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Let's get rid of another follow_page() user and perform the UV calls under
PTL -- which likely should be fine.
No need for an additional reference while holding the PTL:
uv_destroy_folio() and uv_convert_from_secure_folio() raise the refcount,
so any concurrent make_folio_secure() would see an unexpted reference and
cannot set PG_arch_1 concurrently.
Do we really need a writable PTE? Likely yes, because the "destroy" part
is, in comparison to the export, a destructive operation. So we'll keep
the writability check for now.
We'll lose the secretmem check from follow_page(). Likely we don't care
about that here.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Reviewed-by: Claudio Imbrenda <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Gerald Schaefer <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Janosch Frank <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Zi Yan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Let's remove yet another follow_page() user. Note that we have to do the
split without holding the PTL, after folio_walk_end(). We don't care
about losing the secretmem check in follow_page().
[[email protected]: teach can_split_folio() that we are not holding an additional reference]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Reviewed-by: Zi Yan <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Claudio Imbrenda <[email protected]>
Cc: Gerald Schaefer <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Janosch Frank <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Ryan Roberts <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Let's use folio_walk instead, for example avoiding taking temporary folio
references if the folio does obviously not even apply and getting rid of
one more follow_page() user. We cannot move all handling under the PTL,
so leave the rmap handling (which implies an allocation) out.
Note that zeropages obviously don't apply: old code could just have
specified FOLL_DUMP. Further, we don't care about losing the secretmem
check in follow_page(): these are never anon pages and
vma_ksm_compatible() would never consider secretmem vmas (VM_SHARED |
VM_MAYSHARE must be set for secretmem, see secretmem_mmap()).
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Claudio Imbrenda <[email protected]>
Cc: Gerald Schaefer <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Janosch Frank <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Zi Yan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Let's use folio_walk instead, for example avoiding taking temporary folio
references if the folio does not even apply and getting rid of one more
follow_page() user.
Note that zeropages obviously don't apply: old code could just have
specified FOLL_DUMP. Anon folios are never secretmem, so we don't care
about losing the check in follow_page().
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Claudio Imbrenda <[email protected]>
Cc: Gerald Schaefer <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Janosch Frank <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Zi Yan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Let's use folio_walk instead, so we can avoid taking a folio reference
when we won't even be trying to migrate the folio and to get rid of
another follow_page()/FOLL_DUMP user. Use FW_ZEROPAGE so we can return
"-EFAULT" for it as documented.
We now perform the folio_likely_mapped_shared() check under PTL, which is
what we want: relying on the mapcount and friends after dropping the PTL
does not make too much sense, as the page can get unmapped concurrently
from this process.
Further, we perform the folio isolation under PTL, similar to how we
handle it for MADV_PAGEOUT.
The possible return values for follow_page() were confusing, especially
with FOLL_DUMP set. We'll handle it like documented in the man page:
* -EFAULT: This is a zero page or the memory area is not mapped by the
process.
* -ENOENT: The page is not present.
We'll keep setting -ENOENT for ZONE_DEVICE. Maybe not the right thing to
do, but it likely doesn't really matter (just like for weird devmap,
whereby we fake "not present").
The other errros are left as is, and match the documentation in the man
page.
While at it, rename add_page_for_migration() to add_folio_for_migration().
We'll lose the "secretmem" check, but that shouldn't really matter because
these folios cannot ever be migrated. Should vma_migratable() refuse
these VMAs? Maybe.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Claudio Imbrenda <[email protected]>
Cc: Gerald Schaefer <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Janosch Frank <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Zi Yan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Let's use folio_walk instead, so we can avoid taking a folio reference
just to read the nid and get rid of another follow_page()/FOLL_DUMP user.
Use FW_ZEROPAGE so we can return "-EFAULT" for it as documented.
The possible return values for follow_page() were confusing, especially
with FOLL_DUMP set. We'll handle it like documented in the man page:
* -EFAULT: This is a zero page or the memory area is not mapped by the
process.
* -ENOENT: The page is not present.
We'll keep setting -ENOENT for ZONE_DEVICE. Maybe not the right thing to
do, but it likely doesn't really matter (just like for weird devmap,
whereby we fake "not present").
Note that the other errors (-EACCESS, -EBUSY, -EIO, -EINVAL, -ENOMEM) so
far only applied when actually moving pages, not when only querying stats.
We'll effectively drop the "secretmem" check we had in follow_page(), but
that shouldn't really matter here, we're not accessing folio/page content
after all.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Claudio Imbrenda <[email protected]>
Cc: Gerald Schaefer <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Janosch Frank <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Zi Yan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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We want to get rid of follow_page(), and have a more reasonable way to
just lookup a folio mapped at a certain address, perform some checks while
still under PTL, and then only conditionally grab a folio reference if
really required.
Further, we might want to get rid of some walk_page_range*() users that
really only want to temporarily lookup a single folio at a single address.
So let's add a new page table walker that does exactly that, similarly to
GUP also being able to walk hugetlb VMAs.
Add folio_walk_end() as a macro for now: the compiler is not easy to
please with the pte_unmap()->kunmap_local().
