<feed xmlns='http://www.w3.org/2005/Atom'>
<title>lwn.git/include/linux/vmstat.h, branch v6.11-rc3</title>
<subtitle>Linux kernel documentation tree maintained by Jonathan Corbet</subtitle>
<id>http://mirrors.hust.edu.cn/git/lwn.git/atom?h=v6.11-rc3</id>
<link rel='self' href='http://mirrors.hust.edu.cn/git/lwn.git/atom?h=v6.11-rc3'/>
<link rel='alternate' type='text/html' href='http://mirrors.hust.edu.cn/git/lwn.git/'/>
<updated>2024-07-24T18:59:29+00:00</updated>
<entry>
<title>sysctl: treewide: constify the ctl_table argument of proc_handlers</title>
<updated>2024-07-24T18:59:29+00:00</updated>
<author>
<name>Joel Granados</name>
<email>j.granados@samsung.com</email>
</author>
<published>2024-07-24T18:59:29+00:00</published>
<link rel='alternate' type='text/html' href='http://mirrors.hust.edu.cn/git/lwn.git/commit/?id=78eb4ea25cd5fdbdae7eb9fdf87b99195ff67508'/>
<id>urn:sha1:78eb4ea25cd5fdbdae7eb9fdf87b99195ff67508</id>
<content type='text'>
const qualify the struct ctl_table argument in the proc_handler function
signatures. This is a prerequisite to moving the static ctl_table
structs into .rodata data which will ensure that proc_handler function
pointers cannot be modified.

This patch has been generated by the following coccinelle script:

```
  virtual patch

  @r1@
  identifier ctl, write, buffer, lenp, ppos;
  identifier func !~ "appldata_(timer|interval)_handler|sched_(rt|rr)_handler|rds_tcp_skbuf_handler|proc_sctp_do_(hmac_alg|rto_min|rto_max|udp_port|alpha_beta|auth|probe_interval)";
  @@

  int func(
  - struct ctl_table *ctl
  + const struct ctl_table *ctl
    ,int write, void *buffer, size_t *lenp, loff_t *ppos);

  @r2@
  identifier func, ctl, write, buffer, lenp, ppos;
  @@

  int func(
  - struct ctl_table *ctl
  + const struct ctl_table *ctl
    ,int write, void *buffer, size_t *lenp, loff_t *ppos)
  { ... }

  @r3@
  identifier func;
  @@

  int func(
  - struct ctl_table *
  + const struct ctl_table *
    ,int , void *, size_t *, loff_t *);

  @r4@
  identifier func, ctl;
  @@

  int func(
  - struct ctl_table *ctl
  + const struct ctl_table *ctl
    ,int , void *, size_t *, loff_t *);

  @r5@
  identifier func, write, buffer, lenp, ppos;
  @@

  int func(
  - struct ctl_table *
  + const struct ctl_table *
    ,int write, void *buffer, size_t *lenp, loff_t *ppos);

```

* Code formatting was adjusted in xfs_sysctl.c to comply with code
  conventions. The xfs_stats_clear_proc_handler,
  xfs_panic_mask_proc_handler and xfs_deprecated_dointvec_minmax where
  adjusted.

* The ctl_table argument in proc_watchdog_common was const qualified.
  This is called from a proc_handler itself and is calling back into
  another proc_handler, making it necessary to change it as part of the
  proc_handler migration.

Co-developed-by: Thomas Weißschuh &lt;linux@weissschuh.net&gt;
Signed-off-by: Thomas Weißschuh &lt;linux@weissschuh.net&gt;
Co-developed-by: Joel Granados &lt;j.granados@samsung.com&gt;
Signed-off-by: Joel Granados &lt;j.granados@samsung.com&gt;
</content>
</entry>
<entry>
<title>mm: report per-page metadata information</title>
<updated>2024-07-04T02:30:09+00:00</updated>
<author>
<name>Sourav Panda</name>
<email>souravpanda@google.com</email>
</author>
<published>2024-06-05T22:27:51+00:00</published>
<link rel='alternate' type='text/html' href='http://mirrors.hust.edu.cn/git/lwn.git/commit/?id=15995a35247442aefa0ffe36a6dad51cb46b0918'/>
<id>urn:sha1:15995a35247442aefa0ffe36a6dad51cb46b0918</id>
<content type='text'>
Today, we do not have any observability of per-page metadata and how much
it takes away from the machine capacity.  Thus, we want to describe the
amount of memory that is going towards per-page metadata, which can vary
depending on build configuration, machine architecture, and system use.

