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The !CONFIG_THP_SWAP check existed before just fine because slot cache
would reject high order allocation and let the caller split all folios and
try again.
But slot cache is gone, so large allocation will directly go to the
allocator, and the allocator should just fail silently to inform caller to
do the folio split, this is totally fine and expected.
Remove this meaningless warning.
Link: https://lkml.kernel.org/r/20250429094803.85518-1-ryncsn@gmail.com
Fixes: 0ff67f990bd4 ("mm, swap: remove swap slot cache")
Signed-off-by: Kairui Song <kasong@tencent.com>
Reported-by: Heiko Carstens <hca@linux.ibm.com>
Closes: https://lore.kernel.org/linux-mm/20250428135252.25453B17-hca@linux.ibm.com/
Tested-by: Heiko Carstens <hca@linux.ibm.com>
Cc: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Introduce struct vm_struct::requested_size so that the requested
(re)allocation size is retained separately from the allocated area size.
This means that KASAN will correctly poison the correct spans of requested
bytes. This also means we can support growing the usable portion of an
allocation that can already be supported by the existing area's existing
allocation.
Link: https://lkml.kernel.org/r/20250426001105.it.679-kees@kernel.org
Fixes: 3ddc2fefe6f3 ("mm: vmalloc: implement vrealloc()")
Signed-off-by: Kees Cook <kees@kernel.org>
Reported-by: Erhard Furtner <erhard_f@mailbox.org>
Closes: https://lore.kernel.org/all/20250408192503.6149a816@outsider.home/
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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When migrating a THP, concurrent access to the PMD migration entry during
a deferred split scan can lead to an invalid address access, as
illustrated below. To prevent this invalid access, it is necessary to
check the PMD migration entry and return early. In this context, there is
no need to use pmd_to_swp_entry and pfn_swap_entry_to_page to verify the
equality of the target folio. Since the PMD migration entry is locked, it
cannot be served as the target.
Mailing list discussion and explanation from Hugh Dickins: "An anon_vma
lookup points to a location which may contain the folio of interest, but
might instead contain another folio: and weeding out those other folios is
precisely what the "folio != pmd_folio((*pmd)" check (and the "risk of
replacing the wrong folio" comment a few lines above it) is for."
BUG: unable to handle page fault for address: ffffea60001db008
CPU: 0 UID: 0 PID: 2199114 Comm: tee Not tainted 6.14.0+ #4 NONE
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:split_huge_pmd_locked+0x3b5/0x2b60
Call Trace:
<TASK>
try_to_migrate_one+0x28c/0x3730
rmap_walk_anon+0x4f6/0x770
unmap_folio+0x196/0x1f0
split_huge_page_to_list_to_order+0x9f6/0x1560
deferred_split_scan+0xac5/0x12a0
shrinker_debugfs_scan_write+0x376/0x470
full_proxy_write+0x15c/0x220
vfs_write+0x2fc/0xcb0
ksys_write+0x146/0x250
do_syscall_64+0x6a/0x120
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The bug is found by syzkaller on an internal kernel, then confirmed on
upstream.
Link: https://lkml.kernel.org/r/20250421113536.3682201-1-gavinguo@igalia.com
Link: https://lore.kernel.org/all/20250414072737.1698513-1-gavinguo@igalia.com/
Link: https://lore.kernel.org/all/20250418085802.2973519-1-gavinguo@igalia.com/
Fixes: 84c3fc4e9c56 ("mm: thp: check pmd migration entry in common path")
Signed-off-by: Gavin Guo <gavinguo@igalia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Cc: Florent Revest <revest@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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set_high_memory() touches arch_zone_lowest_possible_pfn which is
marked as __initdata, which creates a section mismatch.
Since the only user of the function is free_area_init() which is also marked
as __init, mark set_high_memory() as __init as well.
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202505060901.Qcs06UoB-lkp@intel.com/
Link: https://lore.kernel.org/r/20250506111012.108743-1-osalvador@suse.de
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
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Devices which have a requirement for bs > ps cannot be supported for
swap as swap still needs work. Now that the block device cache sets the
min order for block devices we need this stop gap otherwise all
swap operations are rejected.
Without this you'll end up with errors on these devices as the swap
code still needs much love to support min order.
With this we at least now put a stop gap of its use, until the
swap subsystem completes its major overhaul:
mkswap: /dev/nvme3n1: warning: wiping old swap signature.
Setting up swapspace version 1, size = 100 GiB (107374178304 bytes)
no label, UUID=6af76b5c-7e7b-4902-b7f7-4c24dde6fa36
swapon: /dev/nvme3n1: swapon failed: Invalid argument
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/aBkS926thy9zvdZb@bombadil.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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The stat is always 0 now, so remove it and hardwire the user visible
output to 0.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20250505081138.3435992-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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To enable node specific hash-tables using huge pages if possible.
[bigeasy: use __vmalloc_node_range_noprof(), add nommu bits, inline
vmalloc_huge]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250416162921.513656-3-bigeasy@linutronix.de
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git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab
Pull slab fix from Vlastimil Babka:
- Stable fix to avoid bugs due to leftover obj_ext after allocation
profiling is disabled at runtime (Zhenhua Huang)
* tag 'slab-for-6.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
mm, slab: clean up slab->obj_exts always
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Cross-merge networking fixes after downstream PR (net-6.15-rc5).
No conflicts or adjacent changes.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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gcc-12 and higher support the -ftrivial-auto-var-init= flag, after
gcc-8 is the minimum version, this is half of the supported ones, and
the vast majority of the versions that users are actually likely to
have, so it seems like a good time to stop having the fallback
plugin implementation
Older toolchains are still able to build kernels normally without
this plugin, but won't be able to use variable initialization..
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock
Pull memblock fixes from Mike Rapoport:
"Fixes for nid setting in memmap_init_reserved_pages():
- pass 'size' rather than 'end' to memblock_set_node() as that
function expects
- fix a corner case when memblock.reserved is doubled at
memmap_init_reserved_pages() and the newly reserved block
won't have nid assigned"
* tag 'fixes-2025-04-29' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
memblock tests: add test for memblock_set_node
mm/memblock: repeat setting reserved region nid if array is doubled
mm/memblock: pass size instead of end to memblock_set_node()
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Cross-merge networking fixes after downstream PR (net-6.15-rc4).