Note that one difference between follow_page() and get_user_pages(1) is
that follow_page() will not trigger faults to get something mapped. So
folio_walk is at least currently not a replacement for get_user_pages(1),
but could likely be extended/reused to achieve something similar in the
future.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Claudio Imbrenda <[email protected]>
Cc: Gerald Schaefer <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Janosch Frank <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Zi Yan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Patch series "mm: replace follow_page() by folio_walk".
Looking into a way of moving the last folio_likely_mapped_shared() call in
add_folio_for_migration() under the PTL, I found myself removing
follow_page(). This paves the way for cleaning up all the FOLL_, follow_*
terminology to just be called "GUP" nowadays.
The new page table walker will lookup a mapped folio and return to the
caller with the PTL held, such that the folio cannot get unmapped
concurrently. Callers can then conditionally decide whether they really
want to take a short-term folio reference or whether the can simply unlock
the PTL and be done with it.
folio_walk is similar to page_vma_mapped_walk(), except that we don't know
the folio we want to walk to and that we are only walking to exactly one
PTE/PMD/PUD.
folio_walk provides access to the pte/pmd/pud (and the referenced folio
page because things like KSM need that), however, as part of this series
no page table modifications are performed by users.
We might be able to convert some other walk_page_range() users that really
only walk to one address, such as DAMON with
damon_mkold_ops/damon_young_ops. It might make sense to extend folio_walk
in the future to optionally fault in a folio (if applicable), such that we
can replace some get_user_pages() users that really only want to lookup a
single page/folio under PTL without unconditionally grabbing a folio
reference.
I have plans to extend the approach to a range walker that will try
batching various page table entries (not just folio pages) to be a better
replace for walk_page_range() -- and users will be able to opt in which
type of page table entries they want to process -- but that will require
more work and more thoughts.
KSM seems to work just fine (ksm_functional_tests selftests) and
move_pages seems to work (migration selftest). I tested the leaf
implementation excessively using various hugetlb sizes (64K, 2M, 32M, 1G)
on arm64 using move_pages and did some more testing on x86-64. Cross
compiled on a bunch of architectures.
This patch (of 11):
We want to make use of vm_normal_page_pmd() in generic page table walking
code where we might walk hugetlb folios that are mapped by PMDs even
without CONFIG_TRANSPARENT_HUGEPAGE.
So let's expose vm_normal_page_pmd() + vm_normal_folio_pmd() with
CONFIG_PGTABLE_HAS_HUGE_LEAVES.
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Claudio Imbrenda <[email protected]>
Cc: Gerald Schaefer <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Janosch Frank <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Zi Yan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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- we have a helper wmark_pages(). Teach min_wmark_pages(),
low_wmark_pages(), high_wmark_pages() and promo_wmark_pages() to use
it instead of open-coding its implementation.
- there's no reason to implement all these things as macros. Redo them
in C.
Acked-by: Johannes Weiner <[email protected]>
Cc: Kaiyang Zhao <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Print the promo watermark in zoneinfo just like other watermarks. This
helps users check and verify all the watermarks are appropriate.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Kaiyang Zhao <[email protected]>
Cc: Johannes Weiner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Patch series "mm: print the promo watermark in zoneinfo", v2.
This patch (of 2):
Define promo_wmark_pages and convert current call sites of wmark_pages
with fixed WMARK_PROMO to using it instead.
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Kaiyang Zhao <[email protected]>
Cc: Johannes Weiner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Currently in migrate_balanced_pgdat(), ALLOC_CMA flag is not passed when
checking watermark on the migration target node. This does not match the
gfp in alloc_misplaced_dst_folio() which allows allocation from CMA.
This causes promotion failures when there are a lot of available CMA
memory in the system.
Therefore, we change the alloc_flags passed to zone_watermark_ok() in
migrate_balanced_pgdat().
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Kaiyang Zhao <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Reviewed-by: Baolin Wang <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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This patch fixes the zswap global shrinker, which did not shrink the zpool
as expected.
The issue addressed is that shrink_worker() did not distinguish between
unexpected errors and expected errors, such as failed writeback from an
empty memcg. The shrinker would stop shrinking after iterating through
the memcg tree 16 times, even if there was only one empty memcg.
With this patch, the shrinker no longer considers encountering an empty
memcg, encountering a memcg with writeback disabled, or reaching the end
of a memcg tree walk as a failure, as long as there are memcgs that are
candidates for writeback. Systems with one or more empty memcgs will now
observe significantly higher zswap writeback activity after the zswap pool
limit is hit.
To avoid an infinite loop when there are no writeback candidates, this
patch tracks writeback attempts during memcg tree walks and limits reties
if no writeback candidates are found.
To handle the empty memcg case, the helper function shrink_memcg() is
modified to check if the memcg is empty and then return -ENOENT.
Link: https://lkml.kernel.org/r/[email protected]
Fixes: a65b0e7607cc ("zswap: make shrinking memcg-aware")
Signed-off-by: Takero Funaki <[email protected]>
Reviewed-by: Chengming Zhou <[email protected]>
Reviewed-by: Nhat Pham <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Yosry Ahmed <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Patch series "mm: zswap: fixes for global shrinker", v5.