This patch adds 2 fields to /proc/vmstat that can used as shown below:

Accounting per-page metadata allocated by boot-allocator:
	/proc/vmstat:nr_memmap_boot * PAGE_SIZE

Accounting per-page metadata allocated by buddy-allocator:
	/proc/vmstat:nr_memmap * PAGE_SIZE

Accounting total Perpage metadata allocated on the machine:
	(/proc/vmstat:nr_memmap_boot +
	 /proc/vmstat:nr_memmap) * PAGE_SIZE

Utility for userspace:

Observability: Describe the amount of memory overhead that is going to
per-page metadata on the system at any given time since this overhead is
not currently observable.

Debugging: Tracking the changes or absolute value in struct pages can help
detect anomalies as they can be correlated with other metrics in the
machine (e.g., memtotal, number of huge pages, etc).

page_ext overheads: Some kernel features such as page_owner
page_table_check that use page_ext can be optionally enabled via kernel
parameters.  Having the total per-page metadata information helps users
precisely measure impact.  Furthermore, page-metadata metrics will reflect
the amount of struct pages reliquished (or overhead reduced) when
hugetlbfs pages are reserved which will vary depending on whether hugetlb
vmemmap optimization is enabled or not.

For background and results see:
lore.kernel.org/all/20240220214558.3377482-1-souravpanda@google.com

Link: https://lkml.kernel.org/r/20240605222751.1406125-1-souravpanda@google.com
Signed-off-by: Sourav Panda &lt;souravpanda@google.com&gt;
Acked-by: David Rientjes &lt;rientjes@google.com&gt;
Reviewed-by: Pasha Tatashin &lt;pasha.tatashin@soleen.com&gt;
Cc: Alexey Dobriyan &lt;adobriyan@gmail.com&gt;
Cc: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Cc: Chen Linxuan &lt;chenlinxuan@uniontech.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Ivan Babrou &lt;ivan@cloudflare.com&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Jonathan Corbet &lt;corbet@lwn.net&gt;
Cc: Kefeng Wang &lt;wangkefeng.wang@huawei.com&gt;
Cc: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Cc: Liam R. Howlett &lt;Liam.Howlett@oracle.com&gt;
Cc: Mike Kravetz &lt;mike.kravetz@oracle.com&gt;
Cc: Mike Rapoport (IBM) &lt;rppt@kernel.org&gt;
Cc: Muchun Song &lt;muchun.song@linux.dev&gt;
Cc: "Rafael J. Wysocki" &lt;rafael@kernel.org&gt;
Cc: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Cc: Shakeel Butt &lt;shakeelb@google.com&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Cc: Tomas Mudrunka &lt;tomas.mudrunka@gmail.com&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: Wei Xu &lt;weixugc@google.com&gt;
Cc: Yang Yang &lt;yang.yang29@zte.com.cn&gt;
Cc: Yosry Ahmed &lt;yosryahmed@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>mm: page_alloc: consolidate free page accounting</title>
<updated>2024-04-26T03:56:04+00:00</updated>
<author>
<name>Johannes Weiner</name>
<email>hannes@cmpxchg.org</email>
</author>
<published>2024-03-20T18:02:15+00:00</published>
<link rel='alternate' type='text/html' href='http://mirrors.hust.edu.cn/git/lwn.git/commit/?id=e0932b6c1f942fa747258e152cdce0d0b2b5be5c'/>
<id>urn:sha1:e0932b6c1f942fa747258e152cdce0d0b2b5be5c</id>
<content type='text'>
Free page accounting currently happens a bit too high up the call stack,
where it has to deal with guard pages, compaction capturing, block
stealing and even page isolation.  This is subtle and fragile, and makes
it difficult to hack on the code.

Now that type violations on the freelists have been fixed, push the
accounting down to where pages enter and leave the freelist.