This pull includes wireless and a fix to vxlan which isn't
in Linus's tree just yet. The latter creates with a silent conflict
/ build breakage, so merging it now to avoid causing problems.
drivers/net/vxlan/vxlan_vnifilter.c
094adad91310 ("vxlan: Use a single lock to protect the FDB table")
087a9eb9e597 ("vxlan: vnifilter: Fix unlocked deletion of default FDB entry")
https://lore.kernel.org/20250423145131.513029-1-idosch@nvidia.com
No "normal" conflicts, or adjacent changes.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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When memory allocation profiling is disabled at runtime or due to an
error, shutdown_mem_profiling() is called: slab->obj_exts which
previously allocated remains.
It won't be cleared by unaccount_slab() because of
mem_alloc_profiling_enabled() not true. It's incorrect, slab->obj_exts
should always be cleaned up in unaccount_slab() to avoid following error:
[...]BUG: Bad page state in process...
..
[...]page dumped because: page still charged to cgroup
[andriy.shevchenko@linux.intel.com: fold need_slab_obj_ext() into its only user]
Fixes: 21c690a349ba ("mm: introduce slabobj_ext to support slab object extensions")
Cc: stable@vger.kernel.org
Signed-off-by: Zhenhua Huang <quic_zhenhuah@quicinc.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Harry Yoo <harry.yoo@oracle.com>
Tested-by: Harry Yoo <harry.yoo@oracle.com>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Link: https://patch.msgid.link/20250421075232.2165527-1-quic_zhenhuah@quicinc.com
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
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The large folio + buffer head noref migration scenarios are
being naughty and blocking while holding a spinlock.
As a consequence of the pagecache lookup path taking the
folio lock this serializes against migration paths, so
they can wait for each other. For the private_lock
atomic case, a new BH_Migrate flag is introduced which
enables the lookup to bail.
This allows the critical region of the private_lock on
the migration path to be reduced to the way it was before
ebdf4de5642fb6 ("mm: migrate: fix reference check race
between __find_get_block() and migration"), that is covering
the count checks.
The scope is always noref migration.
Reported-by: kernel test robot <oliver.sang@intel.com>
Reported-by: syzbot+f3c6fda1297c748a7076@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/oe-lkp/202503101536.27099c77-lkp@intel.com
Fixes: 3c20917120ce61 ("block/bdev: enable large folio support for large logical block sizes")
Reviewed-by: Jan Kara <jack@suse.cz>
Co-developed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Link: https://kdevops.org/ext4/v6.15-rc2.html # [0]
Link: https://lore.kernel.org/all/aAAEvcrmREWa1SKF@bombadil.infradead.org/ # [1]
Link: https://lore.kernel.org/20250418015921.132400-8-dave@stgolabs.net
Tested-by: kdevops@lists.linux.dev # [0] [1]
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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There are users like xfs which need larger allocations with NOFAIL
sementic. They are not using kvmalloc currently because the current
implementation tries too hard to allocate through the kmalloc path
which causes a lot of direct reclaim and compaction and that hurts
performance a lot (see 8dc9384b7d75 ("xfs: reduce kvmalloc overhead for
CIL shadow buffers") for more details).
kvmalloc does support __GFP_RETRY_MAYFAIL semantic to express that
kmalloc (physically contiguous) allocation is preferred and we should go
more aggressive to make it happen. There is currently no way to express
that kmalloc should be very lightweight and as it has been argued [1]
this mode should be default to support kvmalloc(NOFAIL) with a
lightweight kmalloc path which is currently impossible to express as
__GFP_NOFAIL cannot be combined by any other reclaim modifiers.
This patch makes all kmalloc allocations GFP_NOWAIT unless
__GFP_RETRY_MAYFAIL is provided to kvmalloc. This allows to support both
fail fast and retry hard on physically contiguous memory with vmalloc
fallback.
There is a potential downside that relatively small allocations (smaller
than PAGE_ALLOC_COSTLY_ORDER) could fallback to vmalloc too easily and
cause page block fragmentation. We cannot really rule that out but it
seems that xlog_cil_kvmalloc use doesn't indicate this to be happening.
[1] https://lore.kernel.org/all/Z-3i1wATGh6vI8x8@dread.disaster.area/T/#u
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Link: https://patch.msgid.link/Z-48K0OdNxZXcnkB@tiehlicka
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
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This makes it easy to detect proper anonymous inodes and to ensure that
we can detect them in codepaths such as readahead().
Readahead on anonymous inodes didn't work because they didn't have a
proper mode. Now that they have we need to retain EINVAL being returned
otherwise LTP will fail.
We also need to ensure that ioctls aren't simply fired like they are for
regular files so things like inotify inodes continue to correctly call
their own ioctl handlers as in [1].
Reported-by: Xilin Wu <sophon@radxa.com>
Link: https://lore.kernel.org/3A9139D5CD543962+89831381-31b9-4392-87ec-a84a5b3507d8@radxa.com [1]
Link: https://lore.kernel.org/7a1a7076-ff6b-4cb0-94e7-7218a0a44028@sirena.org.uk
Signed-off-by: Christian Brauner <brauner@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc hotfixes from Andrew Morton:
"16 hotfixes. 2 are cc:stable and the remainder address post-6.14
issues or aren't considered necessary for -stable kernels.