This series addresses issues in the zswap global shrinker that could not
shrink stored pages. With this series, the shrinker continues to shrink
pages until it reaches the accept threshold more reliably, gives much
higher writeback when the zswap pool limit is hit.
This patch (of 2):
This patch fixes an issue where the zswap global shrinker stopped
iterating through the memcg tree.
The problem was that shrink_worker() would restart iterating memcg tree
from the tree root, considering an offline memcg as a failure, and abort
shrinking after encountering the same offline memcg 16 times even if there
is only one offline memcg. After this change, an offline memcg in the
tree is no longer considered a failure. This allows the shrinker to
continue shrinking the other online memcgs regardless of whether an
offline memcg exists, gives higher zswap writeback activity.
To avoid holding refcount of offline memcg encountered during the memcg
tree walking, shrink_worker() must continue iterating to release the
offline memcg to ensure the next memcg stored in the cursor is online.
The offline memcg cleaner has also been changed to avoid the same issue.
When the next memcg of the offlined memcg is also offline, the refcount
stored in the iteration cursor was held until the next shrink_worker()
run. The cleaner must release the offline memcg recursively.
[[email protected]: make critical section more obvious, unify comments]
Link: https://lkml.kernel.org/r/CAJD7tkaScz+SbB90Q1d5mMD70UfM2a-J2zhXDT9sePR7Qap45Q@mail.gmail.com
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: a65b0e7607cc ("zswap: make shrinking memcg-aware")
Signed-off-by: Takero Funaki <[email protected]>
Signed-off-by: Yosry Ahmed <[email protected]>
Acked-by: Yosry Ahmed <[email protected]>
Reviewed-by: Chengming Zhou <[email protected]>
Reviewed-by: Nhat Pham <[email protected]>
Cc: Chengming Zhou <[email protected]>
Cc: Johannes Weiner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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It should be checked by filemap_get_folio() if SWAP_HAS_CACHE was
marked while reading a share swap page. It would re-allocate a folio
if the swap cache was not ready now. We save the new folio to avoid
page allocating again.
Link: https://lkml.kernel.org/r/20240731133101.GA2096752@bytedance
Signed-off-by: Zhaoyu Liu <[email protected]>
Cc: Domenico Cerasuolo <[email protected]>
Cc: Kairui Song <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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For KSM folios, the function actually does what it is supposed to do: even
having multiple mappings inside the same MM is considered "sharing", as
there is no real relationship between these KSM page mappings -- in
contrast to mapping the same file range twice and having the same
pagecache page mapped twice.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Let's simplify and reduce code indentation. In the RMAP_LEVEL_PTE case,
we already check for nr when computing partially_mapped.
For RMAP_LEVEL_PMD, it's a bit more confusing. Likely, we don't need the
"nr" check, but we could have "nr < nr_pmdmapped" also if we stumbled into
the "/* Raced ahead of another remove and an add? */" case. So let's
simply move the nr check in there.
Note that partially_mapped is always false for small folios.
No functional change intended.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Reviewed-by: Zi Yan <[email protected]>
Reviewed-by: Yosry Ahmed <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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We removed hugetlb_follow_page_mask() in commit 9cb28da54643 ("mm/gup:
handle hugetlb in the generic follow_page_mask code") but forgot to
cleanup some leftovers.
While at it, simplify the hugetlb comment, it's overly detailed and rather
confusing. Stating that we may end up in there during coredumping is
sufficient to explain the PF_DUMPCORE usage.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Reviewed-by: Peter Xu <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Jan Kara <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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After commit 73db3abdca58 ("init/modpost: conditionally check section
mismatch to __meminit*"), we can get rid of __ref annotations.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Wei Yang <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Cc: Masahiro Yamada <[email protected]>
Cc: Oscar Salvador <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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support large folios
Right now, swapcache_prepare() and swapcache_clear() supports one entry
only, to support large folios, we need to handle multiple swap entries.
To optimize stack usage, we iterate twice in __swap_duplicate(): the first
time to verify that all entries are valid, and the second time to apply
the modifications to the entries.
Currently, we're using nr=1 for the existing users.