[hannes@cmpxchg.org: undo unrelated drive-by line wrap]
  Link: https://lkml.kernel.org/r/20240327185736.GA7597@cmpxchg.org
[hannes@cmpxchg.org: remove unused page parameter from account_freepages()]
  Link: https://lkml.kernel.org/r/20240327185831.GB7597@cmpxchg.org
[baolin.wang@linux.alibaba.com: fix free page accounting]
  Link: https://lkml.kernel.org/r/a2a48baca69f103aa431fd201f8a06e3b95e203d.1712648441.git.baolin.wang@linux.alibaba.com
[andriy.shevchenko@linux.intel.com: avoid defining unused function]
  Link: https://lkml.kernel.org/r/20240423161506.2637177-1-andriy.shevchenko@linux.intel.com
Link: https://lkml.kernel.org/r/20240320180429.678181-11-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Signed-off-by: Baolin Wang &lt;baolin.wang@linux.alibaba.com&gt;
Reviewed-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Tested-by: Baolin Wang &lt;baolin.wang@linux.alibaba.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: "Huang, Ying" &lt;ying.huang@intel.com&gt;
Cc: Mel Gorman &lt;mgorman@techsingularity.net&gt;
Cc: Zi Yan &lt;ziy@nvidia.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>mm/memcontrol: remove __mod_lruvec_page_state()</title>
<updated>2024-01-05T18:17:47+00:00</updated>
<author>
<name>Matthew Wilcox (Oracle)</name>
<email>willy@infradead.org</email>
</author>
<published>2023-12-28T08:57:48+00:00</published>
<link rel='alternate' type='text/html' href='http://mirrors.hust.edu.cn/git/lwn.git/commit/?id=c701123bd68bf1cc3bc167b4f597cb1f4995c39c'/>
<id>urn:sha1:c701123bd68bf1cc3bc167b4f597cb1f4995c39c</id>
<content type='text'>
There are no more callers of __mod_lruvec_page_state(), so convert the
implementation to __lruvec_stat_mod_folio(), removing two calls to
compound_head() (one explicit, one hidden inside page_memcg()).

Link: https://lkml.kernel.org/r/20231228085748.1083901-7-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Reviewed-by: Zi Yan &lt;ziy@nvidia.com&gt;
Acked-by: Shakeel Butt &lt;shakeelb@google.com&gt;
Reviewed-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: Hyeonggon Yoo &lt;42.hyeyoo@gmail.com&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>mm: remove inc/dec lruvec page state functions</title>
<updated>2024-01-05T18:17:45+00:00</updated>
<author>
<name>Matthew Wilcox (Oracle)</name>
<email>willy@infradead.org</email>
</author>
<published>2023-12-28T08:57:43+00:00</published>
<link rel='alternate' type='text/html' href='http://mirrors.hust.edu.cn/git/lwn.git/commit/?id=e435ca87882167dda78776ce4bd6eb2094eb864b'/>
<id>urn:sha1:e435ca87882167dda78776ce4bd6eb2094eb864b</id>
<content type='text'>
Patch series "Remove some lruvec page accounting functions", v2.

Some functions are now unused; remove them.  Make
__mod_lruvec_page_state() unused and then remove it.


This patch (of 6):

All callers of these have been converted to their folio equivalents.

Link: https://lkml.kernel.org/r/20231228085748.1083901-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20231228085748.1083901-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Cc: Hyeonggon Yoo &lt;42.hyeyoo@gmail.com&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>mm: introduce per-VMA lock statistics</title>
<updated>2023-04-06T03:03:01+00:00</updated>
<author>
<name>Suren Baghdasaryan</name>
<email>surenb@google.com</email>
</author>
<published>2023-02-27T17:36:27+00:00</published>
<link rel='alternate' type='text/html' href='http://mirrors.hust.edu.cn/git/lwn.git/commit/?id=52f238653e452e0fda61e880f263a173d219acd1'/>
<id>urn:sha1:52f238653e452e0fda61e880f263a173d219acd1</id>
<content type='text'>
Add a new CONFIG_PER_VMA_LOCK_STATS config option to dump extra statistics
about handling page fault under VMA lock.

Link: https://lkml.kernel.org/r/20230227173632.3292573-29-surenb@google.com
Signed-off-by: Suren Baghdasaryan &lt;surenb@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>mm: remove vmacache</title>
<updated>2022-09-27T02:46:18+00:00</updated>
<author>
<name>Liam R. Howlett</name>
<email>Liam.Howlett@Oracle.com</email>
</author>
<published>2022-09-06T19:48:51+00:00</published>
<link rel='alternate' type='text/html' href='http://mirrors.hust.edu.cn/git/lwn.git/commit/?id=7964cf8caa4dfa42c4149f3833d3878713cda3dc'/>
<id>urn:sha1:7964cf8caa4dfa42c4149f3833d3878713cda3dc</id>
<content type='text'>
By using the maple tree and the maple tree state, the vmacache is no
longer beneficial and is complicating the VMA code.  Remove the vmacache
to reduce the work in keeping it up to date and code complexity.