All patches are basically for MM although five are alterations to
MAINTAINERS"
[ Basic counting skills are clearly not a strictly necessary requirement
for kernel maintainers. - Linus ]
* tag 'mm-hotfixes-stable-2025-04-19-21-24' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
MAINTAINERS: add section for locking of mm's and VMAs
mm: vmscan: fix kswapd exit condition in defrag_mode
mm: vmscan: restore high-cpu watermark safety in kswapd
MAINTAINERS: add Pedro as reviewer to the MEMORY MAPPING section
mm/memory: move sanity checks in do_wp_page() after mapcount vs. refcount stabilization
mm, hugetlb: increment the number of pages to be reset on HVO
writeback: fix false warning in inode_to_wb()
docs: ABI: replace mcroce@microsoft.com with new Meta address
mm/gup: fix wrongly calculated returned value in fault_in_safe_writeable()
MAINTAINERS: add memory advice section
MAINTAINERS: add mmap trace events to MEMORY MAPPING
mm: memcontrol: fix swap counter leak from offline cgroup
MAINTAINERS: add MM subsection for the page allocator
MAINTAINERS: update SLAB ALLOCATOR maintainers
fs/dax: fix folio splitting issue by resetting old folio order + _nr_pages
mm/page_alloc: fix deadlock on cpu_hotplug_lock in __accept_page()
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git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull hardening fixes from Kees Cook:
- lib/prime_numbers: KUnit test should not select PRIME_NUMBERS (Geert
Uytterhoeven)
- ubsan: Fix panic from test_ubsan_out_of_bounds (Mostafa Saleh)
- ubsan: Remove 'default UBSAN' from UBSAN_INTEGER_WRAP (Nathan
Chancellor)
- string: Add load_unaligned_zeropad() code path to sized_strscpy()
(Peter Collingbourne)
- kasan: Add strscpy() test to trigger tag fault on arm64 (Vincenzo
Frascino)
- Disable GCC randstruct for COMPILE_TEST
* tag 'hardening-v6.15-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
lib/prime_numbers: KUnit test should not select PRIME_NUMBERS
ubsan: Fix panic from test_ubsan_out_of_bounds
lib/Kconfig.ubsan: Remove 'default UBSAN' from UBSAN_INTEGER_WRAP
hardening: Disable GCC randstruct for COMPILE_TEST
kasan: Add strscpy() test to trigger tag fault on arm64
string: Add load_unaligned_zeropad() code path to sized_strscpy()
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Vlastimil points out an issue with kswapd in defrag_mode not waking up
kcompactd reliably.
Background: When kswapd is woken for any higher-order request, it
initially checks those high-order watermarks to decide if work is
necesary. However, it cannot (efficiently) meet the contiguity goal of
such a request by itself. So once it has reclaimed a compaction gap, it
adjusts the request down to check for free order-0 pages, then wakes
kcompactd to coalesce them into larger blocks.
In defrag_mode, the initial watermark check needs to be analogously
against free pageblocks. However, once kswapd drops the high-order to
hand off contiguity work, it also needs to fall back to base page
watermarks - otherwise it'll keep reclaiming until blocks are freed.
While it appears kcompactd is woken up frequently enough to do most of the
compaction work, kswapd ends up overreclaiming by quite a bit:
DEFRAGMODE DEFRAGMODE-thispatch
Hugealloc Time mean 79381.34 ( +0.00%) 88126.12 ( +11.02%)
Hugealloc Time stddev 85852.16 ( +0.00%) 135366.75 ( +57.67%)
Kbuild Real time 249.35 ( +0.00%) 226.71 ( -9.04%)
Kbuild User time 1249.16 ( +0.00%) 1249.37 ( +0.02%)
Kbuild System time 171.76 ( +0.00%) 166.93 ( -2.79%)
THP fault alloc 51666.87 ( +0.00%) 52685.60 ( +1.97%)
THP fault fallback 16970.00 ( +0.00%) 15951.87 ( -6.00%)
Direct compact fail 166.53 ( +0.00%) 178.93 ( +7.40%)
Direct compact success 17.13 ( +0.00%) 4.13 ( -71.69%)
Compact daemon scanned migrate 3095413.33 ( +0.00%) 9231239.53 ( +198.22%)
Compact daemon scanned free 2155966.53 ( +0.00%) 7053692.87 ( +227.17%)
Compact direct scanned migrate 265642.47 ( +0.00%) 68388.33 ( -74.26%)
Compact direct scanned free 130252.60 ( +0.00%) 55634.87 ( -57.29%)
Compact total migrate scanned 3361055.80 ( +0.00%) 9299627.87 ( +176.69%)
Compact total free scanned 2286219.13 ( +0.00%) 7109327.73 ( +210.96%)
Alloc stall 1890.80 ( +0.00%) 6297.60 ( +232.94%)
Pages kswapd scanned 9043558.80 ( +0.00%) 5952576.73 ( -34.18%)
Pages kswapd reclaimed 1891708.67 ( +0.00%) 1030645.00 ( -45.52%)
Pages direct scanned 1017090.60 ( +0.00%) 2688047.60 ( +164.29%)
Pages direct reclaimed 92682.60 ( +0.00%) 309770.53 ( +234.22%)
Pages total scanned 10060649.40 ( +0.00%) 8640624.33 ( -14.11%)
Pages total reclaimed 1984391.27 ( +0.00%) 1340415.53 ( -32.45%)
Swap out 884585.73 ( +0.00%) 417781.93 ( -52.77%)
Swap in 287106.27 ( +0.00%) 95589.73 ( -66.71%)
File refaults 551697.60 ( +0.00%) 426474.80 ( -22.70%)
Link: https://lkml.kernel.org/r/20250416135142.778933-3-hannes@cmpxchg.org
Fixes: a211c6550efc ("mm: page_alloc: defrag_mode kswapd/kcompactd watermarks")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Brendan Jackman <jackmanb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Vlastimil points out that commit a211c6550efc ("mm: page_alloc:
defrag_mode kswapd/kcompactd watermarks") switched kswapd from
zone_watermark_ok_safe() to the standard, percpu-cached version of reading
free pages, thus dropping the watermark safety precautions for systems
with high CPU counts (e.g. >212 cpus on 64G). Restore them.
Since zone_watermark_ok_safe() is no longer the right interface, and this
was the last caller of the function anyway, open-code the
zone_page_state_snapshot() conditional and delete the function.
Link: https://lkml.kernel.org/r/20250416135142.778933-2-hannes@cmpxchg.org
Fixes: a211c6550efc ("mm: page_alloc: defrag_mode kswapd/kcompactd watermarks")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Brendan Jackman <jackmanb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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stabilization
In __folio_remove_rmap() for RMAP_LEVEL_PMD/RMAP_LEVEL_PUD and with
CONFIG_PAGE_MAPCOUNT we first decrement the folio mapcount (and recompute
mapped shared vs. mapped exclusively) to then adjust the entire mapcount.
This means that another process might stumble in do_wp_page() over a
PTE-mapped PMD folio that is indicated as "exclusively mapped", but still
has an entire mapcount (PMD mapping), because it is racing with the
process that is unmapping the folio (PMD mapping). Note that do_wp_page()
will back off once it detects the remaining folio reference from the
process that is in the process of unmapping the folio.
