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There is a lot of provision for flexibility that isn't actually needed or
used. Zswap (the only zpool user) always passes zpool_ops with an .evict
method set. The backends who reclaim only do so for zswap, so they can
also directly call zpool_ops without indirection or checks.
Finally, there is no need to check the retries parameters and bail with
-EINVAL in the reclaim function, when that's called just a few lines below
with a hard-coded 8. There is no need to duplicate the evictable and
sleep_mapped attrs from the driver in zpool_ops.
Link: https://lkml.kernel.org/r/20221128191616.1261026-3-nphamcs@gmail.com
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Nhat Pham <nphamcs@gmail.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "Implement writeback for zsmalloc", v7.
Unlike other zswap allocators such as zbud or z3fold, zsmalloc currently
lacks the writeback mechanism. This means that when the zswap pool is
full, it will simply reject further allocations, and the pages will be
written directly to swap.
This series of patches implements writeback for zsmalloc. When the zswap
pool becomes full, zsmalloc will attempt to evict all the compressed
objects in the least-recently used zspages.
This patch (of 6):
zswap's customary lock order is tree->lock before pool->lock, because the
tree->lock protects the entries' refcount, and the free callbacks in the
backends acquire their respective pool locks to dispatch the backing
object. zsmalloc's map callback takes the pool lock, so zswap must not
grab the tree->lock while a handle is mapped. This currently only happens
during writeback, which isn't implemented for zsmalloc. In preparation
for it, move the tree->lock section out of the mapped entry section
Link: https://lkml.kernel.org/r/20221128191616.1261026-1-nphamcs@gmail.com
Link: https://lkml.kernel.org/r/20221128191616.1261026-2-nphamcs@gmail.com
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Nhat Pham <nphamcs@gmail.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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When MADV_PAGEOUT is called on a private file mapping VMA region, we bail
out early if the process is neither owner nor write capable of the file.
However, this VMA may have both private/shared clean pages and private
dirty pages. The opportunity of paging out the private dirty pages (Anon
pages) is missed. Fix this behavior by allowing private file mappings
pageout further and perform the file access check along with PageAnon()
during page walk.
We observe ~10% improvement in zram usage, thus leaving more available
memory on a 4GB RAM system running Android.
[quic_pkondeti@quicinc.com: v2]
Link: https://lkml.kernel.org/r/1669962597-27724-1-git-send-email-quic_pkondeti@quicinc.com
Link: https://lkml.kernel.org/r/1667971116-12900-1-git-send-email-quic_pkondeti@quicinc.com
Signed-off-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
Cc: Charan Teja Kalla <quic_charante@quicinc.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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"mm_khugepaged_collapse_file" for capturing is_shmem.
Currently, is_shmem is not being captured. Capturing is_shmem is useful
as it can indicate if tmpfs is being used as a backing store instead of
persistent storage. Add the tracepoint in collapse_file() named
"mm_khugepaged_collapse_file" for capturing is_shmem.
[gautammenghani201@gmail.com: swap is_shmem and addr to save space, per Steven Rostedt]
Link: https://lkml.kernel.org/r/20221202201807.182829-1-gautammenghani201@gmail.com
Link: https://lkml.kernel.org/r/20221026052218.148234-1-gautammenghani201@gmail.com
Signed-off-by: Gautam Menghani <gautammenghani201@gmail.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> [tracing]
Cc: David Hildenbrand <david@redhat.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Fortunately, the last user (KSM) is gone, so let's just remove this rather
special code from generic GUP handling -- especially because KSM never
required the PMD handling as KSM only deals with individual base pages.
[akpm@linux-foundation.org: fix merge snafu]Link: https://lkml.kernel.org/r/20221021101141.84170-10-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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FOLL_MIGRATION exists only for the purpose of break_ksm(), and actually,
there is not even the need to wait for the migration to finish, we only
want to know if we're dealing with a KSM page.
Using follow_page() just to identify a KSM page overcomplicates GUP code.
Let's use walk_page_range_vma() instead, because we don't actually care
about the page itself, we only need to know a single property -- no need
to even grab a reference.
So, get rid of follow_page() usage such that we can get rid of
FOLL_MIGRATION now and eventually be able to get rid of follow_page() in
the future.
In my setup (AMD Ryzen 9 3900X), running the KSM selftest to test unmerge
performance on 2 GiB (taskset 0x8 ./ksm_tests -D -s 2048), this results in
a performance degradation of ~2% (old: ~5010 MiB/s, new: ~4900 MiB/s). I
don't think we particularly care for now.
Interestingly, the benchmark reduction is due to the single callback.
Adding a second callback (e.g., pud_entry()) reduces the benchmark by
another 100-200 MiB/s.
Link: https://lkml.kernel.org/r/20221021101141.84170-9-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Let's add walk_page_range_vma(), which is similar to walk_page_vma(),
however, is only interested in a subset of the VMA range.
To be used in KSM code to stop using follow_page() next.
