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25197 Commits
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c4408277c0 |
mm/filemap: do not use is_partially_uptodate for entire folio
Patch series "Tiny optimization for large read operations". This series contains two patches, 1. Skip calling is_partially_uptodate for entire folio to save time, I have reviewed the mpage and iomap implementations and didn't spot any issues, but this change likely needs more thorough review. 2. Skip calling filemap_uptodate if there are ready folios in the batch, This might save a few milliseconds in practice, but I didn't observe measurable improvements in my tests. This patch (of 2): When a folio is marked as non-uptodate, it means the folio contains some non-uptodate data. Therefore, calling is_partially_uptodate() to recheck the entire folio is redundant. If all data in a folio is actually up-to-date but the folio lacks the uptodate flag, it will still be treated as non-uptodate in many other places. Thus, there should be no special case handling for filemap. Link: https://lkml.kernel.org/r/20250728083952.75518-1-chizhiling@163.com Link: https://lkml.kernel.org/r/20250728083952.75518-2-chizhiling@163.com Signed-off-by: Chi Zhiling <chizhiling@kylinos.cn> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Jan Kara <jack@suse.cz> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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f6a4a150f1 |
mm/damon/tests/core-kunit: add damos_commit_filter test
Add unit test to verify that damos_commmit_filter() change dest value well. Link: https://lkml.kernel.org/r/20250817021348.570692-1-ekffu200098@gmail.com Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com> Reviewed-by: SeongJae Park <sj@kernel.org> Cc: Honggyu Kim <honggyu.kim@sk.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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4bd22a7ae5 |
mm: fix duplicate accounting of free pages in should_reclaim_retry()
In the zone_reclaimable_pages() function, if the page counts for
NR_ZONE_INACTIVE_FILE, NR_ZONE_ACTIVE_FILE, NR_ZONE_INACTIVE_ANON, and
NR_ZONE_ACTIVE_ANON are all zero, the function returns the number of free
pages as the result.
In this case, when should_reclaim_retry() calculates reclaimable pages, it
will inadvertently double-count the free pages in its accounting.
static inline bool
should_reclaim_retry(gfp_t gfp_mask, unsigned order,
struct alloc_context *ac, int alloc_flags,
bool did_some_progress, int *no_progress_loops)
{
...
available = reclaimable = zone_reclaimable_pages(zone);
available += zone_page_state_snapshot(zone, NR_FREE_PAGES);
This may result in an increase in the number of retries of
__alloc_pages_slowpath(), causing increased kswapd load.
Link: https://lkml.kernel.org/r/20250812070210.1624218-1-liuqiqi@kylinos.cn
Fixes:
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88df6ab2f3 |
mm: add folio_is_pci_p2pdma()
Reimplement is_pci_p2pdma_page() in terms of folio_is_pci_p2pdma(). Moves the page_folio() call from inside page_pgmap() to is_pci_p2pdma_page(). This removes a page_folio() call from try_grab_folio() which already has a folio and can pass it in. Link: https://lkml.kernel.org/r/20250805172307.1302730-12-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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11afccce2a |
slab: use memdesc_nid()
We no longer need to convert from slab to folio to get the nid, we can ask memdesc_nid() for the nid directly. Link: https://lkml.kernel.org/r/20250805172307.1302730-7-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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87479378ac |
slab: use memdesc_flags_t
The slab flags are memdesc flags and contain the same information in the upper bits as the other memdescs (like node ID). Link: https://lkml.kernel.org/r/20250805172307.1302730-6-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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eb00fdd84d |
mm: introduce memdesc_nid()
Remove a conversion from folio to page by passing the folio->flags (which are a copy of the page->flags) to the new memdesc_nid() function. Link: https://lkml.kernel.org/r/20250805172307.1302730-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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56d578c130 |
mm: convert page_to_section() to memdesc_section()
Pass in the memdesc_flags_t instead of a pointer to the page. This will allow us to remove a few conversions to struct page in upcoming patches. Link: https://lkml.kernel.org/r/20250805172307.1302730-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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53fbef56e0 |
mm: introduce memdesc_flags_t
Patch series "Add and use memdesc_flags_t". At some point struct page will be separated from struct slab and struct folio. This is a step towards that by introducing a type for the 'flags' word of all three structures. This gives us a certain amount of type safety by establishing that some of these unsigned longs are different from other unsigned longs in that they contain things like node ID, section number and zone number in the upper bits. That lets us have functions that can be easily called by anyone who has a slab, folio or page (but not easily by anyone else) to get the node or zone. There's going to be some unusual merge problems with this as some odd bits of the kernel decide they want to print out the flags value or something similar by writing page->flags and now they'll need to write page->flags.f instead. That's most of the churn here. Maybe we should be removing these things from the debug output? This patch (of 11): Wrap the unsigned long flags in a typedef. In upcoming patches, this will provide a strong hint that you can't just pass a random unsigned long to functions which take this as an argument. [willy@infradead.org: s/flags/flags.f/ in several architectures] Link: https://lkml.kernel.org/r/aKMgPRLD-WnkPxYm@casper.infradead.org [nicola.vetrini@gmail.com: mips: fix compilation error] Link: https://lore.kernel.org/lkml/CA+G9fYvkpmqGr6wjBNHY=dRp71PLCoi2341JxOudi60yqaeUdg@mail.gmail.com/ Link: https://lkml.kernel.org/r/20250825214245.1838158-1-nicola.vetrini@gmail.com Link: https://lkml.kernel.org/r/20250805172307.1302730-1-willy@infradead.org Link: https://lkml.kernel.org/r/20250805172307.1302730-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Zi Yan <ziy@nvidia.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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4e915656a3 |
mm/damon/Kconfig: make DAMON_STAT_ENABLED_DEFAULT depend on DAMON_STAT
The DAMON_STAT_ENABLED_DEFAULT option is strongly tied to DAMON_STAT
option -- enabling it alone is meaningless. This patch makes
DAMON_STAT_ENABLED_DEFAULT depend on DAMON_STAT, ensuring functional
consistency.
Link: https://lkml.kernel.org/r/20250815092110.811757-1-lienze@kylinos.cn
Fixes:
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8cdc4d2701 |
mm/huge_memory: respect MADV_COLLAPSE with PR_THP_DISABLE_EXCEPT_ADVISED
Let's allow for making MADV_COLLAPSE succeed on areas that neither have VM_HUGEPAGE nor VM_NOHUGEPAGE when we have THP disabled unless explicitly advised (PR_THP_DISABLE_EXCEPT_ADVISED). MADV_COLLAPSE is a clear advice that we want to collapse. Note that we still respect the VM_NOHUGEPAGE flag, just like MADV_COLLAPSE always does. So consequently, MADV_COLLAPSE is now only refused on VM_NOHUGEPAGE with PR_THP_DISABLE_EXCEPT_ADVISED, including for shmem. Link: https://lkml.kernel.org/r/20250815135549.130506-4-usamaarif642@gmail.com Co-developed-by: Usama Arif <usamaarif642@gmail.com> Signed-off-by: Usama Arif <usamaarif642@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Barry Song <baohua@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Rik van Riel <riel@surriel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: SeongJae Park <sj@kernel.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yafang <laoar.shao@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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1f1c061089 |
mm/huge_memory: convert "tva_flags" to "enum tva_type"
When determining which THP orders are eligible for a VMA mapping, we have previously specified tva_flags, however it turns out it is really not necessary to treat these as flags. Rather, we distinguish between distinct modes. The only case where we previously combined flags was with TVA_ENFORCE_SYSFS, but we can avoid this by observing that this is the default, except for MADV_COLLAPSE or an edge cases in collapse_pte_mapped_thp() and hugepage_vma_revalidate(), and adding a mode specifically for this case - TVA_FORCED_COLLAPSE. We have: * smaps handling for showing "THPeligible" * Pagefault handling * khugepaged handling * Forced collapse handling: primarily MADV_COLLAPSE, but also for an edge case in collapse_pte_mapped_thp() Disregarding the edge cases, we only want to ignore sysfs settings only when we are forcing a collapse through MADV_COLLAPSE, otherwise we want to enforce it, hence this patch does the following flag to enum conversions: * TVA_SMAPS | TVA_ENFORCE_SYSFS -> TVA_SMAPS * TVA_IN_PF | TVA_ENFORCE_SYSFS -> TVA_PAGEFAULT * TVA_ENFORCE_SYSFS -> TVA_KHUGEPAGED * 0 -> TVA_FORCED_COLLAPSE With this change, we immediately know if we are in the forced collapse case, which will be valuable next. Link: https://lkml.kernel.org/r/20250815135549.130506-3-usamaarif642@gmail.com Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Usama Arif <usamaarif642@gmail.com> Acked-by: Usama Arif <usamaarif642@gmail.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Barry Song <baohua@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Rik van Riel <riel@surriel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: SeongJae Park <sj@kernel.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yafang <laoar.shao@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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9dc21bbd62 |
prctl: extend PR_SET_THP_DISABLE to optionally exclude VM_HUGEPAGE
Patch series "prctl: extend PR_SET_THP_DISABLE to only provide THPs when
advised", v5.