This will trigger the early VM_WARN_ON_ONCE(folio_entire_mapcount(folio))
check in do_wp_page(), that can easily be reproduced by looping a couple
of times over allocating a PMD THP, forking a child where we immediately
unmap it again, and writing in the parent concurrently to the THP.
[ 252.738129][T16470] ------------[ cut here ]------------
[ 252.739267][T16470] WARNING: CPU: 3 PID: 16470 at mm/memory.c:3738 do_wp_page+0x2a75/0x2c00
[ 252.740968][T16470] Modules linked in:
[ 252.741958][T16470] CPU: 3 UID: 0 PID: 16470 Comm: ...
...
[ 252.765841][T16470] <TASK>
[ 252.766419][T16470] ? srso_alias_return_thunk+0x5/0xfbef5
[ 252.767558][T16470] ? rcu_is_watching+0x12/0x60
[ 252.768525][T16470] ? srso_alias_return_thunk+0x5/0xfbef5
[ 252.769645][T16470] ? srso_alias_return_thunk+0x5/0xfbef5
[ 252.770778][T16470] ? lock_acquire+0x33/0x80
[ 252.771697][T16470] ? __handle_mm_fault+0x5e8/0x3e40
[ 252.772735][T16470] ? __handle_mm_fault+0x5e8/0x3e40
[ 252.773781][T16470] __handle_mm_fault+0x1869/0x3e40
[ 252.774839][T16470] handle_mm_fault+0x22a/0x640
[ 252.775808][T16470] do_user_addr_fault+0x618/0x1000
[ 252.776847][T16470] exc_page_fault+0x68/0xd0
[ 252.777775][T16470] asm_exc_page_fault+0x26/0x30
While we could adjust the sequence in __folio_remove_rmap(), let's rater
move the mapcount sanity checks after the mapcount vs. refcount
stabilization phase. With this fix, a simple reproducer is happy.
While at it, convert the two VM_WARN_ON_ONCE() we are moving to
VM_WARN_ON_ONCE_FOLIO().
Link: https://lkml.kernel.org/r/20250415095007.569836-1-david@redhat.com
Fixes: 1da190f4d0a6 ("mm: Copy-on-Write (COW) reuse support for PTE-mapped THP")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: syzbot+5e8feb543ca8e12e0ede@syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/67fab4fe.050a0220.2c5fcf.0011.GAE@google.com
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
commit 4eeec8c89a0c ("mm: move hugetlb specific things in folio to
page[3]") shifted hugetlb specific stuff, and now mapping overlaps
_hugetlb_cgroup field.
Upon restoring the vmemmap for HVO, only the first two tail pages are
reset, and this causes the check in free_tail_page_prepare() to fail as it
finds an unexpected mapping value in some tails.
Increment the number of pages to be reset to 4 (head + 3 tail pages)
Link: https://lkml.kernel.org/r/20250415111859.376302-1-osalvador@suse.de
Fixes: 4eeec8c89a0c ("mm: move hugetlb specific things in folio to page[3]")
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Suggested-by: David Hildenbrand <david@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Not like fault_in_readable() or fault_in_writeable(), in
fault_in_safe_writeable() local variable 'start' is increased page by page
to loop till the whole address range is handled. However, it mistakenly
calculates the size of the handled range with 'uaddr - start'.
Fix it here.
Andreas said:
: In gfs2, fault_in_iov_iter_writeable() is used in
: gfs2_file_direct_read() and gfs2_file_read_iter(), so this potentially
: affects buffered as well as direct reads. This bug could cause those
: gfs2 functions to spin in a loop.
Link: https://lkml.kernel.org/r/20250410035717.473207-1-bhe@redhat.com
Link: https://lkml.kernel.org/r/20250410035717.473207-2-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Fixes: fe673d3f5bf1 ("mm: gup: make fault_in_safe_writeable() use fixup_user_fault()")
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Yanjun.Zhu <yanjun.zhu@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
commit 73f839b6d2ed addressed an issue regarding the swap counter leak
that occurred from an offline cgroup. However, commit 89ce924f0bd4
modified the parameter from @swap_memcg to @memcg (presumably this
alteration was introduced while resolving conflicts). Fix this problem by
reverting this minor change.
Link: https://lkml.kernel.org/r/20250410081812.10073-1-songmuchun@bytedance.com
Fixes: 89ce924f0bd4 ("mm: memcontrol: move memsw charge callbacks to v1")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
When the last page in the zone is accepted, __accept_page() calls
static_branch_dec(). This function takes cpu_hotplug_lock, which can lead
to a deadlock if the allocation occurs during CPU bringup path as
_cpu_up() also takes the lock.
To prevent this deadlock, defer static_branch_dec() to a workqueue.
Call static_branch_dec() only when the workqueue is not yet initialized.
Workqueues are initialized before CPU bring up, so this will not conflict
with the first scenario.
Link: https://lkml.kernel.org/r/20250329171030.3942298-1-kirill.shutemov@linux.intel.com
Fixes: 55ad43e8ba0f ("mm: add a helper to accept page")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Srikanth Aithal <sraithal@amd.com>
Tested-by: Srikanth Aithal <sraithal@amd.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Ashish Kalra <ashish.kalra@amd.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: "Mike Rapoport (IBM)" <rppt@kernel.org>
Cc: Thomas Lendacky <thomas.lendacky@amd.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Cross-merge networking fixes after downstream PR (net-6.15-rc3).
No conflicts. Adjacent changes:
tools/net/ynl/pyynl/ynl_gen_c.py
4d07bbf2d456 ("tools: ynl-gen: don't declare loop iterator in place")
7e8ba0c7de2b ("tools: ynl: don't use genlmsghdr in classic netlink")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab
Pull slab fix from Vlastimil Babka:
- Stable fix adding zero initialization of slab->obj_ext to prevent
crashes with allocation profiling (Suren Baghdasaryan)
* tag 'slab-for-6.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
slab: ensure slab->obj_exts is clear in a newly allocated slab page
|
|
When we invoke strscpy() with a maximum size of N bytes, it assumes
that:
- It can always read N bytes from the source.
- It always write N bytes (zero-padded) to the destination.
On aarch64 with Memory Tagging Extension enabled if we pass an N that is
bigger then the source buffer, it would previously trigger an MTE fault.
Implement a KASAN KUnit test that triggers the issue with the previous
implementation of read_word_at_a_time() on aarch64 with MTE enabled.
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Co-developed-by: Peter Collingbourne <pcc@google.com>
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://linux-review.googlesource.com/id/If88e396b9e7c058c1a4b5a252274120e77b1898a
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20250403000703.2584581-3-pcc@google.com
Signed-off-by: Kees Cook <kees@kernel.org>
|
|
Currently in shrink_folio_list(), reclaim for folios under writeback
falls into 3 different cases:
1) Reclaim is encountering an excessive number of folios under
writeback and this folio has both the writeback and reclaim flags
set
2) Dirty throttling is enabled (this happens if reclaim through cgroup
is not enabled, if reclaim through cgroupv2 memcg is enabled, or
if reclaim is on the root cgroup), or if the folio is not marked for
immediate reclaim, or if the caller does not have __GFP_FS (or
__GFP_IO if it's going to swap) set
3) Legacy cgroupv1 encounters a folio that already has the reclaim flag
set and the caller did not have __GFP_FS (or __GFP_IO if swap) set
In cases 1) and 2), we activate the folio and skip reclaiming it while
in case 3), we wait for writeback to finish on the folio and then try
to reclaim the folio again. In case 3, we wait on writeback because
cgroupv1 does not have dirty folio throttling, as such this is a
mitigation against the case where there are too many folios in writeback
with nothing else to reclaim.
If a filesystem (eg fuse) may deadlock due to reclaim waiting on
writeback, then the filesystem needs to add inefficient messy workarounds
to prevent this. To improve the performance of these filesystems, this
commit adds two things:
a) a AS_WRITEBACK_MAY_DEADLOCK_ON_RECLAIM mapping flag that filesystems
may set to indicate that reclaim should not wait on writeback
b) if legacy memcg encounters a folio with this
AS_WRITEBACK_MAY_DEADLOCK_ON_RECLAIM flag set (eg case 3), the folio
will be activated and skip reclaim (eg default to behavior in case 2)
instead.
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
|
|
Since we are about to stash some more information into the pp_magic
field, let's move the magic signature checks into a pair of helper
functions so it can be changed in one place.
Reviewed-by: Mina Almasry <almasrymina@google.com>
Tested-by: Yonglong Liu <liuyonglong@huawei.com>
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20250409-page-pool-track-dma-v9-1-6a9ef2e0cba8@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
ktest recently reported crashes while running several buffered io tests
with __alloc_tagging_slab_alloc_hook() at the top of the crash call stack.
The signature indicates an invalid address dereference with low bits of
slab->obj_exts being set. The bits were outside of the range used by
page_memcg_data_flags and objext_flags and hence were not masked out
by slab_obj_exts() when obtaining the pointer stored in slab->obj_exts.
The typical crash log looks like this:
00510 Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010
00510 Mem abort info:
00510 ESR = 0x0000000096000045
00510 EC = 0x25: DABT (current EL), IL = 32 bits
00510 SET = 0, FnV = 0
00510 EA = 0, S1PTW = 0
00510 FSC = 0x05: level 1 translation fault
00510 Data abort info:
00510 ISV = 0, ISS = 0x00000045, ISS2 = 0x00000000
00510 CM = 0, WnR = 1, TnD = 0, TagAccess = 0
00510 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
00510 user pgtable: 4k pages, 39-bit VAs, pgdp=0000000104175000
00510 [0000000000000010] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000
00510 Internal error: Oops: 0000000096000045 [#1] SMP
00510 Modules linked in:
00510 CPU: 10 UID: 0 PID: 7692 Comm: cat Not tainted 6.15.0-rc1-ktest-g189e17946605 #19327 NONE
00510 Hardware name: linux,dummy-virt (DT)
00510 pstate: 20001005 (nzCv daif -PAN -UAO -TCO -DIT +SSBS BTYPE=--)
00510 pc : __alloc_tagging_slab_alloc_hook+0xe0/0x190
00510 lr : __kmalloc_noprof+0x150/0x310
00510 sp : ffffff80c87df6c0
00510 x29: ffffff80c87df6c0 x28: 000000000013d1ff x27: 000000000013d200
00510 x26: ffffff80c87df9e0 x25: 0000000000000000 x24: 0000000000000001
00510 x23: ffffffc08041953c x22: 000000000000004c x21: ffffff80c0002180
00510 x20: fffffffec3120840 x19: ffffff80c4821000 x18: 0000000000000000
00510 x17: fffffffec3d02f00 x16: fffffffec3d02e00 x15: fffffffec3d00700
00510 x14: fffffffec3d00600 x13: 0000000000000200 x12: 0000000000000006
00510 x11: ffffffc080bb86c0 x10: 0000000000000000 x9 : ffffffc080201e58
00510 x8 : ffffff80c4821060 x7 : 0000000000000000 x6 : 0000000055555556
00510 x5 : 0000000000000001 x4 : 0000000000000010 x3 : 0000000000000060
00510 x2 : 0000000000000000 x1 : ffffffc080f50cf8 x0 : ffffff80d801d000
00510 Call trace:
00510 __alloc_tagging_slab_alloc_hook+0xe0/0x190 (P)
00510 __kmalloc_noprof+0x150/0x310
00510 __bch2_folio_create+0x5c/0xf8
00510 bch2_folio_create+0x2c/0x40
00510 bch2_readahead+0xc0/0x460
00510 read_pages+0x7c/0x230
00510 page_cache_ra_order+0x244/0x3a8
00510 page_cache_async_ra+0x124/0x170
00510 filemap_readahead.isra.0+0x58/0xa0
00510 filemap_get_pages+0x454/0x7b0
00510 filemap_read+0xdc/0x418
00510 bch2_read_iter+0x100/0x1b0
00510 vfs_read+0x214/0x300
00510 ksys_read+0x6c/0x108
00510 __arm64_sys_read+0x20/0x30
00510 invoke_syscall.constprop.0+0x54/0xe8
00510 do_el0_svc+0x44/0xc8
00510 el0_svc+0x18/0x58
00510 el0t_64_sync_handler+0x104/0x130
00510 el0t_64_sync+0x154/0x158
00510 Code: d5384100 f9401c01 b9401aa3 b40002e1 (f8227881)
00510 ---[ end trace 0000000000000000 ]---
00510 Kernel panic - not syncing: Oops: Fatal exception
00510 SMP: stopping secondary CPUs
00510 Kernel Offset: disabled
00510 CPU features: 0x0000,000000e0,00000410,8240500b
00510 Memory Limit: none
Investigation indicates that these bits are already set when we allocate
slab page and are not zeroed out after allocation. We are not yet sure
why these crashes start happening only recently but regardless of the
reason, not initializing a field that gets used later is wrong. Fix it
by initializing slab->obj_exts during slab page allocation.
Fixes: 21c690a349ba ("mm: introduce slabobj_ext to support slab object extensions")
Reported-by: Kent Overstreet <kent.overstreet@linux.dev>
Tested-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Kent Overstreet <kent.overstreet@linux.dev>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20250411155737.1360746-1-surenb@google.com
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
|
|
In the case of apply_to_existing_page_range(), apply_to_pte_range() is
reached with 'create' set to false. When !create, the loop over the PTE
page table is broken.
apply_to_pte_range() will only move to the next PTE entry if 'create' is
true or if the current entry is not pte_none().
This means that the user of apply_to_existing_page_range() will not have
'fn' called for any entries after the first pte_none() in the PTE page
table.
Fix the loop logic in apply_to_pte_range().
There are no known runtime issues from this, but the fix is trivial enough
for stable@ even without a known buggy user.
Link: https://lkml.kernel.org/r/20250409094043.1629234-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Fixes: be1db4753ee6 ("mm/memory.c: add apply_to_existing_page_range() helper")
Cc: Daniel Axtens <dja@axtens.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
We got a late smatch warning and some additional review feedback.
smatch warnings:
mm/memory.c:1428 copy_page_range() error: uninitialized symbol 'pfn'.
We actually use the pfn only when it is properly initialized; however, we
may pass an uninitialized value to a function -- although it will not use
it that likely still is UB in C.
So let's just fix it by always initializing pfn in the caller of
track_pfn_copy(), and improving the documentation of track_pfn_copy().
While at it, clarify the doc of untrack_pfn_copy(), that internal checks
make sure if we actually have to untrack anything.
Link: https://lkml.kernel.org/r/20250408085950.976103-1-david@redhat.com
Fixes: dc84bc2aba85 ("x86/mm/pat: Fix VM_PAT handling when fork() fails in copy_page_range()")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Closes: https://lore.kernel.org/r/202503270941.IFILyNCX-lkp@intel.com/
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Rik van Riel <riel@surriel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
filemap_get_folios_contig() is supposed to return distinct folios found
within [start, end]. Large folios in the Xarray become multi-index
entries. xas_next() can iterate through the sub-indexes before finding a
sibling entry and breaking out of the loop.
This can result in a returned folio_batch containing an indeterminate
number of duplicate folios, which forces the callers to skeptically handle
the returned batch. This is inefficient and incurs a large maintenance
overhead.
We can fix this by calling xas_advance() after we have successfully adding
a folio to the batch to ensure our Xarray is positioned such that it will
correctly find the next folio - similar to filemap_get_read_batch().
Link: https://lkml.kernel.org/r/Z-8s1-kiIDkzgRbc@fedora
Fixes: 35b471467f88 ("filemap: add filemap_get_folios_contig()")
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reported-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
Closes: https://lkml.kernel.org/r/b714e4de-2583-4035-b829-72cfb5eb6fc6@gmx.com
Tested-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vivek Kasireddy <vivek.kasireddy@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Missing line break at the end of the format string.
Link: https://lkml.kernel.org/r/20250407103017.2979821-1-18810879172@163.com
Signed-off-by: wangxuewen <wangxuewen@kylinos.cn>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
In set_max_huge_pages(), min_count is computed taking into account surplus
huge pages, which might lead in some cases to not be able to free huge
pages and end up accounting them as surplus instead.
One way to solve it is to subtract surplus_huge_pages directly, but we
cannot do it blindly because there might be surplus pages that are also
free pages, which might happen when we fail to restore the vmemmap for
optimized hvo pages. So we could be subtracting the same page twice.
In order to work this around, let us first compute the number of free
persistent pages, and use that along with surplus pages to compute
min_count.
Steps to reproduce:
1) create 5 hugetlb folios in Node0
2) run a program to use all the hugetlb folios
3) echo 0 > nr_hugepages for Node0 to free the hugetlb folios. Thus
the 5 hugetlb folios in Node0 are accounted as surplus.
4) create 5 hugetlb folios in Node1
5) echo 0 > nr_hugepages for Node1 to free the hugetlb folios
The result:
Node0 Node1
Total 5 5
Free 0 5
Surp 5 5
The result with this patch:
Node0 Node1
Total 5 0
Free 0 0
Surp 5 0
Link: https://lkml.kernel.org/r/20250409055957.3774471-1-tujinjiang@huawei.com
Link: https://lkml.kernel.org/r/20250407124706.2688092-1-tujinjiang@huawei.com
Fixes: 9a30523066cd ("hugetlb: add per node hstate attributes")
Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com>
Acked-by: Oscar Salvador <osalvador@suse.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The cma_declare_contiguous_nid code was refactored by commit c009da4258f9
("mm, cma: support multiple contiguous ranges, if requested"), so that it
could use an internal function to attempt a single range area first, and
then try a multi-range one.
However, that meant that the actual base address used for the !fixed case
(base == 0) wasn't available one level up to be printed in the
informational message, and it would always end up printing a base address
of 0 in the boot message.
Make the internal function take a phys_addr_t pointer to the base address,
so that the value is available to the caller.
[fvdl@google.com: v2]
Link: https://lkml.kernel.org/r/20250408164000.3215690-1-fvdl@google.com
Link: https://lkml.kernel.org/r/20250407165435.2567898-1-fvdl@google.com
Fixes: c009da4258f9 ("mm, cma: support multiple contiguous ranges, if requested")
Signed-off-by: Frank van der Linden <fvdl@google.com>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Closes: https://lore.kernel.org/linux-mm/CAMuHMdVWviQ7O9yBFE3f=ev0eVb1CnsQvR6SKtEROBbM6z7g3w@mail.gmail.com/
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The test robot identified c2f6ea38fc1b ("mm: page_alloc: don't steal
single pages from biggest buddy") as the root cause of a 56.4% regression
in vm-scalability::lru-file-mmap-read.