Link: https://lkml.kernel.org/r/20221021101141.84170-8-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Let's stop breaking COW via a fake write fault and let's use
FAULT_FLAG_UNSHARE instead. This avoids any wrong side effects of the
fake write fault, such as mapping the PTE writable and marking the pte
dirty/softdirty.
Consequently, we will no longer trigger a fake write fault and break COW
without any such side-effects.
Also, this fixes KSM interaction with userfaultfd-wp: when we have a KSM
page that's write-protected by userfaultfd, break_ksm()->handle_mm_fault()
will fail with VM_FAULT_SIGBUS and will simply return in break_ksm() with
0 instead of actually breaking COW.
For now, the KSM unmerge tests can trigger that:
$ sudo ./ksm_functional_tests
TAP version 13
1..3
# [RUN] test_unmerge
ok 1 Pages were unmerged
# [RUN] test_unmerge_discarded
ok 2 Pages were unmerged
# [RUN] test_unmerge_uffd_wp
not ok 3 Pages were unmerged
Bail out! 1 out of 3 tests failed
# Planned tests != run tests (2 != 3)
# Totals: pass:2 fail:1 xfail:0 xpass:0 skip:0 error:0
The warning in dmesg also indicates this wrong handling:
[ 230.096368] FAULT_FLAG_ALLOW_RETRY missing 881
[ 230.100822] CPU: 1 PID: 1643 Comm: ksm-uffd-wp [...]
[ 230.110124] Hardware name: [...]
[ 230.117775] Call Trace:
[ 230.120227] <TASK>
[ 230.122334] dump_stack_lvl+0x44/0x5c
[ 230.126010] handle_userfault.cold+0x14/0x19
[ 230.130281] ? tlb_finish_mmu+0x65/0x170
[ 230.134207] ? uffd_wp_range+0x65/0xa0
[ 230.137959] ? _raw_spin_unlock+0x15/0x30
[ 230.141972] ? do_wp_page+0x50/0x590
[ 230.145551] __handle_mm_fault+0x9f5/0xf50
[ 230.149652] ? mmput+0x1f/0x40
[ 230.152712] handle_mm_fault+0xb9/0x2a0
[ 230.156550] break_ksm+0x141/0x180
[ 230.159964] unmerge_ksm_pages+0x60/0x90
[ 230.163890] ksm_madvise+0x3c/0xb0
[ 230.167295] do_madvise.part.0+0x10c/0xeb0
[ 230.171396] ? do_syscall_64+0x67/0x80
[ 230.175157] __x64_sys_madvise+0x5a/0x70
[ 230.179082] do_syscall_64+0x58/0x80
[ 230.182661] ? do_syscall_64+0x67/0x80
[ 230.186413] entry_SYSCALL_64_after_hwframe+0x63/0xcd
This is primarily a fix for KSM+userfaultfd-wp, however, the fake write
fault was always questionable. As this fix is not easy to backport and
it's not very critical, let's not cc stable.
Link: https://lkml.kernel.org/r/20221021101141.84170-6-david@redhat.com
Fixes: 529b930b87d9 ("userfaultfd: wp: hook userfault handler to write protection fault")
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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All users -- GUP and KSM -- are gone, let's just remove it.
Link: https://lkml.kernel.org/r/20221021101141.84170-4-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Now that GUP no longer requires VM_FAULT_WRITE, break_ksm() is the sole
remaining user of VM_FAULT_WRITE. As we also want to stop triggering a
fake write fault and instead use FAULT_FLAG_UNSHARE -- similar to
GUP-triggered unsharing when taking a R/O pin on a shared anonymous page
(including KSM pages), let's stop relying on VM_FAULT_WRITE.
Let's rework break_ksm() to not rely on the return value of
handle_mm_fault() anymore to figure out whether COW-breaking was
successful. Simply perform another follow_page() lookup to verify the
result.
While this makes break_ksm() slightly less efficient, we can simplify
handle_mm_fault() a little and easily switch to FAULT_FLAG_UNSHARE without
introducing similar KSM-specific behavior for FAULT_FLAG_UNSHARE.
In my setup (AMD Ryzen 9 3900X), running the KSM selftest to test unmerge
performance on 2 GiB (taskset 0x8 ./ksm_tests -D -s 2048), this results in
a performance degradation of ~4% -- 5% (old: ~5250 MiB/s, new: ~5010
MiB/s).
I don't think that we particularly care about that performance drop when
unmerging. If it ever turns out to be an actual performance issue, we can
think about a better alternative for FAULT_FLAG_UNSHARE -- let's just keep
it simple for now.
Link: https://lkml.kernel.org/r/20221021101141.84170-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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As Peter points out, the caller passes a single VMA and can just do that
check itself.
And in fact, no existing users rely on test_walk() getting called. So
let's just remove it and make the implementation slightly more efficient.
Link: https://lkml.kernel.org/r/20221021101141.84170-7-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
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 misc fixes from Andrew Morton:
"Nine hotfixes.