This will allow individual processes to opt-out of THP = "always" into THP
= "madvise", without affecting other workloads on the system. This has
been extensively discussed on the mailing list and has been summarized
very well by David in the first patch which also includes the links to
alternatives, please refer to the first patch commit message for the
motivation for this series.
Patch 1 adds the PR_THP_DISABLE_EXCEPT_ADVISED flag to implement this,
along with the MMF changes.
Patch 2 is a cleanup patch for tva_flags that will allow the forced
collapse case to be transmitted to vma_thp_disabled (which is done in
patch 3).
Patch 4 adds documentation for PR_SET_THP_DISABLE/PR_GET_THP_DISABLE.
Patches 6-7 implement the selftests for PR_SET_THP_DISABLE for completely
disabling THPs (old behaviour) and only enabling it at advise
(PR_THP_DISABLE_EXCEPT_ADVISED).
This patch (of 7):
People want to make use of more THPs, for example, moving from the "never"
system policy to "madvise", or from "madvise" to "always".
While this is great news for every THP desperately waiting to get
allocated out there, apparently there are some workloads that require a
bit of care during that transition: individual processes may need to
opt-out from this behavior for various reasons, and this should be
permitted without needing to make all other workloads on the system
similarly opt-out.
The following scenarios are imaginable:
(1) Switch from "none" system policy to "madvise"/"always", but keep THPs
disabled for selected workloads.
(2) Stay at "none" system policy, but enable THPs for selected
workloads, making only these workloads use the "madvise" or "always"
policy.
(3) Switch from "madvise" system policy to "always", but keep the
"madvise" policy for selected workloads: allocate THPs only when
advised.
(4) Stay at "madvise" system policy, but enable THPs even when not advised
for selected workloads -- "always" policy.
Once can emulate (2) through (1), by setting the system policy to
"madvise"/"always" while disabling THPs for all processes that don't want
THPs. It requires configuring all workloads, but that is a user-space
problem to sort out.
(4) can be emulated through (3) in a similar way.
Back when (1) was relevant in the past, as people started enabling THPs,
we added PR_SET_THP_DISABLE, so relevant workloads that were not ready yet
(i.e., used by Redis) were able to just disable THPs completely. Redis
still implements the option to use this interface to disable THPs
completely.
With PR_SET_THP_DISABLE, we added a way to force-disable THPs for a
workload -- a process, including fork+exec'ed process hierarchy. That
essentially made us support (1): simply disable THPs for all workloads
that are not ready for THPs yet, while still enabling THPs system-wide.
The quest for handling (3) and (4) started, but current approaches
(completely new prctl, options to set other policies per process,
alternatives to prctl -- mctrl, cgroup handling) don't look particularly
promising. Likely, the future will use bpf or something similar to
implement better policies, in particular to also make better decisions
about THP sizes to use, but this will certainly take a while as that work
just started.
Long story short: a simple enable/disable is not really suitable for the
future, so we're not willing to add completely new toggles.
While we could emulate (3)+(4) through (1)+(2) by simply disabling THPs
completely for these processes, this is a step backwards, because these
processes can no longer allocate THPs in regions where THPs were
explicitly advised: regions flagged as VM_HUGEPAGE. Apparently, that
imposes a problem for relevant workloads, because "not THPs" is certainly
worse than "THPs only when advised".
Could we simply relax PR_SET_THP_DISABLE, to "disable THPs unless not
explicitly advised by the app through MAD_HUGEPAGE"? *maybe*, but this
would change the documented semantics quite a bit, and the versatility to
use it for debugging purposes, so I am not 100% sure that is what we want
-- although it would certainly be much easier.
So instead, as an easy way forward for (3) and (4), add an option to
make PR_SET_THP_DISABLE disable *less* THPs for a process.
In essence, this patch:
(A) Adds PR_THP_DISABLE_EXCEPT_ADVISED, to be used as a flag in arg3
of prctl(PR_SET_THP_DISABLE) when disabling THPs (arg2 != 0).
prctl(PR_SET_THP_DISABLE, 1, PR_THP_DISABLE_EXCEPT_ADVISED).
(B) Makes prctl(PR_GET_THP_DISABLE) return 3 if
PR_THP_DISABLE_EXCEPT_ADVISED was set while disabling.
Previously, it would return 1 if THPs were disabled completely. Now
it returns the set flags as well: 3 if PR_THP_DISABLE_EXCEPT_ADVISED
was set.
(C) Renames MMF_DISABLE_THP to MMF_DISABLE_THP_COMPLETELY, to express
the semantics clearly.
Fortunately, there are only two instances outside of prctl() code.
(D) Adds MMF_DISABLE_THP_EXCEPT_ADVISED to express "no THP except for VMAs
with VM_HUGEPAGE" -- essentially "thp=madvise" behavior
Fortunately, we only have to extend vma_thp_disabled().
(E) Indicates "THP_enabled: 0" in /proc/pid/status only if THPs are
disabled completely
Only indicating that THPs are disabled when they are really disabled
completely, not only partially.
For now, we don't add another interface to obtained whether THPs
are disabled partially (PR_THP_DISABLE_EXCEPT_ADVISED was set). If
ever required, we could add a new entry.
The documented semantics in the man page for PR_SET_THP_DISABLE "is
inherited by a child created via fork(2) and is preserved across
execve(2)" is maintained. This behavior, for example, allows for
disabling THPs for a workload through the launching process (e.g., systemd
where we fork() a helper process to then exec()).
For now, MADV_COLLAPSE will *fail* in regions without VM_HUGEPAGE and
VM_NOHUGEPAGE. As MADV_COLLAPSE is a clear advise that user space thinks
a THP is a good idea, we'll enable that separately next (requiring a bit
of cleanup first).
There is currently not way to prevent that a process will not issue
PR_SET_THP_DISABLE itself to re-enable THP. There are not really known
users for re-enabling it, and it's against the purpose of the original
interface. So if ever required, we could investigate just forbidding to
re-enable them, or make this somehow configurable.