[[email protected]: clarify swap_count_continued and improve readability for __swap_duplicate]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Barry Song <[email protected]>
Reviewed-by: Baolin Wang <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Tested-by: Baolin Wang <[email protected]>
Cc: Chris Li <[email protected]>
Cc: Gao Xiang <[email protected]>
Cc: "Huang, Ying" <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Kairui Song <[email protected]>
Cc: Kalesh Singh <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Nhat Pham <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Sergey Senozhatsky <[email protected]>
Cc: Shakeel Butt <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Yang Shi <[email protected]>
Cc: Yosry Ahmed <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Compiling z3fold.c results in several sparse warnings:
z3fold.c:797:21: warning: incorrect type in initializer (different address spaces)
z3fold.c:797:21: expected void const [noderef] __percpu *__vpp_verify
z3fold.c:797:21: got struct list_head *
z3fold.c:852:37: warning: incorrect type in initializer (different address spaces)
z3fold.c:852:37: expected void const [noderef] __percpu *__vpp_verify
z3fold.c:852:37: got struct list_head *
z3fold.c:924:25: warning: incorrect type in assignment (different address spaces)
z3fold.c:924:25: expected struct list_head *unbuddied
z3fold.c:924:25: got void [noderef] __percpu *_res
z3fold.c:930:33: warning: incorrect type in initializer (different address spaces)
z3fold.c:930:33: expected void const [noderef] __percpu *__vpp_verify
z3fold.c:930:33: got struct list_head *
z3fold.c:949:25: warning: incorrect type in argument 1 (different address spaces)
z3fold.c:949:25: expected void [noderef] __percpu *__pdata
z3fold.c:949:25: got struct list_head *unbuddied
z3fold.c:979:25: warning: incorrect type in argument 1 (different address spaces)
z3fold.c:979:25: expected void [noderef] __percpu *__pdata
z3fold.c:979:25: got struct list_head *unbuddied
Add __percpu annotation to *unbuddied pointer to fix these warnings.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Uros Bizjak <[email protected]>
Reviewed-by: Miaohe Lin <[email protected]>
Cc: Vitaly Wool <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Replace the unnecessary division calculation with cma->count when update
the value of totalcma_pages.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Hao Ge <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Replace direct access to zoneref->zone, zoneref->zone_idx, or
zone_to_nid(zoneref->zone) with the corresponding zonelist_* helper
functions for consistency.
No functional change.
Link: https://lkml.kernel.org/r/[email protected]
Co-developed-by: Shivank Garg <[email protected]>
Signed-off-by: Shivank Garg <[email protected]>
Signed-off-by: Wei Yang <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Cc: Mike Rapoport (IBM) <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Establish a new userland VMA unit testing implementation under
tools/testing which utilises existing logic providing maple tree support
in userland utilising the now-shared code previously exclusive to radix
tree testing.
This provides fundamental VMA operations whose API is defined in mm/vma.h,
while stubbing out superfluous functionality.
This exists as a proof-of-concept, with the test implementation functional
and sufficient to allow userland compilation of vma.c, but containing only
cursory tests to demonstrate basic functionality.
Link: https://lkml.kernel.org/r/533ffa2eec771cbe6b387dd049a7f128a53eb616.1722251717.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <[email protected]>
Tested-by: SeongJae Park <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Reviewed-by: Liam R. Howlett <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Brendan Higgins <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: David Gow <[email protected]>
Cc: Eric W. Biederman <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Rae Moar <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Pengfei Xu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
|
|
The core components contained within the radix-tree tests which provide
shims for kernel headers and access to the maple tree are useful for
testing other things, so separate them out and make the radix tree tests
dependent on the shared components.
This lays the groundwork for us to add VMA tests of the newly introduced
vma.c file.
Link: https://lkml.kernel.org/r/1ee720c265808168e0d75608e687607d77c36719.1722251717.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Reviewed-by: Liam R. Howlett <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Brendan Higgins <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: David Gow <[email protected]>
Cc: Eric W. Biederman <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Rae Moar <[email protected]>
Cc: SeongJae Park <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Pengfei Xu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
|
|
The vma files contain logic split from mmap.c for the most part and are
all relevant to VMA logic, so maintain the same reviewers for both.
Link: https://lkml.kernel.org/r/bf2581cce2b4d210deabb5376c6aa0ad6facf1ff.1722251717.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Acked-by: Liam R. Howlett <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Brendan Higgins <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: David Gow <[email protected]>
Cc: Eric W. Biederman <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Rae Moar <[email protected]>
Cc: SeongJae Park <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Pengfei Xu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
|
|
This patch introduces vma.c and moves internal core VMA manipulation
functions to this file from mmap.c.
This allows us to isolate VMA functionality in a single place such that we
can create userspace testing code that invokes this functionality in an
environment where we can implement simple unit tests of core
functionality.
This patch ensures that core VMA functionality is explicitly marked as
such by its presence in mm/vma.h.
It also places the header includes required by vma.c in vma_internal.h,
which is simply imported by vma.c. This makes the VMA functionality
testable, as userland testing code can simply stub out functionality as
required.
Link: https://lkml.kernel.org/r/c77a6aafb4c42aaadb8e7271a853658cbdca2e22.1722251717.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <[email protected]>
Reviewed-by: Vlastimil Babka <[email protected]>
Reviewed-by: Liam R. Howlett <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Brendan Higgins <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: David Gow <[email protected]>
Cc: Eric W. Biederman <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Rae Moar <[email protected]>
Cc: SeongJae Park <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Pengfei Xu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
|
|
The vma_shrink() and vma_expand() functions are internal VMA manipulation
functions which we ought to abstract for use outside of memory management
code.
To achieve this, we replace shift_arg_pages() in fs/exec.c with an
invocation of a new relocate_vma_down() function implemented in mm/mmap.c,
which enables us to also move move_page_tables() and vma_iter_prev_range()
to internal.h.