Six for MM, three for other areas. Four of these patches address
post-6.0 issues"
* tag 'mm-hotfixes-stable-2022-12-10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
memcg: fix possible use-after-free in memcg_write_event_control()
MAINTAINERS: update Muchun Song's email
mm/gup: fix gup_pud_range() for dax
mmap: fix do_brk_flags() modifying obviously incorrect VMAs
mm/swap: fix SWP_PFN_BITS with CONFIG_PHYS_ADDR_T_64BIT on 32bit
tmpfs: fix data loss from failed fallocate
kselftests: cgroup: update kmem test precision tolerance
mm: do not BUG_ON missing brk mapping, because userspace can unmap it
mailmap: update Matti Vaittinen's email address
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memcg_write_event_control() accesses the dentry->d_name of the specified
control fd to route the write call. As a cgroup interface file can't be
renamed, it's safe to access d_name as long as the specified file is a
regular cgroup file. Also, as these cgroup interface files can't be
removed before the directory, it's safe to access the parent too.
Prior to 347c4a874710 ("memcg: remove cgroup_event->cft"), there was a
call to __file_cft() which verified that the specified file is a regular
cgroupfs file before further accesses. The cftype pointer returned from
__file_cft() was no longer necessary and the commit inadvertently dropped
the file type check with it allowing any file to slip through. With the
invarients broken, the d_name and parent accesses can now race against
renames and removals of arbitrary files and cause use-after-free's.
Fix the bug by resurrecting the file type check in __file_cft(). Now that
cgroupfs is implemented through kernfs, checking the file operations needs
to go through a layer of indirection. Instead, let's check the superblock
and dentry type.
Link: https://lkml.kernel.org/r/Y5FRm/cfcKPGzWwl@slm.duckdns.org
Fixes: 347c4a874710 ("memcg: remove cgroup_event->cft")
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Jann Horn <jannh@google.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: <stable@vger.kernel.org> [3.14+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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For dax pud, pud_huge() returns true on x86. So the function works as long
as hugetlb is configured. However, dax doesn't depend on hugetlb.
Commit 414fd080d125 ("mm/gup: fix gup_pmd_range() for dax") fixed
devmap-backed huge PMDs, but missed devmap-backed huge PUDs. Fix this as
well.
This fixes the below kernel panic:
general protection fault, probably for non-canonical address 0x69e7c000cc478: 0000 [#1] SMP
< snip >
Call Trace:
<TASK>
get_user_pages_fast+0x1f/0x40
iov_iter_get_pages+0xc6/0x3b0
? mempool_alloc+0x5d/0x170
bio_iov_iter_get_pages+0x82/0x4e0
? bvec_alloc+0x91/0xc0
? bio_alloc_bioset+0x19a/0x2a0
blkdev_direct_IO+0x282/0x480
? __io_complete_rw_common+0xc0/0xc0
? filemap_range_has_page+0x82/0xc0
generic_file_direct_write+0x9d/0x1a0
? inode_update_time+0x24/0x30
__generic_file_write_iter+0xbd/0x1e0
blkdev_write_iter+0xb4/0x150
? io_import_iovec+0x8d/0x340
io_write+0xf9/0x300
io_issue_sqe+0x3c3/0x1d30
? sysvec_reschedule_ipi+0x6c/0x80
__io_queue_sqe+0x33/0x240
? fget+0x76/0xa0
io_submit_sqes+0xe6a/0x18d0
? __fget_light+0xd1/0x100
__x64_sys_io_uring_enter+0x199/0x880
? __context_tracking_enter+0x1f/0x70
? irqentry_exit_to_user_mode+0x24/0x30
? irqentry_exit+0x1d/0x30
? __context_tracking_exit+0xe/0x70
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fc97c11a7be
< snip >
</TASK>
---[ end trace 48b2e0e67debcaeb ]---
RIP: 0010:internal_get_user_pages_fast+0x340/0x990
< snip >
Kernel panic - not syncing: Fatal exception
Kernel Offset: disabled
Link: https://lkml.kernel.org/r/1670392853-28252-1-git-send-email-ssengar@linux.microsoft.com
Fixes: 414fd080d125 ("mm/gup: fix gup_pmd_range() for dax")
Signed-off-by: John Starks <jostarks@microsoft.com>
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Add more sanity checks to the VMA that do_brk_flags() will expand. Ensure
the VMA matches basic merge requirements within the function before
calling can_vma_merge_after().
Drop the duplicate checks from vm_brk_flags() since they will be enforced
later.
The old code would expand file VMAs on brk(), which is functionally
wrong and also dangerous in terms of locking because the brk() path
isn't designed for file VMAs and therefore doesn't lock the file
mapping. Checking can_vma_merge_after() ensures that new anonymous
VMAs can't be merged into file VMAs.
See https://lore.kernel.org/linux-mm/CAG48ez1tJZTOjS_FjRZhvtDA-STFmdw8PEizPDwMGFd_ui0Nrw@mail.gmail.com/
Link: https://lkml.kernel.org/r/20221205192304.1957418-1-Liam.Howlett@oracle.com
Fixes: 2e7ce7d354f2 ("mm/mmap: change do_brk_flags() to expand existing VMA and add do_brk_munmap()")
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Suggested-by: Jann Horn <jannh@google.com>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Fix tmpfs data loss when the fallocate system call is interrupted by a
signal, or fails for some other reason. The partial folio handling in
shmem_undo_range() forgot to consider this unfalloc case, and was liable
to erase or truncate out data which had already been committed earlier.
It turns out that none of the partial folio handling there is appropriate
for the unfalloc case, which just wants to proceed to removal of whole
folios: which find_get_entries() provides, even when partially covered.
Original patch by Rui Wang.
Link: https://lore.kernel.org/linux-mm/33b85d82.7764.1842e9ab207.Coremail.chenguoqic@163.com/
Link: https://lkml.kernel.org/r/a5dac112-cf4b-7af-a33-f386e347fd38@google.com
Fixes: b9a8a4195c7d ("truncate,shmem: Handle truncates that split large folios")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reported-by: Guoqi Chen <chenguoqic@163.com>
Link: https://lore.kernel.org/all/20221101032248.819360-1-kernel@hev.cc/
Cc: Rui Wang <kernel@hev.cc>
Cc: Huacai Chen <chenhuacai@loongson.cn>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: <stable@vger.kernel.org> [5.17+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The following program will trigger the BUG_ON that this patch removes,
because the user can munmap() mm->brk:
#include <sys/syscall.h>
#include <sys/mman.h>
#include <assert.h>
#include <unistd.h>
static void *brk_now(void)
{
return (void *)syscall(SYS_brk, 0);
}
static void brk_set(void *b)
{
assert(syscall(SYS_brk, b) != -1);
}
int main(int argc, char *argv[])
{
void *b = brk_now();
brk_set(b + 4096);
assert(munmap(b - 4096, 4096 * 2) == 0);
brk_set(b);
return 0;
}
Compile that with musl, since glibc actually uses brk(), and then
execute it, and it'll hit this splat:
kernel BUG at mm/mmap.c:229!
invalid opcode: 0000 [#1] PREEMPT SMP
CPU: 12 PID: 1379 Comm: a.out Tainted: G S U 6.1.0-rc7+ #419
RIP: 0010:__do_sys_brk+0x2fc/0x340
Code: 00 00 4c 89 ef e8 04 d3 fe ff eb 9a be 01 00 00 00 4c 89 ff e8 35 e0 fe ff e9 6e ff ff ff 4d 89 a7 20>
RSP: 0018:ffff888140bc7eb0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00000000007e7000 RCX: ffff8881020fe000
RDX: ffff8881020fe001 RSI: ffff8881955c9b00 RDI: ffff8881955c9b08
RBP: 0000000000000000 R08: ffff8881955c9b00 R09: 00007ffc77844000
R10: 0000000000000000 R11: 0000000000000001 R12: 00000000007e8000
R13: 00000000007e8000 R14: 00000000007e7000 R15: ffff8881020fe000
FS: 0000000000604298(0000) GS:ffff88901f700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000603fe0 CR3: 000000015ba9a005 CR4: 0000000000770ee0
PKRU: 55555554
Call Trace:
<TASK>
do_syscall_64+0x2b/0x50
entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x400678
Code: 10 4c 8d 41 08 4c 89 44 24 10 4c 8b 01 8b 4c 24 08 83 f9 2f 77 0a 4c 8d 4c 24 20 4c 01 c9 eb 05 48 8b>
RSP: 002b:00007ffc77863890 EFLAGS: 00000212 ORIG_RAX: 000000000000000c
RAX: ffffffffffffffda RBX: 000000000040031b RCX: 0000000000400678
RDX: 00000000004006a1 RSI: 00000000007e6000 RDI: 00000000007e7000
RBP: 00007ffc77863900 R08: 0000000000000000 R09: 00000000007e6000
R10: 00007ffc77863930 R11: 0000000000000212 R12: 00007ffc77863978
R13: 00007ffc77863988 R14: 0000000000000000 R15: 0000000000000000
</TASK>
Instead, just return the old brk value if the original mapping has been
removed.
[akpm@linux-foundation.org: fix changelog, per Liam]
Link: https://lkml.kernel.org/r/20221202162724.2009-1-Jason@zx2c4.com
Fixes: 2e7ce7d354f2 ("mm/mmap: change do_brk_flags() to expand existing VMA and add do_brk_munmap()")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 updates for 6.2
- Enable the per-vcpu dirty-ring tracking mechanism, together with an
option to keep the good old dirty log around for pages that are
dirtied by something other than a vcpu.
- Switch to the relaxed parallel fault handling, using RCU to delay
page table reclaim and giving better performance under load.
- Relax the MTE ABI, allowing a VMM to use the MAP_SHARED mapping
option, which multi-process VMMs such as crosvm rely on.
- Merge the pKVM shadow vcpu state tracking that allows the hypervisor
to have its own view of a vcpu, keeping that state private.
- Add support for the PMUv3p5 architecture revision, bringing support
for 64bit counters on systems that support it, and fix the
no-quite-compliant CHAIN-ed counter support for the machines that
actually exist out there.
- Fix a handful of minor issues around 52bit VA/PA support (64kB pages
only) as a prefix of the oncoming support for 4kB and 16kB pages.
- Add/Enable/Fix a bunch of selftests covering memslots, breakpoints,
stage-2 faults and access tracking. You name it, we got it, we
probably broke it.
- Pick a small set of documentation and spelling fixes, because no
good merge window would be complete without those.
As a side effect, this tag also drags:
- The 'kvmarm-fixes-6.1-3' tag as a dependency to the dirty-ring
series
- A shared branch with the arm64 tree that repaints all the system
registers to match the ARM ARM's naming, and resulting in
interesting conflicts
|
|
Ext4 needs this function to allow safe migration for journalled data
pages.
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221207112722.22220-11-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
memcg_write_event_control() accesses the dentry->d_name of the specified
control fd to route the write call. As a cgroup interface file can't be
renamed, it's safe to access d_name as long as the specified file is a
regular cgroup file. Also, as these cgroup interface files can't be
removed before the directory, it's safe to access the parent too.
Prior to 347c4a874710 ("memcg: remove cgroup_event->cft"), there was a
call to __file_cft() which verified that the specified file is a regular
cgroupfs file before further accesses. The cftype pointer returned from
__file_cft() was no longer necessary and the commit inadvertently
dropped the file type check with it allowing any file to slip through.
With the invarients broken, the d_name and parent accesses can now race
against renames and removals of arbitrary files and cause
use-after-free's.
Fix the bug by resurrecting the file type check in __file_cft(). Now
that cgroupfs is implemented through kernfs, checking the file
operations needs to go through a layer of indirection. Instead, let's
check the superblock and dentry type.
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 347c4a874710 ("memcg: remove cgroup_event->cft")
Cc: stable@kernel.org # v3.14+
Reported-by: Jann Horn <jannh@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
This reverts commit f35b5d7d676e59e401690b678cd3cfec5e785c23.
It has been reported to cause huge performance regressions on some loads
(will-it-scale.per_process_ops, but also building the kernel with
clang).
The commit did speed up gcc builds by a small amount, so it's not an
unambiguous regression, but until the big regressions are understood,
let's revert it.
Reported-by: kernel test robot <yujie.liu@intel.com>
Link: https://lore.kernel.org/r/202210181535.7144dd15-yujie.liu@intel.com
Reported-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/lkml/Y1DNQaoPWxE%2BrGce@dev-arch.thelio-3990X/
Cc: Huang, Ying <ying.huang@intel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc hotfixes from Andrew Morton:
"15 hotfixes, 11 marked cc:stable.
Only three or four of the latter address post-6.0 issues, which is
hopefully a sign that things are converging"
* tag 'mm-hotfixes-stable-2022-12-02' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
revert "kbuild: fix -Wimplicit-function-declaration in license_is_gpl_compatible"
Kconfig.debug: provide a little extra FRAME_WARN leeway when KASAN is enabled
drm/amdgpu: temporarily disable broken Clang builds due to blown stack-frame
mm/khugepaged: invoke MMU notifiers in shmem/file collapse paths
mm/khugepaged: fix GUP-fast interaction by sending IPI
mm/khugepaged: take the right locks for page table retraction
mm: migrate: fix THP's mapcount on isolation
mm: introduce arch_has_hw_nonleaf_pmd_young()
mm: add dummy pmd_young() for architectures not having it
mm/damon/sysfs: fix wrong empty schemes assumption under online tuning in damon_sysfs_set_schemes()
tools/vm/slabinfo-gnuplot: use "grep -E" instead of "egrep"
nilfs2: fix NULL pointer dereference in nilfs_palloc_commit_free_entry()
hugetlb: don't delete vma_lock in hugetlb MADV_DONTNEED processing
madvise: use zap_page_range_single for madvise dontneed
mm: replace VM_WARN_ON to pr_warn if the node is offline with __GFP_THISNODE
|
|
Several run-time checkers (KASAN, UBSAN, KFENCE, KCSAN, sched) roll
their own warnings, and each check "panic_on_warn". Consolidate this
into a single function so that future instrumentation can be added in
a single location.
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Gow <davidgow@google.com>
Cc: tangmeng <tangmeng@uniontech.com>
Cc: Jann Horn <jannh@google.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: kasan-dev@googlegroups.com
Cc: linux-mm@kvack.org
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/20221117234328.594699-4-keescook@chromium.org
|
|
With all "silently resizing" callers of ksize() refactored, remove the
logic in ksize() that would allow it to be used to effectively change
the size of an allocation (bypassing __alloc_size hints, etc). Users
wanting this feature need to either use kmalloc_size_roundup() before an
allocation, or use krealloc() directly.
For kfree_sensitive(), move the unpoisoning logic inline. Replace the
some of the partially open-coded ksize() in __do_krealloc with ksize()
now that it doesn't perform unpoisoning.
Adjust the KUnit tests to match the new ksize() behavior. Execution
tested with:
$ ./tools/testing/kunit/kunit.py run \
--kconfig_add CONFIG_KASAN=y \
--kconfig_add CONFIG_KASAN_GENERIC=y \
--arch x86_64 kasan
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: linux-mm@kvack.org
Cc: kasan-dev@googlegroups.com
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Enhanced-by: Andrey Konovalov <andreyknvl@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
|
|
If freeit is true, the value of ret must be zero, there is no need to
check the value of freeit after label unlock_mutex.
We can drop variable freeit to do this cleanup.
Link: https://lkml.kernel.org/r/20221125065444.3462681-1-mawupeng1@huawei.com
Signed-off-by: Ma Wupeng <mawupeng1@huawei.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: zhenwei pi <pizhenwei@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
We used to have 624a2c94f5b7 (Partly revert "mm/thp: carry over dirty bit
when thp splits on pmd") fixing the regression reported here by Anatoly
Pugachev on sparc64:
https://lore.kernel.org/r/20221021160603.GA23307@u164.east.ru
Where we temporarily ignored the dirty bit for small pages.
Then, Hev also reported similar issue on loongarch:
(the original mail was private, but Anatoly copied the list here)
https://lore.kernel.org/r/CADxRZqxqb7f_WhMh=jweZP+ynf_JwGd-0VwbYgp4P+T0-AXosw@mail.gmail.com
Hev pointed out that the issue is having HW write bit set within the
pte_mkdirty() so the split pte can be written after split even if e.g.
they were shared by more than one processes, causing data corrupt.
Hev also tried to explain why loongarch set HW write bit in mkdirty:
https://lore.kernel.org/r/CAHirt9itKO_K_HPboXh5AyJtt16Zf0cD73PtHvM=na39u_ztxA@mail.gmail.com
One way to fix it is as what Huacai proposed here for loongarch (then we
can re-apply the dirty bit in thp split):
https://lore.kernel.org/r/20221117042532.4064448-1-chenhuacai@loongson.cnn
We may need similar thing for sparc64, though.
For now since we've found the root cause of the dirty bit issue the
simpler solution (which won't lose the dirty bit for small) that will work
for both is we wr-protect after pte_mkdirty(), so the HW write bit can be
persistent after thp split.
Add a comment for wrprotect, so we will not mess up the ordering later.
With 624a2c94f5b7 (Partly revert "mm/thp: carry over dirty bit when thp
splits on pmd") this is not a fix anymore, but just brings back the dirty
bit for thp split safely, so we re-apply the optimization but in safe way.
Provide a Tested-by credit to Hev too (not the exact same patch but the
same outcome) for loongarch.
Link: https://lkml.kernel.org/r/20221125185857.3110155-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Tested-by: Hev <r@hev.cc> # loongarch
Cc: Anatoly Pugachev <matorola@gmail.com>
Cc: Raghavendra K T <raghavendra.kt@amd.com>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Replace open-coded snprintf() with sysfs_emit() to simplify the code.
Link: https://lkml.kernel.org/r/202211241929015476424@zte.com.cn
Signed-off-by: Xu Panda <xu.panda@zte.com.cn>
Signed-off-by: Yang Yang <yang.yang29@zte.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
zswap_frontswap_load() should be called from preemptible context (we even
call mutex_lock() there) and it does not look like we need to do
GFP_ATOMIC allocaion for temp buffer. The same applies to
zswap_writeback_entry().
Use GFP_KERNEL for temporary buffer allocation in both cases.
Link: https://lkml.kernel.org/r/Y3xCTr6ikbtcUr/y@google.com
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Nhat Pham <nphamcs@gmail.com>
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Depending on the memory configuration, isolate_freepages_block() may scan
pages out of the target range and causes panic.
Panic can occur on systems with multiple zones in a single pageblock.
The reason it is rare is that it only happens in special
configurations. Depending on how many similar systems there are, it
may be a good idea to fix this problem for older kernels as well.
The problem is that pfn as argument of fast_isolate_around() could be out
of the target range. Therefore we should consider the case where pfn <
start_pfn, and also the case where end_pfn < pfn.
This problem should have been addressd by the commit 6e2b7044c199 ("mm,
compaction: make fast_isolate_freepages() stay within zone") but there was
an oversight.
Case1: pfn < start_pfn
<at memory compaction for node Y>
| node X's zone | node Y's zone
+-----------------+------------------------------...
pageblock ^ ^ ^
+-----------+-----------+-----------+-----------+...
^ ^ ^
^ ^ end_pfn
^ start_pfn = cc->zone->zone_start_pfn
pfn
<---------> scanned range by "Scan After"
Case2: end_pfn < pfn
<at memory compaction for node X>
| node X's zone | node Y's zone
+-----------------+------------------------------...
pageblock ^ ^ ^
+-----------+-----------+-----------+-----------+...
^ ^ ^
^ ^ pfn
^ end_pfn
start_pfn
<---------> scanned range by "Scan Before"
It seems that there is no good reason to skip nr_isolated pages just after
given pfn. So let perform simple scan from start to end instead of
dividing the scan into "Before" and "After".
Link: https://lkml.kernel.org/r/20221026112438.236336-1-a.naribayashi@fujitsu.com
Fixes: 6e2b7044c199 ("mm, compaction: make fast_isolate_freepages() stay within zone").
Signed-off-by: NARIBAYASHI Akira <a.naribayashi@fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
This adds the min_ratio_fine knob. The knob specifies the values not
based on 1 of 100, but instead 1 per million.
Link: https://lkml.kernel.org/r/20221119005215.3052436-20-shr@devkernel.io
Signed-off-by: Stefan Roesch <shr@devkernel.io>
Cc: Chris Mason <clm@meta.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
This introduces bdi_set_min_ratio_no_scale(). It uses the max
granularity for the ratio. This function by the new sysfs knob
min_ratio_fine.
Link: https://lkml.kernel.org/r/20221119005215.3052436-19-shr@devkernel.io
Signed-off-by: Stefan Roesch <shr@devkernel.io>
Cc: Chris Mason <clm@meta.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
This adds the max_ratio_fine knob. The knob specifies the values not
based on 1 of 100, but instead 1 per million.
Link: https://lkml.kernel.org/r/20221119005215.3052436-17-shr@devkernel.io
Signed-off-by: Stefan Roesch <shr@devkernel.io>
Cc: Chris Mason <clm@meta.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
This introduces bdi_set_max_ratio_no_scale(). It uses the max
granularity for the ratio. This function by the new sysfs knob
max_ratio_fine.
Link: https://lkml.kernel.org/r/20221119005215.3052436-16-shr@devkernel.io
Signed-off-by: Stefan Roesch <shr@devkernel.io>
Cc: Chris Mason <clm@meta.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
bdi has two existing knobs to limit the amount of dirty memory:
min_ratio and max_ratio. However the granularity of the knobs is limited
and often it is more convenient to specify limits in terms of bytes.
This change adds the min_bytes knob.
It does not store the min_bytes value, instead it converts the max_bytes
value to a ratio. The value is therefore more an approximation than an
absolute value.
It also maintains the sum over all the bdi min_ratio values stored in
the variable bdi_min_ratio.
Link: https://lkml.kernel.org/r/20221119005215.3052436-14-shr@devkernel.io
Signed-off-by: Stefan Roesch <shr@devkernel.io>
Cc: Chris Mason <clm@meta.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
This introduces the bdi_set_min_bytes() function. The min_bytes function
does not store the min_bytes value. Instead it converts the min_bytes
value into the corresponding ratio value.
Link: https://lkml.kernel.org/r/20221119005215.3052436-13-shr@devkernel.io
Signed-off-by: Stefan Roesch <shr@devkernel.io>
Cc: Chris Mason <clm@meta.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
This splits off the __bdi_set_min_ratio() function from the
bdi_set_min_ratio() function. The __bdi_set_min_ratio() function will
also be called from the bdi_set_min_bytes() function, which will be
introduced in the next patch.
Link: https://lkml.kernel.org/r/20221119005215.3052436-12-shr@devkernel.io
Signed-off-by: Stefan Roesch <shr@devkernel.io>
Cc: Chris Mason <clm@meta.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
This adds a function to return the specified value for min_bytes. It
converts the stored min_ratio of the bdi to the corresponding bytes
value. This is an approximation as it is based on the value that is
returned by global_dirty_limits(), which can change. The returned
value can be different than the value when the min_bytes value was set.
Link: https://lkml.kernel.org/r/20221119005215.3052436-11-shr@devkernel.io
Signed-off-by: Stefan Roesch <shr@devkernel.io>
Cc: Chris Mason <clm@meta.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
This adds the new knob max_bytes to specify a dirty memory limit for the
corresponding bdi. The specified bytes value is converted to a ratio.
Link: https://lkml.kernel.org/r/20221119005215.3052436-9-shr@devkernel.io
Signed-off-by: Stefan Roesch <shr@devkernel.io>
Cc: Chris Mason <clm@meta.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
This introduces the bdi_set_max_bytes() function. The max_bytes function
does not store the max_bytes value. Instead it converts the max_bytes
value into the corresponding ratio value.
Link: https://lkml.kernel.org/r/20221119005215.3052436-8-shr@devkernel.io
Signed-off-by: Stefan Roesch <shr@devkernel.io>
Cc: Chris Mason <clm@meta.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
This splits off __bdi_set_max_ratio() from bdi_set_max_ratio().
__bdi_set_max_ratio() will also be called from bdi_set_max_bytes(),
which will be introduced in the next patch.
Link: https://lkml.kernel.org/r/20221119005215.3052436-7-shr@devkernel.io
Signed-off-by: Stefan Roesch <shr@devkernel.io>
Cc: Chris Mason <clm@meta.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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This adds a function to return the specified value for max_bytes. It
converts the stored max_ratio of the bdi to the corresponding bytes
value. It introduces the bdi_get_bytes helper function to do the
conversion. This is an approximation as it is based on the value that is
returned by global_dirty_limits(), which can change. The helper function
will also be used by the min_bytes bdi knob.
Link: https://lkml.kernel.org/r/20221119005215.3052436-6-shr@devkernel.io
Signed-off-by: Stefan Roesch <shr@devkernel.io>
Cc: Chris Mason <clm@meta.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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To get finer granularity for ratio calculations use part per million
instead of percentiles. This is especially important if we want to
automatically convert byte values to ratios. Otherwise the values that
are actually used can be quite different. This is also important for
machines with more main memory (1% of 256GB is already 2.5GB).
Link: https://lkml.kernel.org/r/20221119005215.3052436-5-shr@devkernel.io
Signed-off-by: Stefan Roesch <shr@devkernel.io>
Cc: Chris Mason <clm@meta.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Add a new knob to /sys/class/bdi/<bdi>/strict_limit. This new knob
allows to set/unset the flag BDI_CAP_STRICTLIMIT in the bdi
capabilities.
Link: https://lkml.kernel.org/r/20221119005215.3052436-3-shr@devkernel.io
Signed-off-by: Stefan Roesch <shr@devkernel.io>
Cc: Chris Mason <clm@meta.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "mm/block: add bdi sysfs knobs", v4.
At meta network block devices (nbd) are used to implement remote block
storage. In testing and during production it has been observed that these
network block devices can consume a huge portion of the dirty writeback
cache and writeback can take a considerable time.
To be able to give stricter limits, I'm proposing the following changes:
1) introduce strictlimit knob
Currently the max_ratio knob exists to limit the dirty_memory. However
this knob only applies once (dirty_ratio + dirty_background_ratio) / 2
has been reached.
With the BDI_CAP_STRICTLIMIT flag, the max_ratio can be applied without
reaching that limit. This change exposes that knob.
This knob can also be useful for NFS, fuse filesystems and USB devices.
2) Use part of 1000000 internal calculation
The max_ratio is based on percentage. With the current machine sizes
percentage values can be very high (1% of a 256GB main memory is already
2.5GB). This change uses part of 1000000 instead of percentages for the
internal calculations.
3) Introduce two new sysfs knobs: min_bytes and max_bytes.
Currently all calculations are based on ratio, but for a user it often
more convenient to specify a limit in bytes. The new knobs will not
store bytes values, instead they will translate the byte value to a
corresponding ratio. As the internal values are now part of 1000, the
ratio is closer to the specified value. However the value should be more
seen as an approximation as it can fluctuate over time.
3) Introduce two new sysfs knobs: min_ratio_fine and max_ratio_fine.
The granularity for the existing sysfs bdi knobs min_ratio and max_ratio
is based on percentage values. The new sysfs bdi knobs min_ratio_fine
and max_ratio_fine allow to specify the ratio as part of 1 million.
This patch (of 20):
This adds the bdi_set_strict_limit function to be able to set/unset the
BDI_CAP_STRICTLIMIT flag.
Link: https://lkml.kernel.org/r/20221119005215.3052436-1-shr@devkernel.io
Link: https://lkml.kernel.org/r/20221119005215.3052436-2-shr@devkernel.io
Signed-off-by: Stefan Roesch <shr@devkernel.io>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Chris Mason <clm@meta.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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This reverts commit ac801e7e252c5588325e3c983c7d4167fc68c024.
The patch in question was picked to -mm from the KMSAN v6 patch series
(https://lore.kernel.org/linux-mm/20220905122452.2258262-1-glider@google.com/)
and sneaked into mainline despite its removal from the v7 series
(https://lore.kernel.org/linux-mm/20220915150417.722975-1-glider@google.com/)
Currently KMSAN does not warn about origin chains hitting the maximum
depth, so keeping @tlb poisoned won't result in any inconveniences.
Link: https://lkml.kernel.org/r/20221110113541.1844156-1-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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There are no more callers of try_to_release_page(), so remove it. This
saves 85 bytes of kernel text.
Link: https://lkml.kernel.org/r/20221118073055.55694-5-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Replace try_to_release_page() with filemap_release_folio(). This change
is in preparation for the removal of the try_to_release_page() wrapper.
Link: https://lkml.kernel.org/r/20221118073055.55694-4-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Replace some calls with their folio equivalents. This change removes 4
calls to compound_head() and is in preparation for the removal of the
try_to_release_page() wrapper.
Link: https://lkml.kernel.org/r/20221118073055.55694-3-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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While freeing a large list, the zone lock will be released and reacquired
to avoid long hold times since commit c24ad77d962c ("mm/page_alloc.c:
avoid excessive IRQ disabled times in free_unref_page_list()"). As
suggested by Vlastimil Babka, the lockrelease/reacquire logic can be
simplified by reusing the logic that acquires a different lock when
changing zones.
Link: https://lkml.kernel.org/r/20221122131229.5263-3-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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