Link: https://lkml.kernel.org/r/20250815135549.130506-1-usamaarif642@gmail.com
Link: https://lkml.kernel.org/r/20250815135549.130506-2-usamaarif642@gmail.com
Acked-by: Zi Yan <ziy@nvidia.com>
Acked-by: Usama Arif <usamaarif642@gmail.com>
Tested-by: Usama Arif <usamaarif642@gmail.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Usama Arif <usamaarif642@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yafang <laoar.shao@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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e338d83531 |
mm: readahead: improve mmap_miss heuristic for concurrent faults
If two or more threads of an application faulting on the same folio, the mmap_miss counter can be decreased multiple times. It breaks the mmap_miss heuristic and keeps the readahead enabled even under extreme levels of memory pressure. It happens often if file folios backing a multi-threaded application are getting evicted and re-faulted. Fix it by skipping decreasing mmap_miss if the folio is locked. This change was evaluated on several hundred thousands hosts in Google's production over a couple of weeks. The number of containers being stuck in a vicious reclaim cycle for a long time was reduced several fold (~10-20x), as well as the overall fleet-wide cpu time spent in direct memory reclaim was meaningfully reduced. No regressions were observed. Link: https://lkml.kernel.org/r/20250815183224.62007-1-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Jan Kara <jack@suse.cz> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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5922deb3ec |
mm/page_alloc: remove redundant pcp->free_count initialization in per_cpu_pages_init()
In per_cpu_pages_init(), pcp->free_count is explicitly initialized to 0, but this is redundant because the entire struct is already zeroed by memset(pcp, 0, sizeof(*pcp)). Link: https://lkml.kernel.org/r/20250814071828.12036-1-ye.liu@linux.dev Signed-off-by: Ye Liu <liuye@kylinos.cn> Reviewed-by: Brendan Jackman <jackmanb@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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e4fe1388df |
mm: fix typos in VMA comments
Fix the following typos in VMA-related files: 1. "operationr" -> "operation" in mm/vma.h 2. "initialisaing" -> "initializing" in mm/vma_init.c Link: https://lkml.kernel.org/r/20250814073800.13617-1-ye.liu@linux.dev Signed-off-by: Ye Liu <liuye@kylinos.cn> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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0c04015d45 |
mm/page_alloc: simplify lowmem_reserve max calculation
Use max() to find the maximum lowmem_reserve value and min_t() to cap it to managed_pages in calculate_totalreserve_pages(), instead of open-coding the comparisons. No functional change. [liuye@kylinos.cn: fix layout, use min_t] Link: https://lkml.kernel.org/r/20250815024509.37900-1-ye.liu@linux.dev Link: https://lkml.kernel.org/r/20250814090053.22241-1-ye.liu@linux.dev Signed-off-by: Ye Liu <liuye@kylinos.cn> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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6a204d4b14 |
mm/page_alloc: only set ALLOC_HIGHATOMIC for __GPF_HIGH allocations
Commit |
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ec45783fce |
memcg: optimize exit to user space
memcg uses TIF_NOTIFY_RESUME to handle reclaiming on exit to user space. TIF_NOTIFY_RESUME is a multiplexing TIF bit, which is utilized by other entities as well. This results in a unconditional mem_cgroup_handle_over_high() call for every invocation of resume_user_mode_work(), which is a pointless exercise as most of the time there is no reclaim work to do. Especially since RSEQ is used by glibc, TIF_NOTIFY_RESUME is raised quite frequently and the empty calls show up in exit path profiling. Optimize this by doing a quick check of the reclaim condition before invoking it. [akpm@linux-foundation.org: remove now-unneeded test of memcg_nr_pages_over_high==0, per Shakeel] Link: https://lkml.kernel.org/r/87tt2b6zgs.ffs@tglx Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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5094469205 |
userfaultfd: opportunistic TLB-flush batching for present pages in MOVE
MOVE ioctl's runtime is dominated by TLB-flush cost, which is required for moving present pages. Mitigate this cost by opportunistically batching present contiguous pages for TLB flushing. Without batching, in our testing on an arm64 Android device with UFFD GC, which uses MOVE ioctl for compaction, we observed that out of the total time spent in move_pages_pte(), over 40% is in ptep_clear_flush(), and ~20% in vm_normal_folio(). With batching, the proportion of vm_normal_folio() increases to over 70% of move_pages_pte() without any changes to vm_normal_folio(). Furthermore, time spent within move_pages_pte() is only ~20%, which includes TLB-flush overhead. When the GC intensive benchmark, which was used to gather the above numbers, is run on cuttlefish (qemu android instance on x86_64), the completion time of the benchmark went down from ~45mins to ~20mins. Furthermore, system_server, one of the most performance critical system processes on android, saw over 50% reduction in GC compaction time on an arm64 android device. [lokeshgidra@google.com: make calculation of largest extent that can be batched unconditional on length, per Barry] Link: https://lkml.kernel.org/r/20250816191123.3601561-1-lokeshgidra@google.com Link: https://lkml.kernel.org/r/20250813193024.2279805-1-lokeshgidra@google.com Signed-off-by: Lokesh Gidra <lokeshgidra@google.com> Acked-by: Peter Xu <peterx@redhat.com> Reviewed-by: Barry Song <baohua@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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348e474f18 |
mm/swapfile.c: introduce function alloc_swap_scan_list()
Patch series "mm/swapfile.c and swap.h cleanup", v3. This patch series, which builds on Kairui's swap improve cluster scan series. https://lore.kernel.org/linux-mm/20250806161748.76651-1-ryncsn@gmail.com/ It introduces a new function, alloc_swap_scan_list(), for swapfile.c. It also cleans up swap.h by removing comments that reference fields that have been deleted. There are no functional changes in this two-patch series. This patch (of 2): alloc_swap_scan_list() will scan the whole list or the first cluster. This reduces the repeat patterns of isolating a cluster then scanning that cluster. As a result, cluster_alloc_swap_entry() is shorter and shallower. No functional change. Link: https://lkml.kernel.org/r/20250812-swap-scan-list-v3-0-6d73504d267b@kernel.org Link: https://lkml.kernel.org/r/20250812-swap-scan-list-v3-1-6d73504d267b@kernel.org Signed-off-by: Chris Li <chrisl@kernel.org> Reviewed-by: Kairui Song <kasong@tencent.com> Acked-by: Nhat Pham <nphamcs@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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dca4437a58 |
mm/zswap: store <PAGE_SIZE compression failed page as-is
When zswap writeback is enabled and it fails compressing a given page, the
page is swapped out to the backing swap device. This behavior breaks the
zswap's writeback LRU order, and hence users can experience unexpected
latency spikes. If the page is compressed without failure, but results in
a size of PAGE_SIZE, the LRU order is kept, but the decompression overhead
for loading the page back on the later access is unnecessary.
Keep the LRU order and optimize unnecessary decompression overheads in
those cases, by storing the original content as-is in zpool. The length
field of zswap_entry will be set appropriately, as PAGE_SIZE. Hence
whether it is saved as-is or not (whether decompression is unnecessary) is
identified by 'zswap_entry->length == PAGE_SIZE'.
Because the uncompressed data is saved in zpool, same to the compressed
ones, this introduces no change in terms of memory management including
movability and migratability of involved pages.
This change is also not increasing per zswap entry metadata overhead. But
as the number of incompressible pages increases, total zswap metadata
overhead is proportionally increased. The overhead should not be
problematic in usual cases, since the zswap metadata for single zswap
entry is much smaller than PAGE_SIZE, and in common zswap use cases there
should be a sufficient amount of compressible pages. Also it can be
mitigated by the zswap writeback.
When the writeback is disabled, the additional overhead could be
problematic. For the case, keep the current behavior that just returns
the failure and let swap_writeout() put the page back to the active LRU
list in the case.
Knowing how many incompressible pages are stored at the given moment will
be useful for future investigations. Add a new debugfs file called
stored_incompressible_pages for the purpose.
Tests
-----
I tested this patch using a simple self-written microbenchmark that is
available at GitHub[1]. You can reproduce the test I did by executing
run_tests.sh of the repo on your system. Note that the repo's
documentation is not good as of this writing, so you may need to read and
use the code.
The basic test scenario is simple. Run a test program making artificial
accesses to memory having artificial content under memory.high-set memory
limit and measure how many accesses were made in a given time.
The test program repeatedly and randomly access three anonymous memory
regions. The regions are all 500 MiB size, and be accessed in the same
probability. Two of those are filled up with a simple content that can
easily be compressed, while the remaining one is filled up with a content
that s read from /dev/urandom, which is easy to fail at compressing to a
size smaller than PAGE_SIZE. The program runs for two minutes and prints
out the number of accesses made every five seconds.
The test script runs the program under below four configurations.
- 0: memory.high is set to 2 GiB, zswap is disabled.