Link: https://lkml.kernel.org/r/20220906194824.2110408-26-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett &lt;Liam.Howlett@Oracle.com&gt;
Acked-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Tested-by: Yu Zhao &lt;yuzhao@google.com&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: David Howells &lt;dhowells@redhat.com&gt;
Cc: Davidlohr Bueso &lt;dave@stgolabs.net&gt;
Cc: "Matthew Wilcox (Oracle)" &lt;willy@infradead.org&gt;
Cc: SeongJae Park &lt;sj@kernel.org&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>mm/workingset: Convert workingset_refault() to take a folio</title>
<updated>2021-10-18T11:49:40+00:00</updated>
<author>
<name>Matthew Wilcox (Oracle)</name>
<email>willy@infradead.org</email>
</author>
<published>2021-04-29T14:27:16+00:00</published>
<link rel='alternate' type='text/html' href='http://mirrors.hust.edu.cn/git/lwn.git/commit/?id=0995d7e568141226f10f8216aa4965e06ab5db8a'/>
<id>urn:sha1:0995d7e568141226f10f8216aa4965e06ab5db8a</id>
<content type='text'>
This nets us 178 bytes of savings from removing calls to compound_head.
The three callers all grow a little, but each of them will be converted
to use folios soon, so that's fine.

Signed-off-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: David Howells &lt;dhowells@redhat.com&gt;
Acked-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
</content>
</entry>
<entry>
<title>mm/vmstat: Add functions to account folio statistics</title>
<updated>2021-09-27T13:27:29+00:00</updated>
<author>
<name>Matthew Wilcox (Oracle)</name>
<email>willy@infradead.org</email>
</author>
<published>2021-01-18T13:14:00+00:00</published>
<link rel='alternate' type='text/html' href='http://mirrors.hust.edu.cn/git/lwn.git/commit/?id=a53e17e4e97b4519882d640984a386c522e9fba3'/>
<id>urn:sha1:a53e17e4e97b4519882d640984a386c522e9fba3</id>
<content type='text'>
Allow page counters to be more readily modified by callers which have
a folio.  Name these wrappers with 'stat' instead of 'state' as requested
by Linus here:
https://lore.kernel.org/linux-mm/CAHk-=wj847SudR-kt+46fT3+xFFgiwpgThvm7DJWGdi4cVrbnQ@mail.gmail.com/
No change to generated code.

Signed-off-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Acked-by: Jeff Layton &lt;jlayton@kernel.org&gt;
Acked-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Acked-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Reviewed-by: William Kucharski &lt;william.kucharski@oracle.com&gt;
Reviewed-by: David Howells &lt;dhowells@redhat.com&gt;
Acked-by: Mike Rapoport &lt;rppt@linux.ibm.com&gt;
</content>
</entry>
<entry>
<title>mm/page_alloc: batch the accounting updates in the bulk allocator</title>
<updated>2021-06-29T17:53:54+00:00</updated>
<author>
<name>Mel Gorman</name>
<email>mgorman@techsingularity.net</email>
</author>
<published>2021-06-29T02:41:50+00:00</published>
<link rel='alternate' type='text/html' href='http://mirrors.hust.edu.cn/git/lwn.git/commit/?id=3e23060b2d0b7eebf37b3b6043ea68da0ebc0646'/>
<id>urn:sha1:3e23060b2d0b7eebf37b3b6043ea68da0ebc0646</id>
<content type='text'>
Now that the zone_statistics are simple counters that do not require
special protection, the bulk allocator accounting updates can be batch
updated without adding too much complexity with protected RMW updates or
using xchg.

Link: https://lkml.kernel.org/r/20210512095458.30632-6-mgorman@techsingularity.net
Signed-off-by: Mel Gorman &lt;mgorman@techsingularity.net&gt;
Acked-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Acked-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: Chuck Lever &lt;chuck.lever@oracle.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Jesper Dangaard Brouer &lt;brouer@redhat.com&gt;
Cc: Michal Hocko &lt;mhocko@kernel.org&gt;
Cc: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
</feed>