The purpose of doing this is to isolate key VMA manipulation functions in
order that we can both abstract them and later render them easily
testable.
Link: https://lkml.kernel.org/r/3cfcd9ec433e032a85f636fdc0d7d98fafbd19c5.1722251717.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <[email protected]>
Reviewed-by: Vlastimil Babka <[email protected]>
Reviewed-by: Liam R. Howlett <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Brendan Higgins <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: David Gow <[email protected]>
Cc: Eric W. Biederman <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Rae Moar <[email protected]>
Cc: SeongJae Park <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Pengfei Xu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
|
|
These are core VMA manipulation functions which invoke VMA splitting and
merging and should not be directly accessed from outside of mm/.
Link: https://lkml.kernel.org/r/5efde0c6342a8860d5ffc90b415f3989fd8ed0b2.1722251717.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <[email protected]>
Reviewed-by: Vlastimil Babka <[email protected]>
Reviewed-by: Liam R. Howlett <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Brendan Higgins <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: David Gow <[email protected]>
Cc: Eric W. Biederman <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Rae Moar <[email protected]>
Cc: SeongJae Park <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Pengfei Xu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
|
|
Patch series "Make core VMA operations internal and testable", v4.
There are a number of "core" VMA manipulation functions implemented in
mm/mmap.c, notably those concerning VMA merging, splitting, modifying,
expanding and shrinking, which logically don't belong there.
More importantly this functionality represents an internal implementation
detail of memory management and should not be exposed outside of mm/
itself.
This patch series isolates core VMA manipulation functionality into its
own file, mm/vma.c, and provides an API to the rest of the mm code in
mm/vma.h.
Importantly, it also carefully implements mm/vma_internal.h, which
specifies which headers need to be imported by vma.c, leading to the very
useful property that vma.c depends only on mm/vma.h and mm/vma_internal.h.
This means we can then re-implement vma_internal.h in userland, adding
shims for kernel mechanisms as required, allowing us to unit test internal
VMA functionality.
This testing is useful as opposed to an e.g. kunit implementation as this
way we can avoid all external kernel side-effects while testing, run tests
VERY quickly, and iterate on and debug problems quickly.
Excitingly this opens the door to, in the future, recreating precise
problems observed in production in userland and very quickly debugging
problems that might otherwise be very difficult to reproduce.
This patch series takes advantage of existing shim logic and full userland
maple tree support contained in tools/testing/radix-tree/ and
tools/include/linux/, separating out shared components of the radix tree
implementation to provide this testing.
Kernel functionality is stubbed and shimmed as needed in
tools/testing/vma/ which contains a fully functional userland
vma_internal.h file and which imports mm/vma.c and mm/vma.h to be directly
tested from userland.
A simple, skeleton testing implementation is provided in
tools/testing/vma/vma.c as a proof-of-concept, asserting that simple VMA
merge, modify (testing split), expand and shrink functionality work
correctly.
This patch (of 4):
This patch forms part of a patch series intending to separate out VMA
logic and render it testable from userspace, which requires that core
manipulation functions be exposed in an mm/-internal header file.
In order to do this, we must abstract APIs we wish to test, in this
instance functions which ultimately invoke vma_modify().
This patch therefore moves all logic which ultimately invokes vma_modify()
to mm/userfaultfd.c, trying to transfer code at a functional granularity
where possible.
[[email protected]: fix user-after-free in userfaultfd_clear_vma()]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/50c3ed995fd81c45876c86304c8a00bf3e396cfd.1722251717.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <[email protected]>
Reviewed-by: Vlastimil Babka <[email protected]>
Reviewed-by: Liam R. Howlett <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Brendan Higgins <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: David Gow <[email protected]>
Cc: Eric W. Biederman <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Rae Moar <[email protected]>
Cc: SeongJae Park <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Pengfei Xu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
|
|
Extend two existing tests to cover extracting memory usage through the
newly mutable memory.peak and memory.swap.peak handlers.
In particular, make sure to exercise adding and removing watchers with
overlapping lifetimes so the less-trivial logic gets tested.
The new/updated tests attempt to detect a lack of the write handler by
fstat'ing the memory.peak and memory.swap.peak files and skip the tests if
that's the case. Additionally, skip if the file doesn't exist at all.
[[email protected]: update tests]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Finkel <[email protected]>
Acked-by: Tejun Heo <[email protected]>
Reviewed-by: Roman Gushchin <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Michal Koutný <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Shakeel Butt <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Waiman Long <[email protected]>
Cc: Zefan Li <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
|
|
Patch series "mm, memcg: cg2 memory{.swap,}.peak write handlers", v7.
This patch (of 2):
Other mechanisms for querying the peak memory usage of either a process or
v1 memory cgroup allow for resetting the high watermark. Restore parity
with those mechanisms, but with a less racy API.
For example:
- Any write to memory.max_usage_in_bytes in a cgroup v1 mount resets
the high watermark.
- writing "5" to the clear_refs pseudo-file in a processes's proc
directory resets the peak RSS.
This change is an evolution of a previous patch, which mostly copied the
cgroup v1 behavior, however, there were concerns about races/ownership
issues with a global reset, so instead this change makes the reset
filedescriptor-local.