- 1-1: memory.high is set to 1350 MiB, zswap is disabled.
- 1-2: On 1-1, zswap is enabled without this patch.
- 1-3: On 1-2, this patch is applied.
For all zswap enabled cases, zswap shrinker is enabled.
Configuration '0' is for showing the original memory performance.
Configurations 1-1, 1-2 and 1-3 are for showing the performance of swap,
zswap, and this patch under a level of memory pressure (~10% of working
set). Configurations 0 and 1-1 are not the main focus of this patch, but
I'm adding those since their results transparently show how far this
microbenchmark test is from the real world.
Because the per-5 seconds performance is not very reliable, I measured the
average of that for the last one minute period of the test program run. I
also measured a few vmstat counters including zswpin, zswpout, zswpwb,
pswpin and pswpout during the test runs.
The measurement results are as below. To save space, I show performance
numbers that are normalized to that of the configuration '0' (no memory
pressure). The averaged accesses per 5 seconds of configuration '0' was
36493417.75.
config 0 1-1 1-2 1-3
perf_normalized 1.0000 0.0057 0.0235 0.0367
perf_stdev_ratio 0.0582 0.0652 0.0167 0.0346
zswpin 0 0 3548424 1999335
zswpout 0 0 3588817 2361689
zswpwb 0 0 10214 340270
pswpin 0 485806 772038 340967
pswpout 0 649543 144773 340270
'perf_normalized' is the performance metric, normalized to that of
configuration '0' (no pressure). 'perf_stdev_ratio' is the standard
deviation of the averaged data points, as a ratio to the averaged metric
value. For example, configuration '0' performance was showing 5.8% stdev.
Configurations 1-1 and 1-3 were having about 6.5% and 6.1% stdev. Also
the results were highly variable between multiple runs. So this result is
not very stable but just showing ball park figures. Please keep this in
your mind when reading these results.
Under about 10% of working set memory pressure, the performance was
dropped to about 0.57% of no-pressure one, when the normal swap is used
(1-1). Note that ~10% working set pressure is already extreme, at least
on this test setup. No one would desire system setups that can degrade
performance to 0.57% of the best case.
By turning zswap on (1-2), the performance was improved about 4x,
resulting in about 2.35% of no-pressure one. Because of the
incompressible pages in the third memory region, a significant amount of
(non-zswap) swap I/O operations were made, though.
By applying this patch (1-3), about 56% performance improvement was made,
resulting in about 3.67% of no-pressure one. Reduced pswpin of 1-3
compared to 1-2 let us see where this improvement came from.
Tests without Zswap Shrinker
----------------------------
Zswap shrinker is not enabled by default, so I ran the above test after
disabling zswap shrinker. The results are as below.
config 0 1-1 1-2 1-3
perf_normalized 1.0000 0.0056 0.0185 0.0260
perf_stdev_ratio 0.0467 0.0348 0.1832 0.3387
zswpin 0 0 2506765 6049078
zswpout 0 0 2534357 6115426
zswpwb 0 0 0 0
pswpin 0 463694 472978 0
pswpout 0 686227 612149 0
The overall normalized performance of the different configs are very
similar to those of zswap shrinker enabled case. By adding the memory
pressure, the performance was dropped to 0.56% of the original one. By
enabling zswap without zswap shrinker, the performance was increased to
1.85% of the original one. By applying this patch on it, the performance
was further increased to 2.6% of the original one.
Even though zswap shrinker is disabled, 1-2 shows high numbers of pswpin
and pswpout because the incompressible pages are directly swapped out. In
the case of 1-3, it shows zero pswpin and pswpout since it saves
incompressible pages in the memory, and shows higher performance.
Note that the performance of 1-2 and 1-3 varies pretty much. Standard
deviation of the performance for 1-2 was about 18.32% of the performance,
while that for 1-3 was about 33.87%. Because zswap shrinker is disabled
and the memory pressure is induced by memory.high, the workload got
penalty_jiffies sleeps, and this resulted in the unstabilized performance.
Related Works
-------------
This is not an entirely new attempt. Nhat Pham and Takero Funaki tried
very similar approaches in October 2023[2] and April 2024[3],
respectively. The two approaches didn't get merged mainly due to the
metadata overhead concern. I described why I think that shouldn't be a
problem for this change, which is automatically disabled when writeback is
disabled, at the beginning of this changelog.
This patch is not particularly different from those, and actually built
upon those. I wrote this from scratch again, though. Hence adding
Suggested-by tags for them. Actually Nhat first suggested this to me
offlist.
Historically, writeback disabling was introduced partially as a way to
solve the LRU order issue. Yosry pointed out[4] this is still suboptimal
when the incompressible pages are cold, since the incompressible pages
will continuously be tried to be zswapped out, and burn CPU cycles for
compression attempts that will anyway fail. One imaginable solution for
the problem is reusing the swapped-out page and its struct page to store
in the zswap pool. But that's out of the scope of this patch.
[sj@kernel.org: mark zswap_stored_incompressible_pages as static]
Link: https://lkml.kernel.org/r/20250821161750.78192-1-sj@kernel.org
[sj@kernel.org: v5]
Link: https://lkml.kernel.org/r/20250822190817.49287-1-sj@kernel.org
[sj@kernel.org: cleanup incompressible pages handling code]
Link: https://lkml.kernel.org/r/20250828163913.57957-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20250819193404.46680-1-sj@kernel.org
Link: https://github.com/sjp38/eval_zswap/blob/master/run.sh [1]
Link: https://lore.kernel.org/20231017003519.1426574-3-nphamcs@gmail.com [2]
Link: https://lore.kernel.org/20240706022523.1104080-6-flintglass@gmail.com [3]
Link: https://lore.kernel.org/CAJD7tkZXS-UJVAFfvxJ0nNgTzWBiqepPYA4hEozi01_qktkitg@mail.gmail.com [4]
Signed-off-by: SeongJae Park <sj@kernel.org>
Suggested-by: Nhat Pham <nphamcs@gmail.com>
Suggested-by: Takero Funaki <flintglass@gmail.com>
Acked-by: Nhat Pham <nphamcs@gmail.com>
Acked-by: Chris Li <chrisl@kernel.org>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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adf085ff0d |
mm: remove redundant __GFP_NOWARN
Commit
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12e423ba4e |
mm: convert core mm to mm_flags_*() accessors
As part of the effort to move to mm->flags becoming a bitmap field, convert existing users to making use of the mm_flags_*() accessors which will, when the conversion is complete, be the only means of accessing mm_struct flags. This will result in the debug output being that of a bitmap output, which will result in a minor change here, but since this is for debug only, this should have no bearing. Otherwise, no functional changes intended. [akpm@linux-foundation.org: fix typo in comment]Link: https://lkml.kernel.org/r/1eb2266f4408798a55bda00cb04545a3203aa572.1755012943.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Barry Song <baohua@kernel.org> Cc: Ben Segall <bsegall@google.com> Cc: Borislav Betkov <bp@alien8.de> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dev Jain <dev.jain@arm.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Kees Cook <kees@kernel.org> Cc: Marc Rutland <mark.rutland@arm.com> Cc: Mariano Pache <npache@redhat.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Mateusz Guzik <mjguzik@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Namhyung kim <namhyung@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: xu xin <xu.xin16@zte.com.cn> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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2d8bd8049e |
mm: add persistent huge zero folio
Many places in the kernel need to zero out larger chunks, but the maximum segment that can be zeroed out at a time by ZERO_PAGE is limited by PAGE_SIZE. This is especially annoying in block devices and filesystems where multiple ZERO_PAGEs are attached to the bio in different bvecs. With multipage bvec support in block layer, it is much more efficient to send out larger zero pages as a part of single bvec. This concern was raised during the review of adding Large Block Size support to XFS[1][2]. Usually huge_zero_folio is allocated on demand, and it will be deallocated by the shrinker if there are no users of it left. At moment, huge_zero_folio infrastructure refcount is tied to the process lifetime that created it. This might not work for bio layer as the completions can be async and the process that created the huge_zero_folio might no longer be alive. And, one of the main points that came up during discussion is to have something bigger than zero page as a drop-in replacement. Add a config option PERSISTENT_HUGE_ZERO_FOLIO that will result in allocating the huge zero folio during early init and never free the memory by disabling the shrinker. This makes using the huge_zero_folio without having to pass any mm struct and does not tie the lifetime of the zero folio to anything, making it a drop-in replacement for ZERO_PAGE. If PERSISTENT_HUGE_ZERO_FOLIO config option is enabled, then mm_get_huge_zero_folio() will simply return the allocated page instead of dynamically allocating a new PMD page. Use this option carefully in resource constrained systems as it uses one full PMD sized page for zeroing purposes. [1] https://lore.kernel.org/linux-xfs/20231027051847.GA7885@lst.de/ [2] https://lore.kernel.org/linux-xfs/ZitIK5OnR7ZNY0IG@infradead.org/ Link: https://lkml.kernel.org/r/20250811084113.647267-4-kernel@pankajraghav.com Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Pankaj Raghav <p.raghav@samsung.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Co-developed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Christoph Hellwig <hch@lst.de> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Luis Chamberalin <mcgrof@kernel.org> Cc: Mariano Pache <npache@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Cc: Kiryl Shutsemau <kirill@shutemov.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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2843408ca9 |
