa0c6002 CR4: 0000000000770ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff07f0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
<TASK>
? __warn+0x7b/0x120
? expand+0x1c5/0x1f0
? report_bug+0x191/0x1c0
? handle_bug+0x3c/0x80
? exc_invalid_op+0x17/0x70
? asm_exc_invalid_op+0x1a/0x20
? expand+0x1c5/0x1f0
? expand+0x1c5/0x1f0
__rmqueue_pcplist+0x3a9/0x730
get_page_from_freelist+0x7a0/0xf00
__alloc_pages_noprof+0x153/0x2e0
__folio_alloc_noprof+0x10/0xa0
__filemap_get_folio+0x16b/0x370
iomap_write_begin+0x496/0x680
While trying to service a movable allocation (page type 1), the page
allocator runs into a two-pageblock buddy on the movable freelist whose
second block is typed as highatomic (page type 3).
This inconsistency is caused by the highatomic reservation system
operating on single pageblocks, while MAX_ORDER can be bigger than that -
in this configuration, pageblock_order is 9 while MAX_PAGE_ORDER is 10.
The test case is observed to make several adjacent order-3 requests with
__GFP_DIRECT_RECLAIM cleared, which marks the surrounding block as
highatomic. Upon freeing, the blocks merge into an order-10 buddy. When
the highatomic pool is drained later on, this order-10 buddy gets moved
back to the movable list, but only the first pageblock is marked movable
again. A subsequent expand() of this buddy warns about the tail being of
a different type.
This is a long-standing bug that's surfaced by the recent block type
warnings added to the allocator. The consequences seem mostly benign, it
just results in odd behavior: the highatomic tail blocks are not properly
drained, instead they end up on the movable list first, then go back to
the highatomic list after an alloc-free cycle.
To fix this, make the highatomic reservation code aware that
allocations/buddies can be larger than a pageblock.
While it's an old quirk, the recently added type consistency warnings seem
to be the most prominent consequence of it. Set the Fixes: tag
accordingly to highlight this backporting dependency.
Link: https://lkml.kernel.org/r/20240530114203.GA1222079@cmpxchg.org
Fixes: e0932b6c1f94 ("mm: page_alloc: consolidate free page accounting")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Tested-by: Christoph Hellwig <hch@lst.de>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Currently, compaction_capture() does not allow lower-order allocations to
directly capture the movable free pages, even though lower-order
allocations might also be requesting movable pages, that can lead to more
compaction scanning. And, with the enablement of mTHP, such situations
will become more common.
Thus allowing lower-order (mTHP) allocations of movable page types
directly capture the movable free pages can avoid unnecessary compaction
scanning, meanwhile that won't pollute the movable pageblock. With
testing 1M mTHP compaction, it can be seen that compaction scanning is
significantly reduced.
mm-unstable patched
Ops Compaction pages isolated 116598741.00 120946702.00
Ops Compaction migrate scanned 1764870054.00 1488621550.00
Ops Compaction free scanned 7707879039.00 4986299318.00
Ops Compact scan efficiency 22.90 29.85
Ops Compaction cost 73797.69 72933.48
Link: https://lkml.kernel.org/r/8118a5d66a034736a48433beddaca60ed78577c4.1712892329.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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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>
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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>
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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>
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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>
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Commit 44042b449872 ("mm/page_alloc: allow high-order pages to be stored
on the per-cpu lists") extends the PCP allocator to store THP pages, and
it determines whether to cache THP pages in PCP by comparing with
pageblock_order. But the pageblock_order is not always equal to THP
order. It might also be MAX_PAGE_ORDER, which could prevent PCP from
caching THP pages.
Therefore, using HPAGE_PMD_ORDER instead to determine the need for caching
THP for PCP will fix this issue
Link: https://lkml.kernel.org/r/a25c9e14cd03907d5978b60546a69e6aa3fc2a7d.1712151833.git.baolin.wang@linux.alibaba.com
Fixes: 44042b449872 ("mm/page_alloc: allow high-order pages to be stored on the per-cpu lists")
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Barry Song <baohua@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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This commit comes at the tail end of a greater effort to remove the empty
elements at the end of the ctl_table arrays (sentinels) which will reduce
the overall build time size of the kernel and run time memory bloat by ~64
bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)
Remove sentinel from all files under mm/ that register a sysctl table.
Link: https://lkml.kernel.org/r/20240328-jag-sysctl_remset_misc-v1-1-47c1463b3af2@samsung.com
Signed-off-by: Joel Granados <j.granados@samsung.com>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Implements the "init_mlocked_on_free" boot option. When this boot option
is enabled, any mlock'ed pages are zeroed on free. If
the pages are munlock'ed beforehand, no initialization takes place.
This boot option is meant to combat the performance hit of
"init_on_free" as reported in commit 6471384af2a6 ("mm: security:
introduce init_on_alloc=1 and init_on_free=1 boot options"). With
"init_mlocked_on_free=1" only relevant data is freed while everything
else is left untouched by the kernel. Correspondingly, this patch
introduces no performance hit for unmapping non-mlock'ed memory. The
unmapping overhead for purely mlocked memory was measured to be
approximately 13%. Realistically, most systems mlock only a fraction of
the total memory so the real-world system overhead should be close to
zero.
Optimally, userspace programs clear any key material or other
confidential memory before exit and munlock the according memory
regions. If a program crashes, userspace key managers fail to do this
job. Accordingly, no munlock operations are performed so the data is
caught and zeroed by the kernel. Should the program not crash, all
memory will ideally be munlocked so no overhead is caused.
CONFIG_INIT_MLOCKED_ON_FREE_DEFAULT_ON can be set to enable
"init_mlocked_on_free" by default.
Link: https://lkml.kernel.org/r/20240329145605.149917-1-yjnworkstation@gmail.com
Signed-off-by: York Jasper Niebuhr <yjnworkstation@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: York Jasper Niebuhr <yjnworkstation@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Earlier, in commit 1dd214b8f21c ("mm: page_alloc: avoid merging
non-fallbackable pageblocks with others"), migrate type MIGRATE_CMA and
MIGRATE_ISOLATE are removed from fallbacks list since they are never used.
Later on, in commit ("aa02d3c174ab mm/page_alloc: reduce fallbacks to
(MIGRATE_PCPTYPES - 1)"), the array column size is reduced to
'MIGRATE_PCPTYPES - 1'. In fact, the array row size need be reduced to
MIGRATE_PCPTYPES too since it's only covering rows of the number
MIGRATE_PCPTYPES. Even though the current code has handled cases
when the migratetype is CMA, HIGHATOMIC and MEMORY_ISOLATION, making
the row size right is still good to avoid future error and confusion.
Link: https://lkml.kernel.org/r/20240326061134.1055295-8-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: "Mike Rapoport (IBM)" <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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empty zone
On one node, for lower zone's ->lowmem_reserve[], it will show how much
memory is reserved in this lower zone to avoid excessive page allocation
from the relevant higher zone's fallback allocation.
However, currently lower zone's lowmem_reserve[] element will be filled
even though the relevant higher zone is empty. That doesnt' make sense
and can cause confusion.