Writing any non-empty string to the memory.peak and memory.swap.peak
pseudo-files reset the high watermark to the current usage for subsequent
reads through that same FD.
Notably, following Johannes's suggestion, this implementation moves the
O(FDs that have written) behavior onto the FD write(2) path. Instead, on
the page-allocation path, we simply add one additional watermark to
conditionally bump per-hierarchy level in the page-counter.
Additionally, this takes Longman's suggestion of nesting the
page-charging-path checks for the two watermarks to reduce the number of
common-case comparisons.
This behavior is particularly useful for work scheduling systems that need
to track memory usage of worker processes/cgroups per-work-item. Since
memory can't be squeezed like CPU can (the OOM-killer has opinions), these
systems need to track the peak memory usage to compute system/container
fullness when binpacking workitems.
Most notably, Vimeo's use-case involves a system that's doing global
binpacking across many Kubernetes pods/containers, and while we can use
PSI for some local decisions about overload, we strive to avoid packing
workloads too tightly in the first place. To facilitate this, we track
the peak memory usage. However, since we run with long-lived workers (to
amortize startup costs) we need a way to track the high watermark while a
work-item is executing. Polling runs the risk of missing short spikes
that last for timescales below the polling interval, and peak memory
tracking at the cgroup level is otherwise perfect for this use-case.
As this data is used to ensure that binpacked work ends up with sufficient
headroom, this use-case mostly avoids the inaccuracies surrounding
reclaimable memory.
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Finkel <[email protected]>
Suggested-by: Johannes Weiner <[email protected]>
Suggested-by: Waiman Long <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Reviewed-by: Michal Koutný <[email protected]>
Acked-by: Tejun Heo <[email protected]>
Reviewed-by: Roman Gushchin <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Shakeel Butt <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Zefan Li <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
|
|
All code was converted to using arch_make_folio_accessible(), let's drop
arch_make_page_accessible().
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Reviewed-by: Matthew Wilcox (Oracle) <[email protected]>
Reviewed-by: Vishal Moola (Oracle) <[email protected]>
Reviewed-by: Claudio Imbrenda <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Janosch Frank <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
|
|
Let's use arch_make_folio_accessible() instead so we can get rid of
arch_make_page_accessible().
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Reviewed-by: Matthew Wilcox (Oracle) <[email protected]>
Reviewed-by: Vishal Moola (Oracle) <[email protected]>
Reviewed-by: Claudio Imbrenda <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Janosch Frank <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
|
|
Patch series "mm: remove arch_make_page_accessible()".
Now that s390x implements arch_make_folio_accessible(), let's convert
remaining users to use arch_make_folio_accessible() instead so we can
remove arch_make_page_accessible().
This patch (of 3):
Now that s390x implements HAVE_ARCH_MAKE_FOLIO_ACCESSIBLE, let's turn
generic arch_make_folio_accessible() into a NOP: there are no other
targets that implement HAVE_ARCH_MAKE_PAGE_ACCESSIBLE but not
HAVE_ARCH_MAKE_FOLIO_ACCESSIBLE.
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Reviewed-by: Matthew Wilcox (Oracle) <[email protected]>
Reviewed-by: Vishal Moola (Oracle) <[email protected]>
Reviewed-by: Claudio Imbrenda <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Janosch Frank <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
|
|
Use min() to simplify the dmirror_exclusive() function and improve its
readability.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Thorsten Blum <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Cc: Jérôme Glisse <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
|
|
Right now, we cannot have split PT locks because 8xx does not support SMP.
But for the sake of documentation *why* 8xx is fine regarding what we
documented in huge_pte_lockptr(), let's just add code to enforce it at the
same time as documenting it.
This should also make everybody who wants to copy from the 8xx approach of
supporting such unusual ways of mapping hugetlb folios aware that it gets
tricky once multiple page tables are involved.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Mike Rapoport (Microsoft) <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: "Naveen N. Rao" <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Russell King <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
|
|
Sharing page tables between processes but falling back to per-MM page
table locks cannot possibly work.
So, let's make sure that we do have split PMD locks by adding a new
Kconfig option and letting that depend on CONFIG_SPLIT_PMD_PTLOCKS.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Acked-by: Mike Rapoport (Microsoft) <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: "Naveen N. Rao" <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Russell King <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
|
|
Patch series "mm: split PTE/PMD PT table Kconfig cleanups+clarifications".
This series is a follow up to the fixes:
"[PATCH v1 0/2] mm/hugetlb: fix hugetlb vs. core-mm PT locking"
When working on the fixes, I wondered why 8xx is fine (-> never uses split
PT locks) and how PT locking even works properly with PMD page table
sharing (-> always requires split PMD PT locks).
Let's improve the split PT lock detection, make hugetlb properly depend on
it and make 8xx bail out if it would ever get enabled by accident.
As an alternative to patch #3 we could extend the Kconfig
SPLIT_PTE_PTLOCKS option from patch #2 -- but enforcing it closer to the
code that actually implements it feels a bit nicer for documentation
purposes, and there is no need to actually disable it because it should
always be disabled (!SMP).