mm: rename MMF_HUGE_ZERO_PAGE to MMF_HUGE_ZERO_FOLIO
As all the helper functions has been renamed from *_page to *_folio, rename the MM flag from MMF_HUGE_ZERO_PAGE to MMF_HUGE_ZERO_FOLIO. No functional changes. Link: https://lkml.kernel.org/r/20250811084113.647267-3-kernel@pankajraghav.com Signed-off-by: Pankaj Raghav <p.raghav@samsung.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Christoph Hellwig <hch@lst.de> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Luis Chamberalin <mcgrof@kernel.org> Cc: Mariano Pache <npache@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Kiryl Shutsemau <kirill@shutemov.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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b912586ba7 |
mm: rename huge_zero_page to huge_zero_folio
Patch series "add persistent huge zero folio support", v3. Many places in the kernel need to zero out larger chunks, but the maximum segment we can zero out at a time by ZERO_PAGE is limited by PAGE_SIZE. This concern was raised during the review of adding Large Block Size support to XFS[1][2]. This is especially annoying in block devices and filesystems where multiple ZERO_PAGEs are attached to the bio in different bvecs. With multipage bvec support in block layer, it is much more efficient to send out larger zero pages as a part of single bvec. Some examples of places in the kernel where this could be useful: - blkdev_issue_zero_pages() - iomap_dio_zero() - vmalloc.c:zero_iter() - rxperf_process_call() - fscrypt_zeroout_range_inline_crypt() - bch2_checksum_update() ... Usually huge_zero_folio is allocated on demand, and it will be deallocated by the shrinker if there are no users of it left. At the moment, huge_zero_folio infrastructure refcount is tied to the process lifetime that created it. This might not work for bio layer as the completions can be async and the process that created the huge_zero_folio might no longer be alive. And, one of the main point that came during discussion is to have something bigger than zero page as a drop-in replacement. Add a config option PERSISTENT_HUGE_ZERO_FOLIO that will always allocate the huge_zero_folio, and disable the shrinker so that huge_zero_folio is never freed. This makes using the huge_zero_folio without having to pass any mm struct and does not tie the lifetime of the zero folio to anything, making it a drop-in replacement for ZERO_PAGE. I have converted blkdev_issue_zero_pages() as an example as a part of this series. I also noticed close to 4% performance improvement just by replacing ZERO_PAGE with persistent huge_zero_folio. I will send patches to individual subsystems using the huge_zero_folio once this gets upstreamed. [1] https://lore.kernel.org/linux-xfs/20231027051847.GA7885@lst.de/ [2] https://lore.kernel.org/linux-xfs/ZitIK5OnR7ZNY0IG@infradead.org/ As the transition already happened from exposing huge_zero_page to huge_zero_folio, change the name of the shrinker and the other helper function to reflect that. No functional changes. Link: https://lkml.kernel.org/r/20250811084113.647267-1-kernel@pankajraghav.com Link: https://lkml.kernel.org/r/20250811084113.647267-2-kernel@pankajraghav.com Signed-off-by: Pankaj Raghav <p.raghav@samsung.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Christoph Hellwig <hch@lst.de> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Luis Chamberalin <mcgrof@kernel.org> Cc: Mariano Pache <npache@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Kiryl Shutsemau <kirill@shutemov.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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4c89792ea0 |
mm: rename vm_ops->find_special_page() to vm_ops->find_normal_page()
... and hide it behind a kconfig option. There is really no need for any
!xen code to perform this check.
The naming is a bit off: we want to find the "normal" page when a PTE was
marked "special". So it's really not "finding a special" page.
Improve the documentation, and add a comment in the code where XEN ends up
performing the pte_mkspecial() through a hypercall. More details can be
found in commit
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2db308160b |
mm: introduce and use vm_normal_page_pud()
Let's introduce vm_normal_page_pud(), which ends up being fairly simple because of our new common helpers and there not being a PUD-sized zero folio. Use vm_normal_page_pud() in folio_walk_start() to resolve a TODO, structuring the code like the other (pmd/pte) cases. Defer introducing vm_normal_folio_pud() until really used. Note that we can so far get PUDs with hugetlb, daxfs and PFNMAP entries. Link: https://lkml.kernel.org/r/20250811112631.759341-11-david@redhat.com Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Juegren Gross <jgross@suse.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mariano Pache <npache@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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af38538801 |
mm/memory: factor out common code from vm_normal_page_*()
Let's reduce the code duplication and factor out the non-pte/pmd related magic into __vm_normal_page(). To keep it simpler, check the pfn against both zero folios, which shouldn't really make a difference. It's a good question if we can even hit the !CONFIG_ARCH_HAS_PTE_SPECIAL scenario in the PMD case in practice: but doesn't really matter, as it's now all unified in vm_normal_page_pfn(). Add kerneldoc for all involved functions. Note that, as a side product, we now: * Support the find_special_page special thingy also for PMD * Don't check for is_huge_zero_pfn() anymore if we have CONFIG_ARCH_HAS_PTE_SPECIAL and the PMD is not special. The VM_WARN_ON_ONCE would catch any abuse No functional change intended. Link: https://lkml.kernel.org/r/20250811112631.759341-10-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Juegren Gross <jgross@suse.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mariano Pache <npache@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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ec63a44011 |
mm/memory: convert print_bad_pte() to print_bad_page_map()
print_bad_pte() looks like something that should actually be a WARN or similar, but historically it apparently has proven to be useful to detect corruption of page tables even on production systems -- report the issue and keep the system running to make it easier to actually detect what is going wrong (e.g., multiple such messages might shed a light). As we want to unify vm_normal_page_*() handling for PTE/PMD/PUD, we'll have to take care of print_bad_pte() as well. Let's prepare for using print_bad_pte() also for non-PTEs by adjusting the implementation and renaming the function to print_bad_page_map(). Provide print_bad_pte() as a simple wrapper. Document the implicit locking requirements for the page table re-walk. To make the function a bit more readable, factor out the ratelimit check into is_bad_page_map_ratelimited() and place the printing of page table content into __print_bad_page_map_pgtable(). We'll now dump information from each level in a single line, and just stop the table walk once we hit something that is not a present page table. The report will now look something like (dumping pgd to pmd values): [ 77.943408] BUG: Bad page map in process XXX pte:80000001233f5867 [ 77.944077] addr:00007fd84bb1c000 vm_flags:08100071 anon_vma: ... [ 77.945186] pgd:10a89f067 p4d:10a89f067 pud:10e5a2067 pmd:105327067 Not using pgdp_get(), because that does not work properly on some arm configs where pgd_t is an array. Note that we are dumping all levels even when levels are folded for simplicity. [david@redhat.com: drop warning] Link: https://lkml.kernel.org/r/923b279c-de33-44dd-a923-2959afad8626@redhat.com Link: https://lkml.kernel.org/r/20250811112631.759341-9-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Juegren Gross <jgross@suse.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mariano Pache <npache@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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b22cc9a9c7 |
mm/rmap: convert "enum rmap_level" to "enum pgtable_level"
Let's factor it out, and convert all checks for unsupported levels to BUILD_BUG(). The code is written in a way such that force-inlining will optimize out the levels. [nathan@kernel.org: always inline __folio_rmap_sanity_checks()] Link: https://lkml.kernel.org/r/20250814-rmap-fix-build_bug-conversion-v1-1-fb7b10a0b362@kernel.org Link: https://lkml.kernel.org/r/20250811112631.759341-8-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Juegren Gross <jgross@suse.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mariano Pache <npache@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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d82d09e482 |
mm/huge_memory: mark PMD mappings of the huge zero folio special