E.g on node 0 of one system as below, it has zone
DMA/DMA32/NORMAL/MOVABLE/DEVICE, among them zone MOVABLE/DEVICE are the
highest and both are empty. In zone DMA/DMA32's protection array, we can
see that it has value for zone MOVABLE and DEVICE.
Node 0, zone DMA
......
pages free 2816
boost 0
min 7
low 10
high 13
spanned 4095
present 3998
managed 3840
cma 0
protection: (0, 1582, 23716, 23716, 23716)
......
Node 0, zone DMA32
pages free 403269
boost 0
min 753
low 1158
high 1563
spanned 1044480
present 487039
managed 405070
cma 0
protection: (0, 0, 22134, 22134, 22134)
......
Node 0, zone Normal
pages free 5423879
boost 0
min 10539
low 16205
high 21871
spanned 5767168
present 5767168
managed 5666438
cma 0
protection: (0, 0, 0, 0, 0)
......
Node 0, zone Movable
pages free 0
boost 0
min 32
low 32
high 32
spanned 0
present 0
managed 0
cma 0
protection: (0, 0, 0, 0, 0)
Node 0, zone Device
pages free 0
boost 0
min 0
low 0
high 0
spanned 0
present 0
managed 0
cma 0
protection: (0, 0, 0, 0, 0)
Here, clear out the element value in lower zone's ->lowmem_reserve[] if the
relevant higher zone is empty.
And also replace space with tab in _deferred_grow_zone()
Link: https://lkml.kernel.org/r/20240326061134.1055295-7-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: "Mike Rapoport (IBM)" <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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When CONFIG_NUMA=n, MAX_NUMNODES is always 1 because Kconfig item
NODES_SHIFT depends on NUMA. So in !NUMA version of build_zonelists(), no
need to bother with the two for loop because code execution won't enter
them ever.
Here, remove those unneeded codes in !NUMA version of build_zonelists().
[bhe@redhat.com: remove unused locals]
Link: https://lkml.kernel.org/r/ZgQL1WOf9K88nLpQ@MiWiFi-R3L-srv
Link: https://lkml.kernel.org/r/20240326061134.1055295-5-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: "Mike Rapoport (IBM)" <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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This function does not modify its argument; let the callers know that so
they can make better optimisation decisions.
Link: https://lkml.kernel.org/r/20240326171045.410737-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "make the hugetlb migration strategy consistent", v2.
As discussed in previous thread [1], there is an inconsistency when
handling hugetlb migration. When handling the migration of freed hugetlb,
it prevents fallback to other NUMA nodes in
alloc_and_dissolve_hugetlb_folio(). However, when dealing with in-use
hugetlb, it allows fallback to other NUMA nodes in
alloc_hugetlb_folio_nodemask(), which can break the per-node hugetlb pool
and might result in unexpected failures when node bound workloads doesn't
get what is asssumed available.
This patchset tries to make the hugetlb migration strategy more clear
and consistent. Please find details in each patch.
[1]
https://lore.kernel.org/all/6f26ce22d2fcd523418a085f2c588fe0776d46e7.1706794035.git.baolin.wang@linux.alibaba.com/
This patch (of 2):
To support different hugetlb allocation strategies during hugetlb
migration based on various migration reasons, record the migration reason
in the migration_target_control structure as a preparation.
Link: https://lkml.kernel.org/r/cover.1709719720.git.baolin.wang@linux.alibaba.com
Link: https://lkml.kernel.org/r/7b95d4981e07211f57139fc5b1f7ce91b920cee4.1709719720.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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expand() currently updates vmstat for every subpage. This is unnecessary,
since they're all of the same zone and migratetype.
Count added pages locally, then do a single vmstat update.
Link: https://lkml.kernel.org/r/20240327190111.GC7597@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The function is now supposed to be called only on a single pageblock and
checks start_pfn and end_pfn accordingly. Rename it to make this more
obvious and drop the end_pfn parameter which can be determined trivially
and none of the callers use it for anything else.
Also make the (now internal) end_pfn exclusive, which is more common.
Link: https://lkml.kernel.org/r/81b1d642-2ec0-49f5-89fc-19a3828419ff@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Free page accounting currently happens a bit too high up the call stack,
where it has to deal with guard pages, compaction capturing, block
stealing and even page isolation. This is subtle and fragile, and makes
it difficult to hack on the code.
Now that type violations on the freelists have been fixed, push the
accounting down to where pages enter and leave the freelist.
[hannes@cmpxchg.org: undo unrelated drive-by line wrap]
Link: https://lkml.kernel.org/r/20240327185736.GA7597@cmpxchg.org
[hannes@cmpxchg.org: remove unused page parameter from account_freepages()]
Link: https://lkml.kernel.org/r/20240327185831.GB7597@cmpxchg.org
[baolin.wang@linux.alibaba.com: fix free page accounting]
Link: https://lkml.kernel.org/r/a2a48baca69f103aa431fd201f8a06e3b95e203d.1712648441.git.baolin.wang@linux.alibaba.com
[andriy.shevchenko@linux.intel.com: avoid defining unused function]
Link: https://lkml.kernel.org/r/20240423161506.2637177-1-andriy.shevchenko@linux.intel.com
Link: https://lkml.kernel.org/r/20240320180429.678181-11-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Page isolation currently sets MIGRATE_ISOLATE on a block, then drops
zone->lock and scans the block for straddling buddies to split up.
Because this happens non-atomically wrt the page allocator, it's possible
for allocations to get a buddy whose first block is a regular pcp
migratetype but whose tail is isolated. This means that in certain cases
memory can still be allocated after isolation. It will also trigger the
freelist type hygiene warnings in subsequent patches.
start_isolate_page_range()
isolate_single_pageblock()
set_migratetype_isolate(tail)
lock zone->lock
move_freepages_block(tail) // nop
set_pageblock_migratetype(tail)
unlock zone->lock
__rmqueue_smallest()
del_page_from_freelist(head)
expand(head, head_mt)
WARN(head_mt != tail_mt)
start_pfn = ALIGN_DOWN(MAX_ORDER_NR_PAGES)
for (pfn = start_pfn, pfn < end_pfn)
if (PageBuddy())
split_free_page(head)
Introduce a variant of move_freepages_block() provided by the allocator
specifically for page isolation; it moves free pages, converts the block,
and handles the splitting of straddling buddies while holding zone->lock.
The allocator knows that pageblocks and buddies are always naturally
aligned, which means that buddies can only straddle blocks if they're
actually >pageblock_order. This means the search-and-split part can be
simplified compared to what page isolation used to do.
Also tighten up the page isolation code around the expectations of which
pages can be large, and how they are freed.
Based on extensive discussions with and invaluable input from Zi Yan.
[hannes@cmpxchg.org: work around older gcc warning]
Link: https://lkml.kernel.org/r/20240321142426.GB777580@cmpxchg.org
Link: https://lkml.kernel.org/r/20240320180429.678181-10-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
This avoids changing migratetype after move_freepages() or
move_freepages_block(), which is error prone. It also prepares for
upcoming changes to fix move_freepages() not moving free pages partially
in the range.