Carlos reports an earlier patch, c0cd6f557b90 ("mm: page_alloc: fix
freelist movement during block conversion"), as the root cause for a
regression in worst-case zone->lock+irqoff hold times.
Both of these patches modify the page allocator's fallback path to be less
greedy in an effort to stave off fragmentation. The flip side of this is
that fallbacks are also less productive each time around, which means the
fallback search can run much more frequently.
Carlos' traces point to rmqueue_bulk() specifically, which tries to refill
the percpu cache by allocating a large batch of pages in a loop. It
highlights how once the native freelists are exhausted, the fallback code
first scans orders top-down for whole blocks to claim, then falls back to
a bottom-up search for the smallest buddy to steal. For the next batch
page, it goes through the same thing again.
This can be made more efficient. Since rmqueue_bulk() holds the
zone->lock over the entire batch, the freelists are not subject to outside
changes; when the search for a block to claim has already failed, there is
no point in trying again for the next page.
Modify __rmqueue() to remember the last successful fallback mode, and
restart directly from there on the next rmqueue_bulk() iteration.
Oliver confirms that this improves beyond the regression that the test
robot reported against c2f6ea38fc1b:
commit:
f3b92176f4 ("tools/selftests: add guard region test for /proc/$pid/pagemap")
c2f6ea38fc ("mm: page_alloc: don't steal single pages from biggest buddy")
acc4d5ff0b ("Merge tag 'net-6.15-rc0' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net")
2c847f27c3 ("mm: page_alloc: speed up fallbacks in rmqueue_bulk()") <--- your patch
f3b92176f4f7100f c2f6ea38fc1b640aa7a2e155cc1 acc4d5ff0b61eb1715c498b6536 2c847f27c37da65a93d23c237c5
---------------- --------------------------- --------------------------- ---------------------------
%stddev %change %stddev %change %stddev %change %stddev
\ | \ | \ | \
25525364 ± 3% -56.4% 11135467 -57.8% 10779336 +31.6% 33581409 vm-scalability.throughput
Carlos confirms that worst-case times are almost fully recovered
compared to before the earlier culprit patch:
2dd482ba627d (before freelist hygiene): 1ms
c0cd6f557b90 (after freelist hygiene): 90ms
next-20250319 (steal smallest buddy): 280ms
this patch : 8ms
[jackmanb@google.com: comment updates]
Link: https://lkml.kernel.org/r/D92AC0P9594X.3BML64MUKTF8Z@google.com
[hannes@cmpxchg.org: reset rmqueue_mode in rmqueue_buddy() error loop, per Yunsheng Lin]
Link: https://lkml.kernel.org/r/20250409140023.GA2313@cmpxchg.org
Link: https://lkml.kernel.org/r/20250407180154.63348-1-hannes@cmpxchg.org
Fixes: c0cd6f557b90 ("mm: page_alloc: fix freelist movement during block conversion")
Fixes: c2f6ea38fc1b ("mm: page_alloc: don't steal single pages from biggest buddy")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Brendan Jackman <jackmanb@google.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Reported-by: Carlos Song <carlos.song@nxp.com>
Tested-by: Carlos Song <carlos.song@nxp.com>
Tested-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202503271547.fc08b188-lkp@intel.com
Reviewed-by: Brendan Jackman <jackmanb@google.com>
Tested-by: Shivank Garg <shivankg@amd.com>
Acked-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org> [6.10+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Modules without a description now cause a warning:
WARNING: modpost: missing MODULE_DESCRIPTION() in mm/kasan/kasan_test.o
[akpm@linux-foundation.org: update description text, per Andrey]
Link: https://lkml.kernel.org/r/20250324173242.1501003-9-arnd@kernel.org
Fixes: 6c6c1fc09de3 ("modpost: require a MODULE_DESCRIPTION()")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jeff Johnson <jeff.johnson@oss.qualcomm.com>
Cc: Macro Elver <elver@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nihar Chaithanya <niharchaithanya@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sabyrzhan Tasbolatov <snovitoll@gmail.com>
Cc: Stehen Rothwell <sfr@canb.auug.org.au>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Currently, if a VMA merge fails due to an OOM condition arising on commit
merge or a failure to duplicate anon_vma's, we report this so the caller
can handle it.
However there are cases where the caller is only ostensibly trying a
merge, and doesn't mind if it fails due to this condition.
Since we do not want to introduce an implicit assumption that we only
actually modify VMAs after OOM conditions might arise, add a 'give up on
oom' option and make an explicit contract that, should this flag be set, we
absolutely will not modify any VMAs should OOM arise and just bail out.
Since it'd be very unusual for a user to try to vma_modify() with this flag
set but be specifying a range within a VMA which ends up being split (which
can fail due to rlimit issues, not only OOM), we add a debug warning for
this condition.
The motivating reason for this is uffd release - syzkaller (and Pedro
Falcato's VERY astute analysis) found a way in which an injected fault on
allocation, triggering an OOM condition on commit merge, would result in
uffd code becoming confused and treating an error value as if it were a VMA
pointer.
To avoid this, we make use of this new VMG flag to ensure that this never
occurs, utilising the fact that, should we be clearing entire VMAs, we do
not wish an OOM event to be reported to us.
Many thanks to Pedro Falcato for his excellent analysis and Jann Horn for
his insightful and intelligent analysis of the situation, both of whom were
instrumental in this fix.
Link: https://lkml.kernel.org/r/20250321100937.46634-1-lorenzo.stoakes@oracle.com
Reported-by: syzbot+20ed41006cf9d842c2b5@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/67dc67f0.050a0220.25ae54.001e.GAE@google.com/
Fixes: 47b16d0462a4 ("mm: abort vma_modify() on merge out of memory failure")
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Suggested-by: Pedro Falcato <pfalcato@suse.de>
Suggested-by: Jann Horn <jannh@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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It's wrong to use nid directly since the nid may be changed in allocation.
Use folio_nid() to obtain the nid of folio instead.