The huge zero folio is refcounted (+mapcounted -- is that a word?) differently than "normal" folios, similarly (but different) to the ordinary shared zeropage. For this reason, we special-case these pages in vm_normal_page*/vm_normal_folio*, and only allow selected callers to still use them (e.g., GUP can still take a reference on them). vm_normal_page_pmd() already filters out the huge zero folio, to indicate it a special (return NULL). However, so far we are not making use of pmd_special() on architectures that support it (CONFIG_ARCH_HAS_PTE_SPECIAL), like we would with the ordinary shared zeropage. Let's mark PMD mappings of the huge zero folio similarly as special, so we can avoid the manual check for the huge zero folio with CONFIG_ARCH_HAS_PTE_SPECIAL next, and only perform the check on !CONFIG_ARCH_HAS_PTE_SPECIAL. In copy_huge_pmd(), where we have a manual pmd_special() check to handle PFNMAP, we have to manually rule out the huge zero folio. That code needs a serious cleanup, but that's something for another day. While at it, update the doc regarding the shared zero folios. No functional change intended: vm_normal_page_pmd() still returns NULL when it encounters the huge zero folio. Link: https://lkml.kernel.org/r/20250811112631.759341-6-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Juegren Gross <jgross@suse.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mariano Pache <npache@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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5528ef06da |
mm/huge_memory: support huge zero folio in vmf_insert_folio_pmd()
Just like we do for vmf_insert_page_mkwrite() -> ... -> insert_page_into_pte_locked() with the shared zeropage, support the huge zero folio in vmf_insert_folio_pmd(). When (un)mapping the huge zero folio in page tables, we neither adjust the refcount nor the mapcount, just like for the shared zeropage. For now, the huge zero folio is not marked as special yet, although vm_normal_page_pmd() really wants to treat it as special. We'll change that next. Link: https://lkml.kernel.org/r/20250811112631.759341-4-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Juegren Gross <jgross@suse.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mariano Pache <npache@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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77e493280e |
mm/huge_memory: move more common code into insert_pud()
Let's clean it all further up. No functional change intended. Link: https://lkml.kernel.org/r/20250811112631.759341-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Juegren Gross <jgross@suse.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mariano Pache <npache@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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b7298e418e |
mm/huge_memory: move more common code into insert_pmd()
Patch series "mm: vm_normal_page*() improvements", v3. Cleanup and unify vm_normal_page_*() handling, also marking the huge zerofolio as special in the PMD. Add+use vm_normal_page_pud() and cleanup that XEN vm_ops->find_special_page thingy. There are plans of using vm_normal_page_*() more widely soon. This patch (of 11): Let's clean it all further up. No functional change intended. Link: https://lkml.kernel.org/r/20250811112631.759341-1-david@redhat.com Link: https://lkml.kernel.org/r/20250811112631.759341-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Juegren Gross <jgross@suse.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mariano Pache <npache@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Cc: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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fb49a4425c |
treewide: remove MIGRATEPAGE_SUCCESS
At this point MIGRATEPAGE_SUCCESS is misnamed for all folio users, and now that we remove MIGRATEPAGE_UNMAP, it's really the only "success" return value that the code uses and expects. Let's just get rid of MIGRATEPAGE_SUCCESS completely and just use "0" for success. Link: https://lkml.kernel.org/r/20250811143949.1117439-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> [mm] Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com> [jfs] Acked-by: David Sterba <dsterba@suse.com> [btrfs] Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Byungchul Park <byungchul@sk.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Chris Mason <clm@fb.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Kleikamp <shaggy@kernel.org> Cc: Eugenio Pé rez <eperezma@redhat.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Wang <jasowang@redhat.com> Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Lance Yang <lance.yang@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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95c2908f1a |
mm/migrate: remove MIGRATEPAGE_UNMAP
migrate_folio_unmap() is the only user of MIGRATEPAGE_UNMAP. We want to remove MIGRATEPAGE_* completely. It's rather weird to have a generic MIGRATEPAGE_UNMAP, documented to be returned from address-space callbacks, when it's only used for an internal helper. Let's start by having only a single "success" return value for migrate_folio_unmap() -- 0 -- by moving the "folio was already freed" check into the single caller. There is a remaining comment for PG_isolated, which we renamed to PG_movable_ops_isolated recently and forgot to update. While we might still run into that case with zsmalloc, it's something we want to get rid of soon. So let's just focus that optimization on real folios only for now by excluding movable_ops pages. Note that concurrent freeing can happen at any time and this "already freed" check is not relevant for correctness. [david@redhat.com: no need to pass "reason" to migrate_folio_unmap(), per Lance] Link: https://lkml.kernel.org/r/3bb725f8-28d7-4aa2-b75f-af40d5cab280@redhat.com Link: https://lkml.kernel.org/r/20250811143949.1117439-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Byungchul Park <byungchul@sk.com> Cc: Chris Mason <clm@fb.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Kleikamp <shaggy@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: Eugenio Pé rez <eperezma@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Wang <jasowang@redhat.com> Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Dave Kleikamp <dave.kleikamp@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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1f2052755c |
mm/mincore: use a helper for checking the swap cache
Introduce a mincore_swap helper for checking swap entries. Move all swap related logic and sanity debug check into it, and separate them from page cache checking. The performance is better after this commit. mincore_page is never called on a swap cache space now, so the logic can be simpler. The sanity check also covers more potential cases now, previously the WARN_ON only catches potentially corrupted page table, now if shmem contains a swap entry with !CONFIG_SWAP, a WARN will be triggered. This changes the mincore value when the WARN is triggered, but this shouldn't matter. The WARN_ON means the data is already corrupted or something is very wrong, so it really should not happen. Before this series: mincore on a swaped out 16G anon mmap range: Took 488220 us mincore on 16G shmem mmap range: Took 530272 us. After this commit: mincore on a swaped out 16G anon mmap range: Took 446763 us mincore on 16G shmem mmap range: Took 460496 us. About ~10% faster. Link: https://lkml.kernel.org/r/20250811172018.48901-3-ryncsn@gmail.com Signed-off-by: Kairui Song <kasong@tencent.com> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: Chris Li <chrisl@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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27763edac9 |
mm/mincore, swap: consolidate swap cache checking for mincore
Patch series "mm/mincore: minor clean up for swap cache checking". This series cleans up a swap cache helper only used by mincore, move it back into mincore code. Also separate the swap cache related logics out of shmem / page cache logics in mincore. With this series we have less lines of code and better performance. Before this series: mincore on a swaped out 16G anon mmap range: Took 488220 us mincore on 16G shmem mmap range: Took 530272 us. After this series: mincore on a swaped out 16G anon mmap range: Took 446763 us mincore on 16G shmem mmap range: Took 460496 us. About ~10% faster. This patch (of 2): The filemap_get_incore_folio (previously find_get_incore_page) helper was introduced by commit |
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3e86861d00 |
mm/kasan/init.c: remove unnecessary pointer variables
Simplify the code to enhance readability and maintain a consistent coding style. Link: https://lkml.kernel.org/r/20250811034257.154862-1-zhao.xichao@vivo.com Signed-off-by: Xichao Zhao <zhao.xichao@vivo.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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63f39737d1 |
mm/damon/vaddr: support stat-purpose DAMOS filters
This patch extends DAMOS_STAT handling of the DAMON operations sets for virtual address spaces for ops-level DAMOS filters. It leverages the walk_page_range to walk the page table and gets the folio from page table. The last folio scanned is stored in damos->last_applied to prevent double counting. Link: https://lkml.kernel.org/r/264a4b5ea202fd73c01b349c9694d8bf9978c441.1754135312.git.pyyjason@gmail.com Signed-off-by: Yueyang Pan <pyyjason@gmail.com> Reviewed-by: SeongJae Park <sj@kernel.org> Cc: Usama Arif <usamaarif642@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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408b299a62 |
mm/damon/paddr: move filters existence check function to ops-common
Patch series "mm/damon/vaddr: support stat-purpose DAMOS filters", v4.