Link: https://lkml.kernel.org/r/20240320180429.678181-9-hannes@cmpxchg.org
Signed-off-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
There are three freeing paths that read the page's migratetype
optimistically before grabbing the zone lock. When this races with block
stealing, those pages go on the wrong freelist.
The paths in question are:
- when freeing >costly orders that aren't THP
- when freeing pages to the buddy upon pcp lock contention
- when freeing pages that are isolated
- when freeing pages initially during boot
- when freeing the remainder in alloc_pages_exact()
- when "accepting" unaccepted VM host memory before first use
- when freeing pages during unpoisoning
None of these are so hot that they would need this optimization at the
cost of hampering defrag efforts. Especially when contrasted with the
fact that the most common buddy freeing path - free_pcppages_bulk - is
checking the migratetype under the zone->lock just fine.
In addition, isolated pages need to look up the migratetype under the lock
anyway, which adds branches to the locked section, and results in a double
lookup when the pages are in fact isolated.
Move the lookups into the lock.
Link: https://lkml.kernel.org/r/20240320180429.678181-8-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Currently, page block type conversion during fallbacks, atomic
reservations and isolation can strand various amounts of free pages on
incorrect freelists.
For example, fallback stealing moves free pages in the block to the new
type's freelists, but then may not actually claim the block for that type
if there aren't enough compatible pages already allocated.
In all cases, free page moving might fail if the block straddles more than
one zone, in which case no free pages are moved at all, but the block type
is changed anyway.
This is detrimental to type hygiene on the freelists. It encourages
incompatible page mixing down the line (ask for one type, get another) and
thus contributes to long-term fragmentation.
Split the process into a proper transaction: check first if conversion
will happen, then try to move the free pages, and only if that was
successful convert the block to the new type.
[baolin.wang@linux.alibaba.com: fix allocation failures with CONFIG_CMA]
Link: https://lkml.kernel.org/r/a97697e0-45b0-4f71-b087-fdc7a1d43c0e@linux.alibaba.com
Link: https://lkml.kernel.org/r/20240320180429.678181-7-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Tested-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
When a block is partially outside the zone of the cursor page, the
function cuts the range to the pivot page instead of the zone start. This
can leave large parts of the block behind, which encourages incompatible
page mixing down the line (ask for one type, get another), and thus
long-term fragmentation.
This triggers reliably on the first block in the DMA zone, whose start_pfn
is 1. The block is stolen, but everything before the pivot page (which
was often hundreds of pages) is left on the old list.
Link: https://lkml.kernel.org/r/20240320180429.678181-6-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
When claiming a block during compaction isolation, move any remaining free
pages to the correct freelists as well, instead of stranding them on the
wrong list. Otherwise, this encourages incompatible page mixing down the
line, and thus long-term fragmentation.
Link: https://lkml.kernel.org/r/20240320180429.678181-5-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Tested-by: "Huang, Ying" <ying.huang@intel.com>
Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The buddy allocator coalesces compatible blocks during freeing, but it
doesn't update the types of the subblocks to match. When an allocation
later breaks the chunk down again, its pieces will be put on freelists of
the wrong type. This encourages incompatible page mixing (ask for one
type, get another), and thus long-term fragmentation.
Update the subblocks when merging a larger chunk, such that a later
expand() will maintain freelist type hygiene.
Link: https://lkml.kernel.org/r/20240320180429.678181-4-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Tested-by: "Huang, Ying" <ying.huang@intel.com>
Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Move direct freeing of isolated pages to the lock-breaking block in the
second loop. This saves an unnecessary migratetype reassessment.
Minor comment and local variable scoping cleanups.
Link: https://lkml.kernel.org/r/20240320180429.678181-3-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Patch series "mm: page_alloc: freelist migratetype hygiene", v4.
The page allocator's mobility grouping is intended to keep unmovable pages
separate from reclaimable/compactable ones to allow on-demand
defragmentation for higher-order allocations and huge pages.
Currently, there are several places where accidental type mixing occurs:
an allocation asks for a page of a certain migratetype and receives
another. This ruins pageblocks for compaction, which in turn makes
allocating huge pages more expensive and less reliable.
The series addresses those causes. The last patch adds type checks on all
freelist movements to prevent new violations being introduced.
The benefits can be seen in a mixed workload that stresses the machine
with a memcache-type workload and a kernel build job while periodically
attempting to allocate batches of THP. The following data is aggregated
over 50 consecutive defconfig builds:
VANILLA PATCHED
Hugealloc Time mean 165843.93 ( +0.00%) 113025.88 ( -31.85%)
Hugealloc Time stddev 158957.35 ( +0.00%) 114716.07 ( -27.83%)
Kbuild Real time 310.24 ( +0.00%) 300.73 ( -3.06%)
Kbuild User time 1271.13 ( +0.00%) 1259.42 ( -0.92%)
Kbuild System time 582.02 ( +0.00%) 559.79 ( -3.81%)
THP fault alloc 30585.14 ( +0.00%) 40853.62 ( +33.57%)
THP fault fallback 36626.46 ( +0.00%) 26357.62 ( -28.04%)
THP fault fail rate % 54.49 ( +0.00%) 39.22 ( -27.53%)
Pagealloc fallback 1328.00 ( +0.00%) 1.00 ( -99.85%)
Pagealloc type mismatch 181009.50 ( +0.00%) 0.00 ( -100.00%)
Direct compact stall 434.56 ( +0.00%) 257.66 ( -40.61%)
Direct compact fail 421.70 ( +0.00%) 249.94 ( -40.63%)
Direct compact success 12.86 ( +0.00%) 7.72 ( -37.09%)
Direct compact success rate % 2.86 ( +0.00%) 2.82 ( -0.96%)
Compact daemon scanned migrate 3370059.62 ( +0.00%) 3612054.76 ( +7.18%)
Compact daemon scanned free 7718439.20 ( +0.00%) 5386385.02 ( -30.21%)
Compact direct scanned migrate 309248.62 ( +0.00%) 176721.04 ( -42.85%)
Compact direct scanned free 433582.84 ( +0.00%) 315727.66 ( -27.18%)
Compact migrate scanned daemon % 91.20 ( +0.00%) 94.48 ( +3.56%)
Compact free scanned daemon % 94.58 ( +0.00%) 94.42 ( -0.16%)
Compact total migrate scanned 3679308.24 ( +0.00%) 3788775.80 ( +2.98%)
Compact total free scanned 8152022.04 ( +0.00%) 5702112.68 ( -30.05%)
Alloc stall 872.04 ( +0.00%) 5156.12 ( +490.71%)
Pages kswapd scanned 510645.86 ( +0.00%) 3394.94 ( -99.33%)
Pages kswapd reclaimed 134811.62 ( +0.00%) 2701.26 ( -98.00%)
Pages direct scanned 99546.06 ( +0.00%) 376407.52 ( +278.12%)
Pages direct reclaimed 62123.40 ( +0.00%) 289535.70 ( +366.06%)
Pages total scanned 610191.92 ( +0.00%) 379802.46 ( -37.76%)
Pages scanned kswapd % 76.36 ( +0.00%) 0.10 ( -98.58%)
Swap out 12057.54 ( +0.00%) 15022.98 ( +24.59%)
Swap in 209.16 ( +0.00%) 256.48 ( +22.52%)
File refaults 17701.64 ( +0.00%) 11765.40 ( -33.53%)
Huge page success rate is higher, allocation latencies are shorter and
more predictable.
Stealing (fallback) rate is drastically reduced. Notably, while the
vanilla kernel keeps doing fallbacks on an ongoing basis, the patched
kernel enters a steady state once the distribution of block types is
adequate for the workload. Steals over 50 runs:
VANILLA PATCHED
1504.0 227.0
1557.0 6.0
1391.0 13.0
1080.0 26.0
1057.0 40.0
1156.0 6.0
805.0 46.0
736.0 20.0
1747.0 2.0
1699.0 34.0
1269.0 13.0
1858.0 12.0
907.0 4.0
727.0 2.0
563.0 2.0
3094.0 2.0
10211.0 3.0
2621.0 1.0
5508.0 2.0
1060.0 2.0
538.0 3.0
5773.0 2.0
2199.0 0.0
3781.0 2.0
1387.0 1.0
4977.0 0.0
2865.0 1.0
1814.0 1.0
3739.0 1.0
6857.0 0.0
382.0 0.0
407.0 1.0
3784.0 0.0
297.0 0.0
298.0 0.0
6636.0 0.0
4188.0 0.0
242.0 0.0
9960.0 0.0
5816.0 0.0
354.0 0.0
287.0 0.0
261.0 0.0
140.0 1.0
2065.0 0.0
312.0 0.0
331.0 0.0
164.0 0.0
465.0 1.0
219.0 0.0
Type mismatches are down too. Those count every time an allocation
request asks for one migratetype and gets another. This can still occur
minimally in the patched kernel due to non-stealing fallbacks, but it's
quite rare and follows the pattern of overall fallbacks - once the block
type distribution settles, mismatches cease as well:
VANILLA: PATCHED:
182602.0 268.0
135794.0 20.0
88619.0 19.0
95973.0 0.0
129590.0 0.0
129298.0 0.0
147134.0 0.0
230854.0 0.0
239709.0 0.0
137670.0 0.0
132430.0 0.0
65712.0 0.0
57901.0 0.0
67506.0 0.0
63565.0 4.0
34806.0 0.0
42962.0 0.0
32406.0 0.0
38668.0 0.0
61356.0 0.0
57800.0 0.0
41435.0 0.0
83456.0 0.0
65048.0 0.0
28955.0 0.0
47597.0 0.0
75117.0 0.0
55564.0 0.0
38280.0 0.0
52404.0 0.0
26264.0 0.0
37538.0 0.0
19671.0 0.0
30936.0 0.0
26933.0 0.0
16962.0 0.0
44554.0 0.0
46352.0 0.0
24995.0 0.0
35152.0 0.0
12823.0 0.0
21583.0 0.0
18129.0 0.0
31693.0 0.0
28745.0 0.0
33308.0 0.0
31114.0 0.0
35034.0 0.0
12111.0 0.0
24885.0 0.0
Compaction work is markedly reduced despite much better THP rates.
In the vanilla kernel, reclaim seems to have been driven primarily by
watermark boosting that happens as a result of fallbacks. With those all
but eliminated, watermarks average lower and kswapd does less work. The
uptick in direct reclaim is because THP requests have to fend for
themselves more often - which is intended policy right now. Aggregate
reclaim activity is lowered significantly, though.
This patch (of 10):
The idea behind the cache is to save get_pageblock_migratetype() lookups
during bulk freeing. A microbenchmark suggests this isn't helping,
though. The pcp migratetype can get stale, which means that bulk freeing
has an extra branch to check if the pageblock was isolated while on the
pcp.
While the variance overlaps, the cache write and the branch seem to make
this a net negative. The following test allocates and frees batches of
10,000 pages (~3x the pcp high marks to trigger flushing):
Before:
8,668.48 msec task-clock # 99.735 CPUs utilized ( +- 2.90% )
19 context-switches # 4.341 /sec ( +- 3.24% )
0 cpu-migrations # 0.000 /sec
17,440 page-faults # 3.984 K/sec ( +- 2.90% )
41,758,692,473 cycles # 9.541 GHz ( +- 2.90% )
126,201,294,231 instructions # 5.98 insn per cycle ( +- 2.90% )
25,348,098,335 branches # 5.791 G/sec ( +- 2.90% )
33,436,921 branch-misses # 0.26% of all branches ( +- 2.90% )
0.0869148 +- 0.0000302 seconds time elapsed ( +- 0.03% )
After:
8,444.81 msec task-clock # 99.726 CPUs utilized ( +- 2.90% )
22 context-switches # 5.160 /sec ( +- 3.23% )
0 cpu-migrations # 0.000 /sec
17,443 page-faults # 4.091 K/sec ( +- 2.90% )
40,616,738,355 cycles # 9.527 GHz ( +- 2.90% )
126,383,351,792 instructions # 6.16 insn per cycle ( +- 2.90% )
25,224,985,153 branches # 5.917 G/sec ( +- 2.90% )
32,236,793 branch-misses # 0.25% of all branches ( +- 2.90% )
0.0846799 +- 0.0000412 seconds time elapsed ( +- 0.05% )
A side effect is that this also ensures that pages whose pageblock gets
stolen while on the pcplist end up on the right freelist and we don't
perform potentially type-incompatible buddy merges (or skip merges when we
shouldn't), which is likely beneficial to long-term fragmentation
management, although the effects would be harder to measure. Settle for
simpler and faster code as justification here.
Link: https://lkml.kernel.org/r/20240320180429.678181-1-hannes@cmpxchg.org
Link: https://lkml.kernel.org/r/20240320180429.678181-2-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Tested-by: "Huang, Ying" <ying.huang@intel.com>
Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Patch series "Various significant MM patches".
These patches all interact in annoying ways which make it tricky to send
them out in any way other than a big batch, even though there's not really
an overarching theme to connect them.
The big effects of this patch series are:
- folio_test_hugetlb() becomes reliable, even when called without a
page reference
- We free up PG_slab, and we could always use more page flags
- We no longer need to check PageSlab before calling page_mapcount()
This patch (of 9):
For compound pages which are at least order-2 (and hence have a
deferred_list), initialise it and then we can check at free that the page
is not part of a deferred list. We recently found this useful to rule out
a source of corruption.
[peterx@redhat.com: always initialise folio->_deferred_list]
Link: https://lkml.kernel.org/r/20240417211836.2742593-2-peterx@redhat.com
Link: https://lkml.kernel.org/r/20240321142448.1645400-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20240321142448.1645400-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
When a non-compound multi-order page is freed, it is possible that a
speculative reference keeps the page pinned. In this case we free all
pages except for the first page, which will be freed later by the last
put_page(). However the page passed to put_page() is indistinguishable
from an order-0 page, so it cannot do the accounting, just as it cannot
free the subsequent pages. Do the accounting here, where we free the
pages.
Link: https://lkml.kernel.org/r/20240321163705.3067592-21-surenb@google.com
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Tested-by: Kees Cook <keescook@chromium.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Andreas Hindborg <a.hindborg@samsung.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Gary Guo <gary@garyguo.net>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
When a high-order page is split into smaller ones, each newly split page
should get its codetag. After the split each split page will be
referencing the original codetag. The codetag's "bytes" counter remains
the same because the amount of allocated memory has not changed, however
the "calls" counter gets increased to keep the counter correct when these
individual pages get freed.
Link: https://lkml.kernel.org/r/20240321163705.3067592-20-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Kees Cook <keescook@chromium.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Andreas Hindborg <a.hindborg@samsung.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Gary Guo <gary@garyguo.net>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Redefine page allocators to record allocation tags upon their invocation.
Instrument post_alloc_hook and free_pages_prepare to modify current
allocation tag.
[surenb@google.com: undo _noprof additions in the documentation]
Link: https://lkml.kernel.org/r/20240326231453.1206227-3-surenb@google.com
Link: https://lkml.kernel.org/r/20240321163705.3067592-19-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Co-developed-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Andreas Hindborg <a.hindborg@samsung.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Gary Guo <gary@garyguo.net>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Introduce helper functions to easily instrument page allocators by storing
a pointer to the allocation tag associated with the code that allocated
the page in a page_ext field.
Link: https://lkml.kernel.org/r/20240321163705.3067592-15-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Co-developed-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Kees Cook <keescook@chromium.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Andreas Hindborg <a.hindborg@samsung.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Gary Guo <gary@garyguo.net>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "mm/treewide: Remove pXd_huge() API", v2.
In previous work [1], we removed the pXd_large() API, which is arch
specific. This patchset further removes the hugetlb pXd_huge() API.
Hugetlb was never special on creating huge mappings when compared with
other huge mappings. Having a standalone API just to detect such pgtable
entries is more or less redundant, especially after the pXd_leaf() API set
is introduced with/without CONFIG_HUGETLB_PAGE.
When looking at this problem, a few issues are also exposed that we don't
have a clear definition of the *_huge() variance API. This patchset
started by cleaning these issues first, then replace all *_huge() users to
use *_leaf(), then drop all *_huge() code.
On x86/sparc, swap entries will be reported "true" in pXd_huge(), while
for all the rest archs they're reported "false" instead. This part is
done in patch 1-5, in which I suspect patch 1 can be seen as a bug fix,
but I'll leave that to hmm experts to decide.
Besides, there are three archs (arm, arm64, powerpc) that have slightly
different definitions between the *_huge() v.s. *_leaf() variances. I
tackled them separately so that it'll be easier for arch experts to chim
in when necessary. This part is done in patch 6-9.
The final patches 10-14 do the rest on the final removal, since *_leaf()
will be the ultimate API in the future, and we seem to have quite some
confusions on how *_huge() APIs can be defined, provide a rich comment for
*_leaf() API set to define them properly to avoid future misuse, and
hopefully that'll also help new archs to start support huge mappings and
avoid traps (like either swap entries, or PROT_NONE entry checks).
[1] https://lore.kernel.org/r/20240305043750.93762-1-peterx@redhat.com
This patch (of 14):
When the complete PCP is drained a much larger number of pages than the
usual batch size might be freed at once, causing large IRQ and preemption
latency spikes, as they are all freed while holding the pcp and zone
spinlocks.
To avoid those latency spikes, limit the number of pages freed in a single
bulk operation to common batch limits.
Link: https://lkml.kernel.org/r/20240318200404.448346-1-peterx@redhat.com
Link: https://lkml.kernel.org/r/20240318200736.2835502-1-l.stach@pengutronix.de
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bjorn Andersson <andersson@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Fabio Estevam <festevam@denx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Konrad Dybcio <konrad.dybcio@linaro.org>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- Sumanth Korikkar has taught s390 to allocate hotplug-time page frames
from hotplugged memory rather than only from main memory. Series
"implement "memmap on memory" feature on s390".
- More folio conversions from Matthew Wilcox in the series
"Convert memcontrol charge moving to use folios"
"mm: convert mm counter to take a folio"
- Chengming Zhou has optimized zswap's rbtree locking, providing
significant reductions in system time and modest but measurable
reductions in overall runtimes. The series is "mm/zswap: optimize the
scalability of zswap rb-tree".
- Chengming Zhou has also provided the series "mm/zswap: optimize zswap
lru list" which provides measurable runtime benefits in some
swap-intensive situations.
- And Chengming Zhou further optimizes zswap in the series "mm/zswap:
optimize for dynamic zswap_pools". Measured improvements are modest.
- zswap cleanups and simplifications from Yosry Ahmed in the series
"mm: zswap: simplify zswap_swapoff()".
- In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has
contributed several DAX cleanups as well as adding a sysfs tunable to
control the memmap_on_memory setting when the dax device is
hotplugged as system memory.
- Johannes Weiner has added the large series "mm: zswap: cleanups",
which does that.
- More DAMON work from SeongJae Park in the series
"mm/damon: make DAMON debugfs interface deprecation unignorable"
"selftests/damon: add more tests for core functionalities and corner cases"
"Docs/mm/damon: misc readability improvements"
"mm/damon: let DAMOS feeds and tame/auto-tune itself"
- In the series "mm/mempolicy: weighted interleave mempolicy and sysfs
extension" Rakie Kim has developed a new mempolicy interleaving
policy wherein we allocate memory across nodes in a weighted fashion
rather than uniformly. This is beneficial in heterogeneous memory
environments appearing with CXL.
- Christophe Leroy has contributed some cleanup and consolidation work
against the ARM pagetable dumping code in the series "mm: ptdump:
Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute".
- Luis Chamberlain has added some additional xarray selftesting in the
series "test_xarray: advanced API multi-index tests".
- Muhammad Usama Anjum has reworked the selftest code to make its
human-readable output conform to the TAP ("Test Anything Protocol")
format. Amongst other things, this opens up the use of third-party
tools to parse and process out selftesting results.
- Ryan Roberts has added fork()-time PTE batching of THP ptes in the
series "mm/memory: optimize fork() with PTE-mapped THP". Mainly
targeted at arm64, this significantly speeds up fork() when the
process has a large number of pte-mapped folios.
- David Hildenbrand also gets in on the THP pte batching game in his
series "mm/memory: optimize unmap/zap with PTE-mapped THP". It
implements batching during munmap() and other pte teardown
situations. The microbenchmark improvements are nice.
- And in the series "Transparent Contiguous PTEs for User Mappings"
Ryan Roberts further utilizes arm's pte's contiguous bit ("contpte
mappings"). Kernel build times on arm64 improved nicely. Ryan's
series "Address some contpte nits" provides some followup work.
- In the series "mm/hugetlb: Restore the reservation" Breno Leitao has
fixed an obscure hugetlb race which was causing unnecessary page
faults. He has also added a reproducer under the selftest code.
- In the series "selftests/mm: Output cleanups for the compaction
test", Mark Brown did what the title claims.
- Kinsey Ho has added the series "mm/mglru: code cleanup and
refactoring".
- Even more zswap material from Nhat Pham. The series "fix and extend
zswap kselftests" does as claimed.
- In the series "Introduce cpu_dcache_is_aliasing() to fix DAX
regression" Mathieu Desnoyers has cleaned up and fixed rather a mess
in our handling of DAX on archiecctures which have virtually aliasing
data caches. The arm architecture is the main beneficiary.
- Lokesh Gidra's series "per-vma locks in userfaultfd" provides
dramatic improvements in worst-case mmap_lock hold times during
certain userfaultfd operations.
- Some page_owner enhancements and maintenance work from Oscar Salvador
in his series
"page_owner: print stacks and their outstanding allocations"
"page_owner: Fixup and cleanup"
- Uladzislau Rezki has contributed some vmalloc scalability
improvements in his series "Mitigate a vmap lock contention". It
realizes a 12x improvement for a certain microbenchmark.
- Some kexec/crash cleanup work from Baoquan He in the series "Split
crash out from kexec and clean up related config items".
- Some zsmalloc maintenance work from Chengming Zhou in the series
"mm/zsmalloc: fix and optimize objects/page migration"
"mm/zsmalloc: some cleanup for get/set_zspage_mapping()"
- Zi Yan has taught the MM to perform compaction on folios larger than
order=0. This a step along the path to implementaton of the merging
of large anonymous folios. The series is named "Enable >0 order folio
memory compaction".
- Christoph Hellwig has done quite a lot of cleanup work in the
pagecache writeback code in his series "convert write_cache_pages()
to an iterator".
- Some modest hugetlb cleanups and speedups in Vishal Moola's series
"Handle hugetlb faults under the VMA lock".
- Zi Yan has changed the page splitting code so we can split huge pages
into sizes other than order-0 to better utilize large folios. The
series is named "Split a folio to any lower order folios".
- David Hildenbrand has contributed the series "mm: remove
total_mapcount()", a cleanup.
- Matthew Wilcox has sought to improve the performance of bulk memory
freeing in his series "Rearrange batched folio freeing".
- Gang Li's series "hugetlb: parallelize hugetlb page init on boot"
provides large improvements in bootup times on large machines which
are configured to use large numbers of hugetlb pages.
- Matthew Wilcox's series "PageFlags cleanups" does that.
- Qi Zheng's series "minor fixes and supplement for ptdesc" does that
also. S390 is affected.
- Cleanups to our pagemap utility functions from Peter Xu in his series
"mm/treewide: Replace pXd_large() with pXd_leaf()".
- Nico Pache has fixed a few things with our hugepage selftests in his
series "selftests/mm: Improve Hugepage Test Handling in MM
Selftests".
- Also, of course, many singleton patches to many things. Please see
the individual changelogs for details.
* tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (435 commits)
mm/zswap: remove the memcpy if acomp is not sleepable
crypto: introduce: acomp_is_async to expose if comp drivers might sleep
memtest: use {READ,WRITE}_ONCE in memory scanning
mm: prohibit the last subpage from reusing the entire large folio
mm: recover pud_leaf() definitions in nopmd case
selftests/mm: skip the hugetlb-madvise tests on unmet hugepage requirements
selftests/mm: skip uffd hugetlb tests with insufficient hugepages
selftests/mm: dont fail testsuite due to a lack of hugepages
mm/huge_memory: skip invalid debugfs new_order input for folio split
mm/huge_memory: check new folio order when split a folio
mm, vmscan: retry kswapd's priority loop with cache_trim_mode off on failure
mm: add an explicit smp_wmb() to UFFDIO_CONTINUE
mm: fix list corruption in put_pages_list
mm: remove folio from deferred split list before uncharging it
filemap: avoid unnecessary major faults in filemap_fault()
mm,page_owner: drop unnecessary check
mm,page_owner: check for null stack_record before bumping its refcount
mm: swap: fix race between free_swap_and_cache() and swapoff()
mm/treewide: align up pXd_leaf() retval across archs
mm/treewide: drop pXd_large()
...
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git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from Jakub Kicinski:
"Core & protocols:
- Large effort by Eric to lower rtnl_lock pressure and remove locks:
- Make commonly used parts of rtnetlink (address, route dumps
etc) lockless, protected by RCU instead of rtnl_lock.
- Add a netns exit callback which already holds rtnl_lock,
allowing netns exit to take rtnl_lock once in the core instead
of once for each driver / callback.
- Remove locks / serialization in the socket diag interface.
- Remove 6 calls to synchronize_rcu() while holding rtnl_lock.
- Remove the dev_base_lock, depend on RCU where necessary.
- Support busy polling on a per-epoll context basis. Poll length and
budget parameters can be set independently of system defaults.
- Introduce struct net_hotdata, to make sure read-mostly global
config variables fit in as few cache lines as possible.
- Add optional per-nexthop statistics to ease monitoring / debug of
ECMP imbalance problems.
- Support TCP_NOTSENT_LOWAT in MPTCP.
- Ensure that IPv6 temporary addresses' preferred lifetimes are long
enough, compared to other configured lifetimes, and at least 2 sec.
- Support forwarding of ICMP Error messages in IPSec, per RFC 4301.
- Add support for the independent control state machine for bonding
per IEEE 802.1AX-2008 5.4.15 in addition to the existing coupled
control state machine.
- Add "network ID" to MCTP socket APIs to support hosts with multiple
disjoint MCTP networks.
- Re-use the mono_delivery_time skbuff bit for packets which user
space wants to be sent at a specified time. Maintain the timing
information while traversing veth links, bridge etc.
- Take advantage of MSG_SPLICE_PAGES for RxRPC DATA and ACK packets.
- Simplify many places iterating over netdevs by using an xarray
instead of a hash table walk (hash table remains in place, for use
on fastpaths).
- Speed up scanning for expired routes by keeping a dedicated list.
- Speed up "generic" XDP by trying harder to avoid large allocations.
- Support attaching arbitrary metadata to netconsole messages.
Things we sprinkled into general kernel code:
- Enforce VM_IOREMAP flag and range in ioremap_page_range and
introduce VM_SPARSE kind and vm_area_[un]map_pages (used by
bpf_arena).
- Rework selftest harness to enable the use of the full range of ksft
exit code (pass, fail, skip, xfail, xpass).
Netfilter:
- Allow userspace to define a table that is exclusively owned by a
daemon (via netlink socket aliveness) without auto-removing this
table when the userspace program exits. Such table gets marked as
orphaned and a restarting management daemon can re-attach/regain
ownership.
- Speed up element insertions to nftables' concatenated-ranges set
type. Compact a few related data structures.
BPF:
- Add BPF token support for delegating a subset of BPF subsystem
functionality from privileged system-wide daemons such as systemd
through special mount options for userns-bound BPF fs to a trusted
& unprivileged application.
- Introduce bpf_arena which is sparse shared memory region between
BPF program and user space where structures inside the arena can
have pointers to other areas of the arena, and pointers work
seamlessly for both user-space programs and BPF programs.
- Introduce may_goto instruction that is a contract between the
verifier and the program. The verifier allows the program to loop
assuming it's behaving well, but reserves the right to terminate
it.
- Extend the BPF verifier to enable static subprog calls in spin lock
critical sections.
- Support registration of struct_ops types from modules which helps
projects like fuse-bpf that seeks to implement a new struct_ops
type.
- Add support for retrieval of cookies for perf/kprobe multi links.
- Support arbitrary TCP SYN cookie generation / validation in the TC
layer with BPF to allow creating SYN flood handling in BPF
firewalls.
- Add code generation to inline the bpf_kptr_xchg() helper which
improves performance when stashing/popping the allocated BPF
objects.
Wireless:
- Add SPP (signaling and payload protected) AMSDU support.
- Support wider bandwidth OFDMA, as required for EHT operation.
Driver API:
- Major overhaul of the Energy Efficient Ethernet internals to
support new link modes (2.5GE, 5GE), share more code between
drivers (especially those using phylib), and encourage more
uniform behavior. Convert and clean up drivers.
- Define an API for querying per netdev queue statistics from
drivers.
- IPSec: account in global stats for fully offloaded sessions.
- Create a concept of Ethernet PHY Packages at the Device Tree level,
to allow parameterizing the existing PHY package code.
- Enable Rx hashing (RSS) on GTP protocol fields.
Misc:
- Improvements and refactoring all over networking selftests.
- Create uniform module aliases for TC classifiers, actions, and
packet schedulers to simplify creating modprobe policies.
- Address all missing MODULE_DESCRIPTION() warnings in networking.
- Extend the Netlink descriptions in YAML to cover message
encapsulation or "Netlink polymorphism", where interpretation of
nested attributes depends on link type, classifier type or some
other "class type".
Drivers:
- Ethernet high-speed NICs:
- Add a new driver for Marvell's Octeon PCI Endpoint NIC VF.
- Intel (100G, ice, idpf):
- support E825-C devices
- nVidia/Mellanox:
- support devices with one port and multiple PCIe links
- Broadcom (bnxt):
- support n-tuple filters
- support configuring the RSS key
- Wangxun (ngbe/txgbe):
- implement irq_domain for TXGBE's sub-interrupts
- Pensando/AMD:
- support XDP
- optimize queue submission and wakeup handling (+17% bps)
- optimize struct layout, saving 28% of memory on queues
- Ethernet NICs embedded and virtual:
- Google cloud vNIC:
- refactor driver to perform memory allocations for new queue
config before stopping and freeing the old queue memory
- Synopsys (stmmac):
- obey queueMaxSDU and implement counters required by 802.1Qbv
- Renesas (ravb):
- support packet checksum offload
- suspend to RAM and runtime PM support
- Ethernet switches:
- nVidia/Mellanox:
- support for nexthop group statistics
- Microchip:
- ksz8: implement PHY loopback
- add support for KSZ8567, a 7-port 10/100Mbps switch
- PTP:
- New driver for RENESAS FemtoClock3 Wireless clock generator.
- Support OCP PTP cards designed and built by Adva.
- CAN:
- Support recvmsg() flags for own, local and remote traffic on CAN
BCM sockets.
- Support for esd GmbH PCIe/402 CAN device family.
- m_can:
- Rx/Tx submission coalescing
- wake on frame Rx
- WiFi:
- Intel (iwlwifi):
- enable signaling and payload protected A-MSDUs
- support wider-bandwidth OFDMA
- support for new devices
- bump FW API to 89 for AX devices; 90 for BZ/SC devices
- MediaTek (mt76):
- mt7915: newer ADIE version support
- mt7925: radio temperature sensor support
- Qualcomm (ath11k):
- support 6 GHz station power modes: Low Power Indoor (LPI),
Standard Power) SP and Very Low Power (VLP)
- QCA6390 & WCN6855: support 2 concurrent station interfaces
- QCA2066 support
- Qualcomm (ath12k):
- refactoring in preparation for Multi-Link Operation (MLO)
support
- 1024 Block Ack window size support
- firmware-2.bin support
- support having multiple identical PCI devices (firmware needs
to have ATH12K_FW_FEATURE_MULTI_QRTR_ID)
- QCN9274: support split-PHY devices
- WCN7850: enable Power Save Mode in station mode
- WCN7850: P2P support
- RealTek:
- rtw88: support for more rtw8811cu and rtw8821cu devices
- rtw89: support SCAN_RANDOM_SN and SET_SCAN_DWELL
- rtlwifi: speed up USB firmware initialization
- rtwl8xxxu:
- RTL8188F: concurrent interface support
- Channel Switch Announcement (CSA) support in AP mode
- Broadcom (brcmfmac):
- per-vendor feature support
- per-vendor SAE password setup
- DMI nvram filename quirk for ACEPC W5 Pro"
* tag 'net-next-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2255 commits)
nexthop: Fix splat with CONFIG_DEBUG_PREEMPT=y
nexthop: Fix out-of-bounds access during attribute validation
nexthop: Only parse NHA_OP_FLAGS for dump messages that require it
nexthop: Only parse NHA_OP_FLAGS for get messages that require it
bpf: move sleepable flag from bpf_prog_aux to bpf_prog
bpf: hardcode BPF_PROG_PACK_SIZE to 2MB * num_possible_nodes()
selftests/bpf: Add kprobe multi triggering benchmarks
ptp: Move from simple ida to xarray
vxlan: Remove generic .ndo_get_stats64
vxlan: Do not alloc tstats manually
devlink: Add comments to use netlink gen tool
nfp: flower: handle acti_netdevs allocation failure
net/packet: Add getsockopt support for PACKET_COPY_THRESH
net/netlink: Add getsockopt support for NETLINK_LISTEN_ALL_NSID
selftests/bpf: Add bpf_arena_htab test.
selftests/bpf: Add bpf_arena_list test.
selftests/bpf: Add unit tests for bpf_arena_alloc/free_pages
bpf: Add helper macro bpf_addr_space_cast()
libbpf: Recognize __arena global variables.
bpftool: Recognize arena map type
...
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Fixes Coccinelle/coccicheck warning reported by do_div.cocci.
Compared to do_div(), div64_ul() does not implicitly cast the divisor and
does not unnecessarily calculate the remainder.
Link: https://lkml.kernel.org/r/20240228224911.1164-2-thorsten.blum@toblux.com
Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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When draining a page_frag_cache, most user are doing
the similar steps, so introduce an API to avoid code
duplication.
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Currently there seems to be three page frag implementations
which all try to allocate order 3 page, if that fails, it
then fail back to allocate order 0 page, and each of them
all allow order 3 page allocation to fail under certain
condition by using specific gfp bits.
The gfp bits for order 3 page allocation are different
between different implementation, __GFP_NOMEMALLOC is
or'd to forbid access to emergency reserves memory for
__page_frag_cache_refill(), but it is not or'd in other
implementions, __GFP_DIRECT_RECLAIM is masked off to avoid
direct reclaim in vhost_net_page_frag_refill(), but it is
not masked off in __page_frag_cache_refill().
This patch unifies the gfp bits used between different
implementions by or'ing __GFP_NOMEMALLOC and masking off
__GFP_DIRECT_RECLAIM for order 3 page allocation to avoid
possible pressure for mm.
Leave the gfp unifying for page frag implementation in sock.c
for now as suggested by Paolo Abeni.
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
CC: Alexander Duyck <alexander.duyck@gmail.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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napi_alloc_frag_align() and netdev_alloc_frag_align() accept
align as an argument, and they are thin wrappers around the
__napi_alloc_frag_align() and __netdev_alloc_frag_align() APIs
doing the alignment checking and align mask conversion, in order
to call page_frag_alloc_align() directly. The intention here is
to keep the alignment checking and the alignmask conversion in
in-line wrapper to avoid those kind of operations during execution
time since it can usually be handled during compile time.
We are going to use page_frag_alloc_align() in vhost_net.c, it
need the same kind of alignment checking and alignmask conversion,
so split up page_frag_alloc_align into an inline wrapper doing the
above operation, and add __page_frag_alloc_align() which is passed
with the align mask the original function expected as suggested by
Alexander.
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
CC: Alexander Duyck <alexander.duyck@gmail.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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alloc_contig_migrate_range has every information to be able to understand
big contiguous allocation latency. For example, how many pages are
migrated, how many times they were needed to unmap from page tables.
This patch adds the trace event to collect the allocation statistics. In
the field, it was quite useful to understand CMA allocation latency.
[akpm@linux-foundation.org: a/trace_mm_alloc_config_migrate_range_info_enabled/trace_mm_alloc_contig_migrate_range_info_enabled]
Link: https://lkml.kernel.org/r/20240228051127.2859472-1-richardycc@google.com
Signed-off-by: Richard Chang <richardycc@google.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org.
Cc: Martin Liu <liumartin@google.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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All callers now use free_unref_folios() so we can delete this function.
Link: https://lkml.kernel.org/r/20240227174254.710559-15-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Call folio_undo_large_rmappable() if needed. free_unref_page_prepare()
destroys the ability to call folio_order(), so stash the order in
folio->private for the benefit of the second loop.
Link: https://lkml.kernel.org/r/20240227174254.710559-10-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Iterate over a folio_batch rather than a linked list. This is easier for
the CPU to prefetch and has a batch count naturally built in so we don't
need to track it. Again, this lowers the maximum lock hold time from
32 folios to 15, but I do not expect this to have a significant effect.
Link: https://lkml.kernel.org/r/20240227174254.710559-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Most of its callees are not yet ready to accept a folio, but we know all
of the pages passed in are actually folios because they're linked through
->lru.
Link: https://lkml.kernel.org/r/20240227174254.710559-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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It adds a new_order parameter to set new page order in page owner. It
prepares for upcoming changes to support split huge page to any lower
order.
Link: https://lkml.kernel.org/r/20240226205534.1603748-7-zi.yan@sent.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michal Koutny <mkoutny@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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It sets memcg information for the pages after the split. A new parameter
new_order is added to tell the order of subpages in the new page, always 0
for now. It prepares for upcoming changes to support split huge page to
any lower order.
Link: https://lkml.kernel.org/r/20240226205534.1603748-6-zi.yan@sent.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michal Koutny <mkoutny@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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We do not have non power of two pages, using nr is error prone if nr is
not power-of-two. Use page order instead.
Link: https://lkml.kernel.org/r/20240226205534.1603748-5-zi.yan@sent.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michal Koutny <mkoutny@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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We do not have non power of two pages, using nr is error prone if nr is
not power-of-two. Use page order instead.
Link: https://lkml.kernel.org/r/20240226205534.1603748-4-zi.yan@sent.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michal Koutny <mkoutny@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Make check_new_page() return bool like check_new_pages()
Link: https://lkml.kernel.org/r/20240222091932.54799-1-gehao@kylinos.cn
Signed-off-by: Hao Ge <gehao@kylinos.cn>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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allocations
Sven reports an infinite loop in __alloc_pages_slowpath() for costly order
__GFP_RETRY_MAYFAIL allocations that are also GFP_NOIO. Such combination
can happen in a suspend/resume context where a GFP_KERNEL allocation can
have __GFP_IO masked out via gfp_allowed_mask.
Quoting Sven:
1. try to do a "costly" allocation (order > PAGE_ALLOC_COSTLY_ORDER)
with __GFP_RETRY_MAYFAIL set.
2. page alloc's __alloc_pages_slowpath tries to get a page from the
freelist. This fails because there is nothing free of that costly
order.
3. page alloc tries to reclaim by calling __alloc_pages_direct_reclaim,
which bails out because a zone is ready to be compacted; it pretends
to have made a single page of progress.
4. page alloc tries to compact, but this always bails out early because
__GFP_IO is not set (it's not passed by the snd allocator, and even
if it were, we are suspending so the __GFP_IO flag would be cleared
anyway).
5. page alloc believes reclaim progress was made (because of the
pretense in item 3) and so it checks whether it should retry
compaction. The compaction retry logic thinks it should try again,
because:
a) reclaim is needed because of the early bail-out in item 4
b) a zonelist is suitable for compaction
6. goto 2. indefinite stall.
(end quote)
The immediate root cause is confusing the COMPACT_SKIPPED returned from
__alloc_pages_direct_compact() (step 4) due to lack of __GFP_IO to be
indicating a lack of order-0 pages, and in step 5 evaluating that in
should_compact_retry() as a reason to retry, before incrementing and
limiting the number of retries. There are however other places that
wrongly assume that compaction can happen while we lack __GFP_IO.
To fix this, introduce gfp_compaction_allowed() to abstract the __GFP_IO
evaluation and switch the open-coded test in try_to_compact_pages() to use
it.
Also use the new helper in:
- compaction_ready(), which will make reclaim not bail out in step 3, so
there's at least one attempt to actually reclaim, even if chances are
small for a costly order
- in_reclaim_compaction() which will make should_continue_reclaim()
return false and we don't over-reclaim unnecessarily
- in __alloc_pages_slowpath() to set a local variable can_compact,
which is then used to avoid retrying reclaim/compaction for costly
allocations (step 5) if we can't compact and also to skip the early
compaction attempt that we do in some cases
Link: https://lkml.kernel.org/r/20240221114357.13655-2-vbabka@suse.cz
Fixes: 3250845d0526 ("Revert "mm, oom: prevent premature OOM killer invocation for high order request"")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: Sven van Ashbrook <svenva@chromium.org>
Closes: https://lore.kernel.org/all/CAG-rBihs_xMKb3wrMO1%2B-%2Bp4fowP9oy1pa_OTkfxBzPUVOZF%2Bg@mail.gmail.com/
Tested-by: Karthikeyan Ramasubramanian <kramasub@chromium.org>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Curtis Malainey <cujomalainey@chromium.org>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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bad_range() can return bool, so let us change it.
Link: https://lkml.kernel.org/r/20240221073227.276234-1-gehao@kylinos.cn
Signed-off-by: Hao Ge <gehao@kylinos.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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