Did a bunch of cross-compilations to make sure that split PTE/PMD PT locks
are still getting used where we would expect them.
[1] https://lkml.kernel.org/r/[email protected]
This patch (of 3):
Let's clean that up a bit and prepare for depending on
CONFIG_SPLIT_PMD_PTLOCKS in other Kconfig options.
More cleanups would be reasonable (like the arch-specific "depends on" for
CONFIG_SPLIT_PTE_PTLOCKS), but we'll leave that for another day.
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Acked-by: Mike Rapoport (Microsoft) <[email protected]>
Reviewed-by: Russell King (Oracle) <[email protected]>
Reviewed-by: Qi Zheng <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: "Naveen N. Rao" <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
|
|
When a page_counter structure is initialized, there is no need to use an
atomic set operation to initialize the usage counter because at this point
the structure is not visible to anybody else. ATOMIC_LONG_INIT() is what
should be used in such cases.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Roman Gushchin <[email protected]>
Acked-by: Shakeel Butt <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Muchun Song <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
|
|
Put page_counter_calculate_protection() under CONFIG_MEMCG.
The protection functionality (min/low limits) is not supported by any
other cgroup subsystem, so page_counter_calculate_protection() and related
static effective_protection() can be compiled out if CONFIG_MEMCG is not
enabled.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Roman Gushchin <[email protected]>
Acked-by: Shakeel Butt <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Muchun Song <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
|
|
Patch series "mm: memcg: page counters optimizations", v3.
This patchset contains 3 independent small optimizations of page counters.
This patch (of 3):
Memory protection (min/low) requires a constant tracking of protected
memory usage. propagate_protected_usage() is called on each page counters
update and does a number of operations even in cases when the actual
memory protection functionality is not supported (e.g. hugetlb cgroups or
memcg swap counters).
It's obviously inefficient and leads to a waste of CPU cycles. It can be
addressed by calling propagate_protected_usage() only for the counters
which do support memory guarantees. As of now it's only memcg->memory -
the unified memory memcg counter.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Roman Gushchin <[email protected]>
Acked-by: Shakeel Butt <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Muchun Song <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
|
|
The comment is useless after commit 57a196a58421 ("hugetlb: simplify
hugetlb handling in follow_page_mask") since all follow_huge_foo() are
killed.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Kefeng Wang <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Reviewed-by: Vishal Moola (Oracle) <[email protected]>
Cc: Muchun Song <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
|
|
Add a per-CPU memory leak, which will be reported like:
unreferenced object 0x3efa840195f8 (size 64):
comm "modprobe", pid 4667, jiffies 4294688677
hex dump (first 32 bytes on cpu 0):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace (crc 0):
[<ffffffffa7fa87af>] pcpu_alloc+0x3df/0x840
[<ffffffffc11642d9>] kmemleak_test_init+0x2c9/0x2f0 [kmemleak_test]
[<ffffffffa7c02264>] do_one_initcall+0x44/0x300
[<ffffffffa7de9e10>] do_init_module+0x60/0x240
[<ffffffffa7deb946>] init_module_from_file+0x86/0xc0
[<ffffffffa7deba99>] idempotent_init_module+0x109/0x2a0
[<ffffffffa7debd2a>] __x64_sys_finit_module+0x5a/0xb0
[<ffffffffa88f4f3a>] do_syscall_64+0x7a/0x160
[<ffffffffa8a0012b>] entry_SYSCALL_64_after_hwframe+0x76/0x7e
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Pavel Tikhomirov <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
Cc: Alexander Mikhalitsyn <[email protected]>
Cc: Chen Jun <[email protected]>
Cc: Wei Yongjun <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Patch series "kmemleak: support for percpu memory leak detect'.
This is a rework of this series:
https://lore.kernel.org/lkml/[email protected]/
Originally I was investigating a percpu leak on our customer nodes and
having this functionality was a huge help, which lead to this fix [1].
So probably it's a good idea to have it in mainstream too, especially as
after [2] it became much easier to implement (we already have a separate
tree for percpu pointers).
[1] commit 0af8c09c89681 ("netfilter: x_tables: fix percpu counter block leak on error path when creating new netns")
[2] commit 39042079a0c24 ("kmemleak: avoid RCU stalls when freeing metadata for per-CPU pointers")
This patch (of 2):
This basically does:
- Add min_percpu_addr and max_percpu_addr to filter out unrelated data
similar to min_addr and max_addr;
- Set min_count for percpu pointers to 1 to start tracking them;
- Calculate checksum of percpu area as xor of crc32 for each cpu;
- Split pointer lookup and update refs code into separate helper and use
it twice: once as if the pointer is a virtual pointer and once as if
it's percpu.
[[email protected]: v2]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Pavel Tikhomirov <[email protected]>
Reviewed-by: Catalin Marinas <[email protected]>
Cc: Wei Yongjun <[email protected]>
Cc: Chen Jun <[email protected]>
Cc: Alexander Mikhalitsyn <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Given that stack_not_used() is not performance critical function
uninline it.