Extend DAMOS_STAT handling of the DAMON operations sets for virtual
address spaces for ops-level DAMOS filters.
Functionality Test
==================
I wrote a small test program which allocates 10GB of DRAM, use
madvise(MADV_HUGEPAGE) to convert the base pages to 2MB huge pages Then my
program does the following things in order:
1. Write sequentially to the whole 10GB region
2. Read the first 5GB region sequentially for 10 times
3. Sleep 5s
4. Read the second 5GB region sequentially for 10 times
With a proper damon setting, we are expected to see df-passed to be 10GB
and hot region move around with the read
$ # Start DAMON
$ sudo ./damo/damo start "./my_test/test" --monitoring_intervals 100ms\
1s 2s
$ # Show DAMON-generated access pattern snapshot
$ sudo ./damo/damo report access --snapshot_damos_filter allow \
hugepage_size 2MiB 2MiB
heatmap:
# min/max temperatures: -600,000,000, 100,001,000, column size: 137.352 MiB
intervals: sample 100 ms aggr 1 s (max access hz 10)
# damos filters (df): reject none hugepage_size [2.000 MiB, 2.000 MiB]
df-pass:
# min/max temperatures: -400,000,000, 100,001,000, column size: 128.031 MiB
0 addr 85.373 TiB size 745.555 MiB access 0 hz age 6 s df-passed 0 B
1 addr 127.608 TiB size 877.664 MiB access 3.000 hz age 0 ns df-passed 878.000 MiB
2 addr 127.609 TiB size 219.418 MiB access 2.000 hz age 0 ns df-passed 220.000 MiB
3 addr 127.609 TiB size 316.613 MiB access 1.000 hz age 1 s df-passed 316.000 MiB
4 addr 127.609 TiB size 474.922 MiB access 1.000 hz age 1 s df-passed 476.000 MiB
5 addr 127.610 TiB size 407.188 MiB access 1.000 hz age 0 ns df-passed 406.000 MiB
6 addr 127.610 TiB size 610.781 MiB access 1.000 hz age 0 ns df-passed 612.000 MiB
7 addr 127.611 TiB size 697.309 MiB access 0 hz age 0 ns df-passed 696.000 MiB
8 addr 127.611 TiB size 77.480 MiB access 1.000 hz age 0 ns df-passed 78.000 MiB
9 addr 127.611 TiB size 573.102 MiB access 1.000 hz age 0 ns df-passed 574.000 MiB
10 addr 127.612 TiB size 245.617 MiB access 2.000 hz age 0 ns df-passed 246.000 MiB
11 addr 127.612 TiB size 295.102 MiB access 1.000 hz age 1 s df-passed 294.000 MiB
12 addr 127.612 TiB size 295.105 MiB access 1.000 hz age 1 s df-passed 296.000 MiB
13 addr 127.613 TiB size 67.172 MiB access 1.000 hz age 1 s df-passed 66.000 MiB
14 addr 127.613 TiB size 604.570 MiB access 0 hz age 1 s df-passed 606.000 MiB
15 addr 127.613 TiB size 389.578 MiB access 0 hz age 4 s df-passed 388.000 MiB
16 addr 127.614 TiB size 259.719 MiB access 0 hz age 4 s df-passed 260.000 MiB
17 addr 127.614 TiB size 817.941 MiB access 0 hz age 4 s df-passed 818.000 MiB
18 addr 127.615 TiB size 204.488 MiB access 0 hz age 4 s df-passed 204.000 MiB
19 addr 127.615 TiB size 730.902 MiB access 0 hz age 4 s df-passed 732.000 MiB
20 addr 127.616 TiB size 182.727 MiB access 0 hz age 4 s df-passed 182.000 MiB
21 addr 127.616 TiB size 926.824 MiB access 0 hz age 2 s df-passed 928.000 MiB
22 addr 127.617 TiB size 102.984 MiB access 0 hz age 2 s df-passed 102.000 MiB
23 addr 127.617 TiB size 86.527 MiB access 0 hz age 2 s df-passed 86.000 MiB
24 addr 127.617 TiB size 778.777 MiB access 0 hz age 2 s df-passed 776.000 MiB
25 addr 127.999 TiB size 132.000 KiB access 0 hz age 6 s df-passed 0 B
memory bw estimate: 6.524 GiB per second df-passed: 6.527 GiB per second
total size: 10.731 GiB df-passed 10.000 GiB
record DAMON intervals: sample 100 ms, aggr 1 s
$ # Show DAMON-generated access pattern snapshot again
$ sudo ./damo/damo report access --snapshot_damos_filter allow \
hugepage_size 2MiB 2MiB
heatmap:
# min/max temperatures: -1,100,000,000, 2,000, column size: 137.352 MiB
intervals: sample 100 ms aggr 1 s (max access hz 10)
# damos filters (df): reject none hugepage_size [2.000 MiB, 2.000 MiB]
df-pass:
# min/max temperatures: -900,000,000, 2,000, column size: 128.031 MiB
0 addr 85.373 TiB size 745.555 MiB access 0 hz age 11 s df-passed 0 B
1 addr 127.608 TiB size 579.715 MiB access 2.000 hz age 0 ns df-passed 580.000 MiB
2 addr 127.608 TiB size 144.930 MiB access 2.000 hz age 0 ns df-passed 146.000 MiB
3 addr 127.608 TiB size 452.453 MiB access 2.000 hz age 0 ns df-passed 452.000 MiB
4 addr 127.609 TiB size 113.117 MiB access 1.000 hz age 0 ns df-passed 114.000 MiB
5 addr 127.609 TiB size 182.367 MiB access 2.000 hz age 0 ns df-passed 182.000 MiB
6 addr 127.609 TiB size 182.371 MiB access 2.000 hz age 0 ns df-passed 182.000 MiB
7 addr 127.609 TiB size 350.488 MiB access 1.000 hz age 0 ns df-passed 350.000 MiB
8 addr 127.610 TiB size 525.738 MiB access 1.000 hz age 0 ns df-passed 526.000 MiB
9 addr 127.610 TiB size 401.352 MiB access 1.000 hz age 0 ns df-passed 402.000 MiB
10 addr 127.611 TiB size 100.340 MiB access 1.000 hz age 0 ns df-passed 100.000 MiB
11 addr 127.611 TiB size 19.523 MiB access 0 hz age 0 ns df-passed 20.000 MiB
12 addr 127.611 TiB size 175.727 MiB access 0 hz age 0 ns df-passed 176.000 MiB
13 addr 127.611 TiB size 106.629 MiB access 0 hz age 0 ns df-passed 106.000 MiB
14 addr 127.611 TiB size 959.676 MiB access 0 hz age 0 ns df-passed 960.000 MiB
15 addr 127.612 TiB size 424.469 MiB access 1.000 hz age 0 ns df-passed 424.000 MiB
16 addr 127.612 TiB size 424.469 MiB access 1.000 hz age 0 ns df-passed 424.000 MiB
17 addr 127.613 TiB size 201.648 MiB access 0 hz age 6 s df-passed 202.000 MiB
18 addr 127.613 TiB size 806.609 MiB access 0 hz age 6 s df-passed 806.000 MiB
19 addr 127.614 TiB size 862.125 MiB access 0 hz age 9 s df-passed 862.000 MiB
20 addr 127.614 TiB size 215.535 MiB access 0 hz age 9 s df-passed 216.000 MiB
21 addr 127.615 TiB size 104.500 MiB access 0 hz age 9 s df-passed 104.000 MiB
22 addr 127.615 TiB size 940.523 MiB access 0 hz age 9 s df-passed 942.000 MiB
23 addr 127.616 TiB size 640.281 MiB access 0 hz age 7 s df-passed 640.000 MiB
24 addr 127.616 TiB size 426.855 MiB access 0 hz age 7 s df-passed 426.000 MiB
25 addr 127.617 TiB size 90.105 MiB access 0 hz age 7 s df-passed 90.000 MiB
26 addr 127.617 TiB size 810.965 MiB access 0 hz age 7 s df-passed 808.000 MiB
27 addr 127.999 TiB size 132.000 KiB access 0 hz age 11 s df-passed 0 B
memory bw estimate: 5.297 GiB per second df-passed: 5.297 GiB per second
total size: 10.731 GiB df-passed 10.000 GiB
record DAMON intervals: sample 100 ms, aggr 1 s
As you can see the total df-passed region is 10GiB and the hot region
moves as the seq read keeps going
This patch (of 2):
This patch moves damon_pa_scheme_has_filter to ops-common. renaming to
damos_ops_has_filter. Doing so allows us to reuse its logic in the vaddr
version of DAMOS_STAT.