Fix: 2273dea6b1e1 ("mm/hugetlb: update nr_huge_pages and surplus_huge_pages together")
Link: https://lkml.kernel.org/r/20250403064138.2867929-1-liushixin2@huawei.com
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Acked-by: Oscar Salvador <osalvador@suse.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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spin_trylock followed by spin_lock will cause extra write cache access.
If the lock is contended it may cause unnecessary cache line bouncing and
will execute redundant irq restore/save pair. Therefore, check
alloc/fpi_flags first and use spin_trylock or spin_lock.
Link: https://lkml.kernel.org/r/20250331002809.94758-1-alexei.starovoitov@gmail.com
Fixes: 97769a53f117 ("mm, bpf: Introduce try_alloc_pages() for opportunistic page allocation")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Daniel Borkman <daniel@iogearbox.net>
Cc: Martin KaFai Lau <martin.lau@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The compaction code doesn't take references on pages until we're certain
we should attempt to handle it.
In the hugetlb case, isolate_or_dissolve_huge_page() may return -EBUSY
without taking a reference to the folio associated with our pfn. If our
folio's refcount drops to 0, compound_nr() becomes unpredictable, making
low_pfn and nr_scanned unreliable. The user-visible effect is minimal -
this should rarely happen (if ever).
Fix this by storing the folio statistics earlier on the stack (just like
the THP and Buddy cases).
Also revert commit 66fe1cf7f581 ("mm: compaction: use helper compound_nr
in isolate_migratepages_block") to make backporting easier.
Link: https://lkml.kernel.org/r/20250401021025.637333-1-vishal.moola@gmail.com
Fixes: 369fa227c219 ("mm: make alloc_contig_range handle free hugetlb pages")
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Acked-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Partially revert commit 0aaddfb06882 ("locking/local_lock: Introduce
localtry_lock_t"). Remove localtry_*() helpers, since localtry_lock()
name might be misinterpreted as "try lock".
Introduce local_trylock[_irqsave]() helpers that only work with newly
introduced local_trylock_t type. Note that attempt to use
local_trylock[_irqsave]() with local_lock_t will cause compilation
failure.
Usage and behavior in !PREEMPT_RT:
local_lock_t lock; // sizeof(lock) == 0
local_lock(&lock); // preempt disable
local_lock_irqsave(&lock, ...); // irq save
if (local_trylock_irqsave(&lock, ...)) // compilation error
local_trylock_t lock; // sizeof(lock) == 4
local_lock(&lock); // preempt disable, acquired = 1
local_lock_irqsave(&lock, ...); // irq save, acquired = 1
if (local_trylock(&lock)) // if (!acquired) preempt disable, acquired = 1
if (local_trylock_irqsave(&lock, ...)) // if (!acquired) irq save, acquired = 1
The existing local_lock_*() macros can be used either with local_lock_t or
local_trylock_t. With local_trylock_t they set acquired = 1 while
local_unlock_*() clears it.
In !PREEMPT_RT local_lock_irqsave(local_lock_t *) disables interrupts to
protect critical section, but it doesn't prevent NMI, so the fully
reentrant code cannot use local_lock_irqsave(local_lock_t *) for exclusive
access.
The local_lock_irqsave(local_trylock_t *) helper disables interrupts and
sets acquired=1, so local_trylock_irqsave(local_trylock_t *) from NMI
attempting to acquire the same lock will return false.
In PREEMPT_RT local_lock_irqsave() maps to preemptible spin_lock(). Map
local_trylock_irqsave() to preemptible spin_trylock(). When in hard IRQ
or NMI return false right away, since spin_trylock() is not safe due to
explicit locking in the underneath rt_spin_trylock() implementation.
Removing this explicit locking and attempting only "trylock" is undesired
due to PI implications.
The local_trylock() without _irqsave can be used to avoid the cost of
disabling/enabling interrupts by only disabling preemption, so
local_trylock() in an interrupt attempting to acquire the same lock will
return false.
Note there is no need to use local_inc for acquired variable, since it's a
percpu variable with strict nesting scopes.
Note that guard(local_lock)(&lock) works only for "local_lock_t lock".
The patch also makes sure that local_lock_release(l) is called before
WRITE_ONCE(l->acquired, 0). Though IRQs are disabled at this point the
local_trylock() from NMI will succeed and local_lock_acquire(l) will warn.
Link: https://lkml.kernel.org/r/20250403025514.41186-1-alexei.starovoitov@gmail.com
Fixes: 0aaddfb06882 ("locking/local_lock: Introduce localtry_lock_t")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Daniel Borkman <daniel@iogearbox.net>
Cc: Linus Torvalds <torvalds@linuxfoundation.org>
Cc: Martin KaFai Lau <martin.lau@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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All callers and implementations are now removed, so remove the operation
and update the documentation to match.
Signed-off-by: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Link: https://lore.kernel.org/r/20250402150005.2309458-10-willy@infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Call swap_writeout() and shmem_writeout() from pageout() instead.
Signed-off-by: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Link: https://lore.kernel.org/r/20250402150005.2309458-9-willy@infradead.org
Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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This will be the replacement for shmem_writepage().
Signed-off-by: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Link: https://lore.kernel.org/r/20250402150005.2309458-6-willy@infradead.org
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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The ->writepage operation has been removed from all filesystems but
shmem and swap, neither of which call in here. Remove this alternative
to calling ->writepages.
Signed-off-by: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Link: https://lore.kernel.org/r/20250402150005.2309458-5-willy@infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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The writepage callback is going away; filesystems must implement
migrate_folio or else dirty folios will not be migratable.
Signed-off-by: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Link: https://lore.kernel.org/r/20250402150005.2309458-4-willy@infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Commit 61167ad5fecd ("mm: pass nid to reserve_bootmem_region()") introduce
a way to set nid to all reserved region.
But there is a corner case it will leave some region with invalid nid.
When memblock_set_node() doubles the array of memblock.reserved, it may
lead to a new reserved region before current position. The new region
will be left with an invalid node id.
Repeat the process when detecting it.
Fixes: 61167ad5fecd ("mm: pass nid to reserve_bootmem_region()")
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
CC: Mike Rapoport <rppt@kernel.org>
CC: Yajun Deng <yajun.deng@linux.dev>
CC: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250318071948.23854-3-richard.weiyang@gmail.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
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