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Pasha Tatashin <[email protected]>
Acked-by: Shakeel Butt <[email protected]>
Cc: Domenico Cerasuolo <[email protected]>
Cc: Kent Overstreet <[email protected]>
Cc: Li Zhijian <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Nhat Pham <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Zi Yan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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As part of the dynamic kernel stack project, we need to know the amount of
data that can be saved by reducing the default kernel stack size [1].
Provide a kernel stack usage histogram to aid in optimizing kernel stack
sizes and minimizing memory waste in large-scale environments. The
histogram divides stack usage into power-of-two buckets and reports the
results in /proc/vmstat. This information is especially valuable in
environments with millions of machines, where even small optimizations can
have a significant impact.
The histogram data is presented in /proc/vmstat with entries like
"kstack_1k", "kstack_2k", and so on, indicating the number of threads that
exited with stack usage falling within each respective bucket.
Example outputs:
Intel:
$ grep kstack /proc/vmstat
kstack_1k 3
kstack_2k 188
kstack_4k 11391
kstack_8k 243
kstack_16k 0
ARM with 64K page_size:
$ grep kstack /proc/vmstat
kstack_1k 1
kstack_2k 340
kstack_4k 25212
kstack_8k 1659
kstack_16k 0
kstack_32k 0
kstack_64k 0
Note: once the dynamic kernel stack is implemented it will depend on the
implementation the usability of this feature: On hardware that supports
faults on kernel stacks, we will have other metrics that show the total
number of pages allocated for stacks. On hardware where faults are not
supported, we will most likely have some optimization where only some
threads are extended, and for those, these metrics will still be very
useful.
[1] https://lwn.net/Articles/974367
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Pasha Tatashin <[email protected]>
Reviewed-by: Kent Overstreet <[email protected]>
Acked-by: Shakeel Butt <[email protected]>
Cc: Domenico Cerasuolo <[email protected]>
Cc: Li Zhijian <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Nhat Pham <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Zi Yan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Patch series "Kernel stack usage histogram", v6.
Provide histogram of stack sizes for the exited threads:
Example outputs:
Intel:
$ grep kstack /proc/vmstat
kstack_1k 3
kstack_2k 188
kstack_4k 11391
kstack_8k 243
kstack_16k 0
ARM with 64K page_size:
$ grep kstack /proc/vmstat
kstack_1k 1
kstack_2k 340
kstack_4k 25212
kstack_8k 1659
kstack_16k 0
kstack_32k 0
kstack_64k 0
This patch (of 3):
At the moment the valid index for the indirection tables for memcg stats
and events is < S8_MAX. These indirection tables are used in performance
critical codepaths. With the latest addition to the vm_events, the
NR_VM_EVENT_ITEMS has gone over S8_MAX. One way to resolve is to increase
the entry size of the indirection table from int8_t to int16_t but this
will increase the potential number of cachelines needed to access the
indirection table.
This patch took a different approach and make the valid index < U8_MAX.
In this way the size of the indirection tables will remain same and we
only need to invalid index check from less than 0 to equal to U8_MAX. In
this approach we have also removed a subtraction from the performance
critical codepaths.
[[email protected]: v6]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Shakeel Butt <[email protected]>
Co-developed-by: Pasha Tatashin <[email protected]>
Signed-off-by: Pasha Tatashin <[email protected]>
Cc: Domenico Cerasuolo <[email protected]>
Cc: Kent Overstreet <[email protected]>
Cc: Li Zhijian <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Nhat Pham <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Zi Yan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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The releasing process of the non-shared anonymous folio mapped solely by
an exiting process may go through two flows: 1) the anonymous folio is
firstly is swaped-out into swapspace and transformed into a swp_entry in
shrink_folio_list; 2) then the swp_entry is released in the process
exiting flow. This will result in the high cpu load of releasing a
non-shared anonymous folio mapped solely by an exiting process.
When the low system memory and the exiting process exist at the same time,
it will be likely to happen, because the non-shared anonymous folio mapped
solely by an exiting process may be reclaimed by shrink_folio_list.
This patch is that shrink skips the non-shared anonymous folio solely
mapped by an exting process and this folio is only released directly in
the process exiting flow, which will save swap-out time and alleviate the
load of the process exiting.
Barry provided some effectiveness testing in [1]. "I observed that
this patch effectively skipped 6114 folios (either 4KB or 64KB mTHP),
potentially reducing the swap-out by up to 92MB (97,300,480 bytes)
during the process exit. The working set size is 256MB."
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lore.kernel.org/linux-mm/[email protected]/ [1]
Signed-off-by: Zhiguo Jiang <[email protected]>
Acked-by: Barry Song <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Remove boilerplate by using a macro to choose the corresponding lock and
handler for each folio_batch in cpu_fbatches.
[[email protected]: handle zero-length local_lock_t]
Link: https://lkml.kernel.org/r/[email protected]
[[email protected]: fix "BUG: using smp_processor_id() in preemptible"]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Yu Zhao <[email protected]>
Tested-by: Hugh Dickins <[email protected]>
Cc: Barry Song <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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