Link: https://lkml.kernel.org/r/cover.1754135312.git.pyyjason@gmail.com
Link: https://lkml.kernel.org/r/cbe01740f7ac5ac7c9fd1ca367d297c3d7f2a69d.1754135312.git.pyyjason@gmail.com
Signed-off-by: Yueyang Pan <pyyjason@gmail.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: Usama Arif <usamaarif642@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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dc32c8d487 |
mm/damon/core: skip needless update of damon_attrs in damon_commit_ctx()
Currently, damon_commit_ctx() always calls damon_set_attrs() even if the
attributes have not been changed. This can be problematic when the DAMON
state is committed relatively frequently because damon_set_attrs() resets
ctx->next_{aggregation,ops_update}_sis, causing aggregation and ops update
operations to be needlessly delayed.
This patch avoids this by only calling damon_set_attrs() in
damon_commit_ctx when the attributes have been changed.
[akpm@linux-foundation.org:
Link: https://lkml.kernel.org/r/20250807001924.76275-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20250806234254.10572-1-bijan311@gmail.com
Signed-off-by: Bijan Tabatabai <bijantabatab@micron.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: Bijan Tabatabai <bijan311@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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878d9e8ceb |
mm/rmap: do __folio_mod_stat() in __folio_add_rmap()
It is required to modify folio statistic after rmap changes, so it looks reasonable to do it in __folio_add_rmap(), which is the current behavior of __folio_remove_rmap() and folio_add_new_anon_rmap(). Call __folio_mod_stat() in __folio_add_rmap(), so that rmap adjustment family shares the same pattern. Link: https://lkml.kernel.org/r/20250804064106.21269-1-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Rik van Riel <riel@surriel.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Harry Yoo <harry.yoo@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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1097a3d456 |
mm/nommu: convert kobjsize() to folios
Simple folio conversion to remove a user of PageSlab() and PageCompound(). Link: https://lkml.kernel.org/r/20250804145117.3857308-1-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: SeongJae Park <sj@kernel.org> Cc: Jann Horn <jannh@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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2cd8231796 |
mm/slub: allow to set node and align in k[v]realloc
Reimplement k[v]realloc_node() to be able to set node and alignment should a user need to do so. In order to do that while retaining the maximal backward compatibility, add k[v]realloc_node_align() functions and redefine the rest of API using these new ones. While doing that, we also keep the number of _noprof variants to a minimum, which implies some changes to the existing users of older _noprof functions, that basically being bcachefs. With that change we also provide the ability for the Rust part of the kernel to set node and alignment in its K[v]xxx [re]allocations. Link: https://lkml.kernel.org/r/20250806124147.1724658-1-vitaly.wool@konsulko.se Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.se> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Jann Horn <jannh@google.com> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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4c5d336588 |
mm/vmalloc: allow to set node and align in vrealloc
Patch series "support large align and nid in Rust allocators", v15. The series provides the ability for Rust allocators to set NUMA node and large alignment. This patch (of 4): Reimplement vrealloc() to be able to set node and alignment should a user need to do so. Rename the function to vrealloc_node_align() to better match what it actually does now and introduce macros for vrealloc() and friends for backward compatibility. With that change we also provide the ability for the Rust part of the kernel to set node and alignment in its allocations. Link: https://lkml.kernel.org/r/20250806124034.1724515-1-vitaly.wool@konsulko.se Link: https://lkml.kernel.org/r/20250806124108.1724561-1-vitaly.wool@konsulko.se Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.se> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Jann Horn <jannh@google.com> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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9a42aed484 |
mm, swap: prefer nonfull over free clusters
We prefer a free cluster over a nonfull cluster whenever a CPU local cluster is drained to respect the SSD discard behavior [1]. It's not a best practice for non-discarding devices. And this is causing a higher fragmentation rate. So for a non-discarding device, prefer nonfull over free clusters. This reduces the fragmentation issue by a lot. Testing with make -j96, defconfig, using 64k mTHP, 8G ZRAM: Before: sys time: 6176.34s 64kB/swpout: 1659757 64kB/swpout_fallback: 139503 After: sys time: 6194.11s 64kB/swpout: 1689470 64kB/swpout_fallback: 56147 Testing with make -j96, defconfig, using 64k mTHP, 10G ZRAM: After: sys time: 5531.49s 64kB/swpout: 1791142 64kB/swpout_fallback: 17676 After: sys time: 5587.53s 64kB/swpout: 1811598 64kB/swpout_fallback: 0 Performance is basically unchanged, and the large allocation failure rate is lower. Enabling all mTHP sizes showed a more significant result. Using the same test setup with 10G ZRAM and enabling all mTHP sizes: 128kB swap failure rate: Before: swpout:451599 swpout_fallback:54525 After: swpout:502710 swpout_fallback:870 256kB swap failure rate: Before: swpout:63652 swpout_fallback:2708 After: swpout:65913 swpout_fallback:20 512kB swap failure rate: Before: swpout:11663 swpout_fallback:1767 After: swpout:14480 swpout_fallback:6 2M swap failure rate: Before: swpout:24 swpout_fallback:1442 After: swpout:1329 swpout_fallback:7 The success rate of large allocations is much higher. Link: https://lore.kernel.org/linux-mm/87v8242vng.fsf@yhuang6-desk2.ccr.corp.intel.com/ [1] Link: https://lkml.kernel.org/r/20250806161748.76651-4-ryncsn@gmail.com Signed-off-by: Kairui Song <kasong@tencent.com> Acked-by: Chris Li <chrisl@kernel.org> Reviewed-by: Nhat Pham <nphamcs@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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913fff3145 |
mm, swap: remove fragment clusters counter
It was used for calculating the iteration number when the swap allocator wants to scan the whole fragment list. Now the allocator only scans one fragment cluster at a time, so no one uses this counter anymore. Remove it as a cleanup; the performance change is marginal: Build linux kernel using 10G ZRAM, make -j96, defconfig with 2G cgroup memory limit, on top of tmpfs, 64kB mTHP enabled: Before: sys time: 6278.45s After: sys time: 6176.34s Change to 8G ZRAM: Before: sys time: 5572.85s After: sys time: 5531.49s Link: https://lkml.kernel.org/r/20250806161748.76651-3-ryncsn@gmail.com Signed-off-by: Kairui Song <kasong@tencent.com> Reviewed-by: Nhat Pham <nphamcs@gmail.com> Acked-by: Chris Li <chrisl@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |