203 Commits
Author SHA1 Message Date
Linus Torvalds 4cff5c05e0 Merge tag 'mm-stable-2026-02-11-19-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:

 - "powerpc/64s: do not re-activate batched TLB flush" makes
   arch_{enter|leave}_lazy_mmu_mode() nest properly (Alexander Gordeev)

   It adds a generic enter/leave layer and switches architectures to use
   it. Various hacks were removed in the process.

 - "zram: introduce compressed data writeback" implements data
   compression for zram writeback (Richard Chang and Sergey Senozhatsky)

 - "mm: folio_zero_user: clear page ranges" adds clearing of contiguous
   page ranges for hugepages. Large improvements during demand faulting
   are demonstrated (David Hildenbrand)

 - "memcg cleanups" tidies up some memcg code (Chen Ridong)

 - "mm/damon: introduce {,max_}nr_snapshots and tracepoint for damos
   stats" improves DAMOS stat's provided information, deterministic
   control, and readability (SeongJae Park)

 - "selftests/mm: hugetlb cgroup charging: robustness fixes" fixes a few
   issues in the hugetlb cgroup charging selftests (Li Wang)

 - "Fix va_high_addr_switch.sh test failure - again" addresses several
   issues in the va_high_addr_switch test (Chunyu Hu)

 - "mm/damon/tests/core-kunit: extend existing test scenarios" improves
   the KUnit test coverage for DAMON (Shu Anzai)

 - "mm/khugepaged: fix dirty page handling for MADV_COLLAPSE" fixes a
   glitch in khugepaged which was causing madvise(MADV_COLLAPSE) to
   transiently return -EAGAIN (Shivank Garg)

 - "arch, mm: consolidate hugetlb early reservation" reworks and
   consolidates a pile of straggly code related to reservation of
   hugetlb memory from bootmem and creation of CMA areas for hugetlb
   (Mike Rapoport)

 - "mm: clean up anon_vma implementation" cleans up the anon_vma
   implementation in various ways (Lorenzo Stoakes)

 - "tweaks for __alloc_pages_slowpath()" does a little streamlining of
   the page allocator's slowpath code (Vlastimil Babka)

 - "memcg: separate private and public ID namespaces" cleans up the
   memcg ID code and prevents the internal-only private IDs from being
   exposed to userspace (Shakeel Butt)

 - "mm: hugetlb: allocate frozen gigantic folio" cleans up the
   allocation of frozen folios and avoids some atomic refcount
   operations (Kefeng Wang)

 - "mm/damon: advance DAMOS-based LRU sorting" improves DAMOS's movement
   of memory betewwn the active and inactive LRUs and adds auto-tuning
   of the ratio-based quotas and of monitoring intervals (SeongJae Park)

 - "Support page table check on PowerPC" makes
   CONFIG_PAGE_TABLE_CHECK_ENFORCED work on powerpc (Andrew Donnellan)

 - "nodemask: align nodes_and{,not} with underlying bitmap ops" makes
   nodes_and() and nodes_andnot() propagate the return values from the
   underlying bit operations, enabling some cleanup in calling code
   (Yury Norov)

 - "mm/damon: hide kdamond and kdamond_lock from API callers" cleans up
   some DAMON internal interfaces (SeongJae Park)

 - "mm/khugepaged: cleanups and scan limit fix" does some cleanup work
   in khupaged and fixes a scan limit accounting issue (Shivank Garg)

 - "mm: balloon infrastructure cleanups" goes to town on the balloon
   infrastructure and its page migration function. Mainly cleanups, also
   some locking simplification (David Hildenbrand)

 - "mm/vmscan: add tracepoint and reason for kswapd_failures reset" adds
   additional tracepoints to the page reclaim code (Jiayuan Chen)

 - "Replace wq users and add WQ_PERCPU to alloc_workqueue() users" is
   part of Marco's kernel-wide migration from the legacy workqueue APIs
   over to the preferred unbound workqueues (Marco Crivellari)

 - "Various mm kselftests improvements/fixes" provides various unrelated
   improvements/fixes for the mm kselftests (Kevin Brodsky)

 - "mm: accelerate gigantic folio allocation" greatly speeds up gigantic
   folio allocation, mainly by avoiding unnecessary work in
   pfn_range_valid_contig() (Kefeng Wang)

 - "selftests/damon: improve leak detection and wss estimation
   reliability" improves the reliability of two of the DAMON selftests
   (SeongJae Park)

 - "mm/damon: cleanup kdamond, damon_call(), damos filter and
   DAMON_MIN_REGION" does some cleanup work in the core DAMON code
   (SeongJae Park)

 - "Docs/mm/damon: update intro, modules, maintainer profile, and misc"
   performs maintenance work on the DAMON documentation (SeongJae Park)

 - "mm: add and use vma_assert_stabilised() helper" refactors and cleans
   up the core VMA code. The main aim here is to be able to use the mmap
   write lock's lockdep state to perform various assertions regarding
   the locking which the VMA code requires (Lorenzo Stoakes)

 - "mm, swap: swap table phase II: unify swapin use" removes some old
   swap code (swap cache bypassing and swap synchronization) which
   wasn't working very well. Various other cleanups and simplifications
   were made. The end result is a 20% speedup in one benchmark (Kairui
   Song)

 - "enable PT_RECLAIM on more 64-bit architectures" makes PT_RECLAIM
   available on 64-bit alpha, loongarch, mips, parisc, and um. Various
   cleanups were performed along the way (Qi Zheng)

* tag 'mm-stable-2026-02-11-19-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (325 commits)
  mm/memory: handle non-split locks correctly in zap_empty_pte_table()
  mm: move pte table reclaim code to memory.c
  mm: make PT_RECLAIM depends on MMU_GATHER_RCU_TABLE_FREE
  mm: convert __HAVE_ARCH_TLB_REMOVE_TABLE to CONFIG_HAVE_ARCH_TLB_REMOVE_TABLE config
  um: mm: enable MMU_GATHER_RCU_TABLE_FREE
  parisc: mm: enable MMU_GATHER_RCU_TABLE_FREE
  mips: mm: enable MMU_GATHER_RCU_TABLE_FREE
  LoongArch: mm: enable MMU_GATHER_RCU_TABLE_FREE
  alpha: mm: enable MMU_GATHER_RCU_TABLE_FREE
  mm: change mm/pt_reclaim.c to use asm/tlb.h instead of asm-generic/tlb.h
  mm/damon/stat: remove __read_mostly from memory_idle_ms_percentiles
  zsmalloc: make common caches global
  mm: add SPDX id lines to some mm source files
  mm/zswap: use %pe to print error pointers
  mm/vmscan: use %pe to print error pointers
  mm/readahead: fix typo in comment
  mm: khugepaged: fix NR_FILE_PAGES and NR_SHMEM in collapse_file()
  mm: refactor vma_map_pages to use vm_insert_pages
  mm/damon: unify address range representation with damon_addr_range
  mm/cma: replace snprintf with strscpy in cma_new_area
  ...
2026-02-12 11:32:37 -08:00
Wilson ZengandAndrew Morton ad1e0c44a4 mm/readahead: fix typo in comment
Fix a typo in a comment: max_readhead -> max_readahead.

Link: https://lkml.kernel.org/r/20260127152535.321951-1-cheng20011202@gmail.com
Signed-off-by: Wilson Zeng <cheng20011202@gmail.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-02-06 15:47:16 -08:00
Christoph HellwigandEric Biggers b244c89a70 readahead: push invalidate_lock out of page_cache_ra_unbounded
Require the invalidate_lock to be held over calls to
page_cache_ra_unbounded instead of acquiring it in this function.

This prepares for calling page_cache_ra_unbounded from ->readahead for
fsverity read-ahead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20260202060754.270269-3-hch@lst.de
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-02-02 12:38:13 -08:00
Matthew WilcoxandSean Christopherson 7f3779a3ac mm/filemap: Add NUMA mempolicy support to filemap_alloc_folio()
Add a mempolicy parameter to filemap_alloc_folio() to enable NUMA-aware
page cache allocations. This will be used by upcoming changes to
support NUMA policies in guest-memfd, where guest_memory need to be
allocated NUMA policy specified by VMM.

All existing users pass NULL maintaining current behavior.

Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Shivank Garg <shivankg@amd.com>
Tested-by: Ashish Kalra <ashish.kalra@amd.com>
Link: https://lore.kernel.org/r/20250827175247.83322-4-shivankg@amd.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-10-20 06:30:25 -07:00
Jan KaraandAndrew Morton 6028372689 readahead: add trace points
Add a couple of trace points to make debugging readahead logic easier.

[jack@suse.cz: v2]
  Link: https://lkml.kernel.org/r/20250909145849.5090-2-jack@suse.cz
Link: https://lkml.kernel.org/r/20250908145533.31528-2-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Tested-by: Pankaj Raghav <p.raghav@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-21 14:22:28 -07:00
Chi ZhilingandAndrew Morton c809579374 readahead: use folio_nr_pages() instead of shift operation
folio_nr_pages() is faster helper function to get the number of pages when
NR_PAGES_IN_LARGE_FOLIO is enabled.

Link: https://lkml.kernel.org/r/20250710060451.3535957-1-chizhiling@163.com
Signed-off-by: Chi Zhiling <chizhiling@kylinos.cn>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-19 18:59:53 -07:00
Ryan RobertsandAndrew Morton c4602f9fa7 mm/readahead: store folio order in struct file_ra_state
Previously the folio order of the previous readahead request was inferred
from the folio who's readahead marker was hit.  But due to the way we have
to round to non-natural boundaries sometimes, this first folio in the
readahead block is often smaller than the preferred order for that
request.  This means that for cases where the initial sync readahead is
poorly aligned, the folio order will ramp up much more slowly.

So instead, let's store the order in struct file_ra_state so we are not
affected by any required alignment.  We previously made enough room in the
struct for a 16 order field.  This should be plenty big enough since we
are limited to MAX_PAGECACHE_ORDER anyway, which is certainly never larger
than ~20.

Since we now pass order in struct file_ra_state, page_cache_ra_order() no
longer needs it's new_order parameter, so let's remove that.

Worked example:

Here we are touching pages 17-256 sequentially just as we did in the
previous commit, but now that we are remembering the preferred order
explicitly, we no longer have the slow ramp up problem.  Note specifically
that we no longer have 2 rounds (2x ~128K) of order-2 folios:

TYPE    STARTOFFS     ENDOFFS        SIZE  STARTPG    ENDPG   NRPG  ORDER  RA
-----  ----------  ----------  ----------  -------  -------  -----  -----  --
HOLE   0x00000000  0x00001000        4096        0        1      1
FOLIO  0x00001000  0x00002000        4096        1        2      1      0
FOLIO  0x00002000  0x00003000        4096        2        3      1      0
FOLIO  0x00003000  0x00004000        4096        3        4      1      0
FOLIO  0x00004000  0x00005000        4096        4        5      1      0
FOLIO  0x00005000  0x00006000        4096        5        6      1      0
FOLIO  0x00006000  0x00007000        4096        6        7      1      0
FOLIO  0x00007000  0x00008000        4096        7        8      1      0
FOLIO  0x00008000  0x00009000        4096        8        9      1      0
FOLIO  0x00009000  0x0000a000        4096        9       10      1      0
FOLIO  0x0000a000  0x0000b000        4096       10       11      1      0
FOLIO  0x0000b000  0x0000c000        4096       11       12      1      0
FOLIO  0x0000c000  0x0000d000        4096       12       13      1      0
FOLIO  0x0000d000  0x0000e000        4096       13       14      1      0
FOLIO  0x0000e000  0x0000f000        4096       14       15      1      0
FOLIO  0x0000f000  0x00010000        4096       15       16      1      0
FOLIO  0x00010000  0x00011000        4096       16       17      1      0
FOLIO  0x00011000  0x00012000        4096       17       18      1      0
FOLIO  0x00012000  0x00013000        4096       18       19      1      0
FOLIO  0x00013000  0x00014000        4096       19       20      1      0
FOLIO  0x00014000  0x00015000        4096       20       21      1      0
FOLIO  0x00015000  0x00016000        4096       21       22      1      0
FOLIO  0x00016000  0x00017000        4096       22       23      1      0
FOLIO  0x00017000  0x00018000        4096       23       24      1      0
FOLIO  0x00018000  0x00019000        4096       24       25      1      0
FOLIO  0x00019000  0x0001a000        4096       25       26      1      0
FOLIO  0x0001a000  0x0001b000        4096       26       27      1      0
FOLIO  0x0001b000  0x0001c000        4096       27       28      1      0
FOLIO  0x0001c000  0x0001d000        4096       28       29      1      0
FOLIO  0x0001d000  0x0001e000        4096       29       30      1      0
FOLIO  0x0001e000  0x0001f000        4096       30       31      1      0
FOLIO  0x0001f000  0x00020000        4096       31       32      1      0
FOLIO  0x00020000  0x00021000        4096       32       33      1      0
FOLIO  0x00021000  0x00022000        4096       33       34      1      0
FOLIO  0x00022000  0x00024000        8192       34       36      2      1
FOLIO  0x00024000  0x00028000       16384       36       40      4      2
FOLIO  0x00028000  0x0002c000       16384       40       44      4      2
FOLIO  0x0002c000  0x00030000       16384       44       48      4      2
FOLIO  0x00030000  0x00034000       16384       48       52      4      2
FOLIO  0x00034000  0x00038000       16384       52       56      4      2
FOLIO  0x00038000  0x0003c000       16384       56       60      4      2
FOLIO  0x0003c000  0x00040000       16384       60       64      4      2
FOLIO  0x00040000  0x00050000       65536       64       80     16      4
FOLIO  0x00050000  0x00060000       65536       80       96     16      4
FOLIO  0x00060000  0x00080000      131072       96      128     32      5
FOLIO  0x00080000  0x000a0000      131072      128      160     32      5
FOLIO  0x000a0000  0x000c0000      131072      160      192     32      5
FOLIO  0x000c0000  0x000e0000      131072      192      224     32      5
FOLIO  0x000e0000  0x00100000      131072      224      256     32      5
FOLIO  0x00100000  0x00120000      131072      256      288     32      5
FOLIO  0x00120000  0x00140000      131072      288      320     32      5  Y
HOLE   0x00140000  0x00800000     7077888      320     2048   1728

Link: https://lkml.kernel.org/r/20250609092729.274960-5-ryan.roberts@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Chaitanya S Prakash <chaitanyas.prakash@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09 22:42:03 -07:00
Ryan RobertsandAndrew Morton 18ebe55a92 mm/readahead: terminate async readahead on natural boundary
Previously asynchonous readahead would read ra_pages (usually 128K)
directly after the end of the synchonous readahead and given the
synchronous readahead portion had no alignment guarantees (beyond page
boundaries) it is possible (and likely) that the end of the initial 128K
region would not fall on a natural boundary for the folio size being used.
Therefore smaller folios were used to align down to the required
boundary, both at the end of the previous readahead block and at the start
of the new one.

In the worst cases, this can result in never properly ramping up the folio
size, and instead getting stuck oscillating between order-0, -1 and -2
folios.  The next readahead will try to use folios whose order is +2
bigger than the folio that had the readahead marker.  But because of the
alignment requirements, that folio (the first one in the readahead block)
can end up being order-0 in some cases.

There will be 2 modifications to solve this issue:

1) Calculate the readahead size so the end is aligned to a folio
   boundary. This prevents needing to allocate small folios to align
   down at the end of the window and fixes the oscillation problem.

2) Remember the "preferred folio order" in the ra state instead of
   inferring it from the folio with the readahead marker. This solves
   the slow ramp up problem (discussed in a subsequent patch).

This patch addresses (1) only. A subsequent patch will address (2).

Worked example:

The following shows the previous pathalogical behaviour when the initial
synchronous readahead is unaligned.  We start reading at page 17 in the
file and read sequentially from there.  I'm showing a dump of the pages in
the page cache just after we read the first page of the folio with the
readahead marker.

Initially there are no pages in the page cache:

TYPE    STARTOFFS     ENDOFFS        SIZE  STARTPG    ENDPG   NRPG  ORDER  RA
-----  ----------  ----------  ----------  -------  -------  -----  -----  --
HOLE   0x00000000  0x00800000     8388608        0     2048   2048

Then we access page 17, causing synchonous read-around of 128K with a
readahead marker set up at page 25. So far, all as expected:

TYPE    STARTOFFS     ENDOFFS        SIZE  STARTPG    ENDPG   NRPG  ORDER  RA
-----  ----------  ----------  ----------  -------  -------  -----  -----  --
HOLE   0x00000000  0x00001000        4096        0        1      1
FOLIO  0x00001000  0x00002000        4096        1        2      1      0
FOLIO  0x00002000  0x00003000        4096        2        3      1      0
FOLIO  0x00003000  0x00004000        4096        3        4      1      0
FOLIO  0x00004000  0x00005000        4096        4        5      1      0
FOLIO  0x00005000  0x00006000        4096        5        6      1      0
FOLIO  0x00006000  0x00007000        4096        6        7      1      0
FOLIO  0x00007000  0x00008000        4096        7        8      1      0
FOLIO  0x00008000  0x00009000        4096        8        9      1      0
FOLIO  0x00009000  0x0000a000        4096        9       10      1      0
FOLIO  0x0000a000  0x0000b000        4096       10       11      1      0
FOLIO  0x0000b000  0x0000c000        4096       11       12      1      0
FOLIO  0x0000c000  0x0000d000        4096       12       13      1      0
FOLIO  0x0000d000  0x0000e000        4096       13       14      1      0
FOLIO  0x0000e000  0x0000f000        4096       14       15      1      0
FOLIO  0x0000f000  0x00010000        4096       15       16      1      0
FOLIO  0x00010000  0x00011000        4096       16       17      1      0
FOLIO  0x00011000  0x00012000        4096       17       18      1      0
FOLIO  0x00012000  0x00013000        4096       18       19      1      0
FOLIO  0x00013000  0x00014000        4096       19       20      1      0
FOLIO  0x00014000  0x00015000        4096       20       21      1      0
FOLIO  0x00015000  0x00016000        4096       21       22      1      0
FOLIO  0x00016000  0x00017000        4096       22       23      1      0
FOLIO  0x00017000  0x00018000        4096       23       24      1      0
FOLIO  0x00018000  0x00019000        4096       24       25      1      0
FOLIO  0x00019000  0x0001a000        4096       25       26      1      0  Y
FOLIO  0x0001a000  0x0001b000        4096       26       27      1      0
FOLIO  0x0001b000  0x0001c000        4096       27       28      1      0
FOLIO  0x0001c000  0x0001d000        4096       28       29      1      0
FOLIO  0x0001d000  0x0001e000        4096       29       30      1      0
FOLIO  0x0001e000  0x0001f000        4096       30       31      1      0
FOLIO  0x0001f000  0x00020000        4096       31       32      1      0
FOLIO  0x00020000  0x00021000        4096       32       33      1      0
HOLE   0x00021000  0x00800000     8253440       33     2048   2015

Now access pages 18-25 inclusive.  This causes an asynchronous 128K
readahead starting at page 33.  But since we are unaligned, even though
the preferred folio order is 2, the first folio in this batch (the one
with the new readahead marker) is order-0:

TYPE    STARTOFFS     ENDOFFS        SIZE  STARTPG    ENDPG   NRPG  ORDER  RA
-----  ----------  ----------  ----------  -------  -------  -----  -----  --
HOLE   0x00000000  0x00001000        4096        0        1      1
FOLIO  0x00001000  0x00002000        4096        1        2      1      0
FOLIO  0x00002000  0x00003000        4096        2        3      1      0
FOLIO  0x00003000  0x00004000        4096        3        4      1      0
FOLIO  0x00004000  0x00005000        4096        4        5      1      0
FOLIO  0x00005000  0x00006000        4096        5        6      1      0
FOLIO  0x00006000  0x00007000        4096        6        7      1      0
FOLIO  0x00007000  0x00008000        4096        7        8      1      0
FOLIO  0x00008000  0x00009000        4096        8        9      1      0
FOLIO  0x00009000  0x0000a000        4096        9       10      1      0
FOLIO  0x0000a000  0x0000b000        4096       10       11      1      0
FOLIO  0x0000b000  0x0000c000        4096       11       12      1      0
FOLIO  0x0000c000  0x0000d000        4096       12       13      1      0
FOLIO  0x0000d000  0x0000e000        4096       13       14      1      0
FOLIO  0x0000e000  0x0000f000        4096       14       15      1      0
FOLIO  0x0000f000  0x00010000        4096       15       16      1      0
FOLIO  0x00010000  0x00011000        4096       16       17      1      0
FOLIO  0x00011000  0x00012000        4096       17       18      1      0
FOLIO  0x00012000  0x00013000        4096       18       19      1      0
FOLIO  0x00013000  0x00014000        4096       19       20      1      0
FOLIO  0x00014000  0x00015000        4096       20       21      1      0
FOLIO  0x00015000  0x00016000        4096       21       22      1      0
FOLIO  0x00016000  0x00017000        4096       22       23      1      0
FOLIO  0x00017000  0x00018000        4096       23       24      1      0
FOLIO  0x00018000  0x00019000        4096       24       25      1      0
FOLIO  0x00019000  0x0001a000        4096       25       26      1      0
FOLIO  0x0001a000  0x0001b000        4096       26       27      1      0
FOLIO  0x0001b000  0x0001c000        4096       27       28      1      0
FOLIO  0x0001c000  0x0001d000        4096       28       29      1      0
FOLIO  0x0001d000  0x0001e000        4096       29       30      1      0
FOLIO  0x0001e000  0x0001f000        4096       30       31      1      0
FOLIO  0x0001f000  0x00020000        4096       31       32      1      0
FOLIO  0x00020000  0x00021000        4096       32       33      1      0
FOLIO  0x00021000  0x00022000        4096       33       34      1      0  Y
FOLIO  0x00022000  0x00024000        8192       34       36      2      1
FOLIO  0x00024000  0x00028000       16384       36       40      4      2
FOLIO  0x00028000  0x0002c000       16384       40       44      4      2
FOLIO  0x0002c000  0x00030000       16384       44       48      4      2
FOLIO  0x00030000  0x00034000       16384       48       52      4      2
FOLIO  0x00034000  0x00038000       16384       52       56      4      2
FOLIO  0x00038000  0x0003c000       16384       56       60      4      2
FOLIO  0x0003c000  0x00040000       16384       60       64      4      2
FOLIO  0x00040000  0x00041000        4096       64       65      1      0
HOLE   0x00041000  0x00800000     8122368       65     2048   1983

Which means that when we now read pages 26-33 and readahead is kicked off
again, the new preferred order is 2 (0 + 2), not 4 as we intended:

TYPE    STARTOFFS     ENDOFFS        SIZE  STARTPG    ENDPG   NRPG  ORDER  RA
-----  ----------  ----------  ----------  -------  -------  -----  -----  --
HOLE   0x00000000  0x00001000        4096        0        1      1
FOLIO  0x00001000  0x00002000        4096        1        2      1      0
FOLIO  0x00002000  0x00003000        4096        2        3      1      0
FOLIO  0x00003000  0x00004000        4096        3        4      1      0
FOLIO  0x00004000  0x00005000        4096        4        5      1      0
FOLIO  0x00005000  0x00006000        4096        5        6      1      0
FOLIO  0x00006000  0x00007000        4096        6        7      1      0
FOLIO  0x00007000  0x00008000        4096        7        8      1      0
FOLIO  0x00008000  0x00009000        4096        8        9      1      0
FOLIO  0x00009000  0x0000a000        4096        9       10      1      0
FOLIO  0x0000a000  0x0000b000        4096       10       11      1      0
FOLIO  0x0000b000  0x0000c000        4096       11       12      1      0
FOLIO  0x0000c000  0x0000d000        4096       12       13      1      0
FOLIO  0x0000d000  0x0000e000        4096       13       14      1      0
FOLIO  0x0000e000  0x0000f000        4096       14       15      1      0
FOLIO  0x0000f000  0x00010000        4096       15       16      1      0
FOLIO  0x00010000  0x00011000        4096       16       17      1      0
FOLIO  0x00011000  0x00012000        4096       17       18      1      0
FOLIO  0x00012000  0x00013000        4096       18       19      1      0
FOLIO  0x00013000  0x00014000        4096       19       20      1      0
FOLIO  0x00014000  0x00015000        4096       20       21      1      0
FOLIO  0x00015000  0x00016000        4096       21       22      1      0
FOLIO  0x00016000  0x00017000        4096       22       23      1      0
FOLIO  0x00017000  0x00018000        4096       23       24      1      0
FOLIO  0x00018000  0x00019000        4096       24       25      1      0
FOLIO  0x00019000  0x0001a000        4096       25       26      1      0
FOLIO  0x0001a000  0x0001b000        4096       26       27      1      0
FOLIO  0x0001b000  0x0001c000        4096       27       28      1      0
FOLIO  0x0001c000  0x0001d000        4096       28       29      1      0
FOLIO  0x0001d000  0x0001e000        4096       29       30      1      0
FOLIO  0x0001e000  0x0001f000        4096       30       31      1      0
FOLIO  0x0001f000  0x00020000        4096       31       32      1      0
FOLIO  0x00020000  0x00021000        4096       32       33      1      0
FOLIO  0x00021000  0x00022000        4096       33       34      1      0
FOLIO  0x00022000  0x00024000        8192       34       36      2      1
FOLIO  0x00024000  0x00028000       16384       36       40      4      2
FOLIO  0x00028000  0x0002c000       16384       40       44      4      2
FOLIO  0x0002c000  0x00030000       16384       44       48      4      2
FOLIO  0x00030000  0x00034000       16384       48       52      4      2
FOLIO  0x00034000  0x00038000       16384       52       56      4      2
FOLIO  0x00038000  0x0003c000       16384       56       60      4      2
FOLIO  0x0003c000  0x00040000       16384       60       64      4      2
FOLIO  0x00040000  0x00041000        4096       64       65      1      0
FOLIO  0x00041000  0x00042000        4096       65       66      1      0  Y
FOLIO  0x00042000  0x00044000        8192       66       68      2      1
FOLIO  0x00044000  0x00048000       16384       68       72      4      2
FOLIO  0x00048000  0x0004c000       16384       72       76      4      2
FOLIO  0x0004c000  0x00050000       16384       76       80      4      2
FOLIO  0x00050000  0x00054000       16384       80       84      4      2
FOLIO  0x00054000  0x00058000       16384       84       88      4      2
FOLIO  0x00058000  0x0005c000       16384       88       92      4      2
FOLIO  0x0005c000  0x00060000       16384       92       96      4      2
FOLIO  0x00060000  0x00061000        4096       96       97      1      0
HOLE   0x00061000  0x00800000     7991296       97     2048   1951

This ramp up from order-0 with smaller orders at the edges for alignment
cycle continues all the way to the end of the file (not shown).

After the change, we round down the end boundary to the order boundary so
we no longer get stuck in the cycle and can ramp up the order over time. 
Note that the rate of the ramp up is still not as we would expect it.  We
will fix that next.  Here we are touching pages 17-256 sequentially:

TYPE    STARTOFFS     ENDOFFS        SIZE  STARTPG    ENDPG   NRPG  ORDER  RA
-----  ----------  ----------  ----------  -------  -------  -----  -----  --
HOLE   0x00000000  0x00001000        4096        0        1      1
FOLIO  0x00001000  0x00002000        4096        1        2      1      0
FOLIO  0x00002000  0x00003000        4096        2        3      1      0
FOLIO  0x00003000  0x00004000        4096        3        4      1      0
FOLIO  0x00004000  0x00005000        4096        4        5      1      0
FOLIO  0x00005000  0x00006000        4096        5        6      1      0
FOLIO  0x00006000  0x00007000        4096        6        7      1      0
FOLIO  0x00007000  0x00008000        4096        7        8      1      0
FOLIO  0x00008000  0x00009000        4096        8        9      1      0
FOLIO  0x00009000  0x0000a000        4096        9       10      1      0
FOLIO  0x0000a000  0x0000b000        4096       10       11      1      0
FOLIO  0x0000b000  0x0000c000        4096       11       12      1      0
FOLIO  0x0000c000  0x0000d000        4096       12       13      1      0
FOLIO  0x0000d000  0x0000e000        4096       13       14      1      0
FOLIO  0x0000e000  0x0000f000        4096       14       15      1      0
FOLIO  0x0000f000  0x00010000        4096       15       16      1      0
FOLIO  0x00010000  0x00011000        4096       16       17      1      0
FOLIO  0x00011000  0x00012000        4096       17       18      1      0
FOLIO  0x00012000  0x00013000        4096       18       19      1      0
FOLIO  0x00013000  0x00014000        4096       19       20      1      0
FOLIO  0x00014000  0x00015000        4096       20       21      1      0
FOLIO  0x00015000  0x00016000        4096       21       22      1      0
FOLIO  0x00016000  0x00017000        4096       22       23      1      0
FOLIO  0x00017000  0x00018000        4096       23       24      1      0
FOLIO  0x00018000  0x00019000        4096       24       25      1      0
FOLIO  0x00019000  0x0001a000        4096       25       26      1      0
FOLIO  0x0001a000  0x0001b000        4096       26       27      1      0
FOLIO  0x0001b000  0x0001c000        4096       27       28      1      0
FOLIO  0x0001c000  0x0001d000        4096       28       29      1      0
FOLIO  0x0001d000  0x0001e000        4096       29       30      1      0
FOLIO  0x0001e000  0x0001f000        4096       30       31      1      0
FOLIO  0x0001f000  0x00020000        4096       31       32      1      0
FOLIO  0x00020000  0x00021000        4096       32       33      1      0
FOLIO  0x00021000  0x00022000        4096       33       34      1      0
FOLIO  0x00022000  0x00024000        8192       34       36      2      1
FOLIO  0x00024000  0x00028000       16384       36       40      4      2
FOLIO  0x00028000  0x0002c000       16384       40       44      4      2
FOLIO  0x0002c000  0x00030000       16384       44       48      4      2
FOLIO  0x00030000  0x00034000       16384       48       52      4      2
FOLIO  0x00034000  0x00038000       16384       52       56      4      2
FOLIO  0x00038000  0x0003c000       16384       56       60      4      2
FOLIO  0x0003c000  0x00040000       16384       60       64      4      2
FOLIO  0x00040000  0x00044000       16384       64       68      4      2
FOLIO  0x00044000  0x00048000       16384       68       72      4      2
FOLIO  0x00048000  0x0004c000       16384       72       76      4      2
FOLIO  0x0004c000  0x00050000       16384       76       80      4      2
FOLIO  0x00050000  0x00054000       16384       80       84      4      2
FOLIO  0x00054000  0x00058000       16384       84       88      4      2
FOLIO  0x00058000  0x0005c000       16384       88       92      4      2
FOLIO  0x0005c000  0x00060000       16384       92       96      4      2
FOLIO  0x00060000  0x00070000       65536       96      112     16      4
FOLIO  0x00070000  0x00080000       65536      112      128     16      4
FOLIO  0x00080000  0x000a0000      131072      128      160     32      5
FOLIO  0x000a0000  0x000c0000      131072      160      192     32      5
FOLIO  0x000c0000  0x000e0000      131072      192      224     32      5
FOLIO  0x000e0000  0x00100000      131072      224      256     32      5
FOLIO  0x00100000  0x00120000      131072      256      288     32      5
FOLIO  0x00120000  0x00140000      131072      288      320     32      5  Y
HOLE   0x00140000  0x00800000     7077888      320     2048   1728

Link: https://lkml.kernel.org/r/20250609092729.274960-3-ryan.roberts@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Chaitanya S Prakash <chaitanyas.prakash@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09 22:42:02 -07:00
Ryan RobertsandAndrew Morton bdb86f6b87 mm/readahead: honour new_order in page_cache_ra_order()
Patch series "Readahead tweaks for larger folios", v5.

This series adds some tweaks to readahead so that it does a better job of
ramping up folio sizes as readahead extends further into the file.  And it
additionally special-cases executable mappings to allow the arch to
request a preferred folio size for text.


This patch (of 5):

page_cache_ra_order() takes a parameter called new_order, which is
intended to express the preferred order of the folios that will be
allocated for the readahead operation.  Most callers indeed call this with
their preferred new order.  But page_cache_async_ra() calls it with the
preferred order of the previous readahead request (actually the order of
the folio that had the readahead marker, which may be smaller when
alignment comes into play).

And despite the parameter name, page_cache_ra_order() always treats it at
the old order, adding 2 to it on entry.  As a result, a cold readahead
always starts with order-2 folios.

Let's fix this behaviour by always passing in the *new* order.

Worked example:

Prior to the change, mmaping an 8MB file and touching each page
sequentially, resulted in the following, where we start with order-2
folios for the first 128K then ramp up to order-4 for the next 128K, then
get clamped to order-5 for the rest of the file because pa_pages is
limited to 128K:

TYPE    STARTOFFS     ENDOFFS       SIZE  STARTPG    ENDPG   NRPG  ORDER
-----  ----------  ----------  ---------  -------  -------  -----  -----
FOLIO  0x00000000  0x00004000      16384        0        4      4      2
FOLIO  0x00004000  0x00008000      16384        4        8      4      2
FOLIO  0x00008000  0x0000c000      16384        8       12      4      2
FOLIO  0x0000c000  0x00010000      16384       12       16      4      2
FOLIO  0x00010000  0x00014000      16384       16       20      4      2
FOLIO  0x00014000  0x00018000      16384       20       24      4      2
FOLIO  0x00018000  0x0001c000      16384       24       28      4      2
FOLIO  0x0001c000  0x00020000      16384       28       32      4      2
FOLIO  0x00020000  0x00030000      65536       32       48     16      4
FOLIO  0x00030000  0x00040000      65536       48       64     16      4
FOLIO  0x00040000  0x00060000     131072       64       96     32      5
FOLIO  0x00060000  0x00080000     131072       96      128     32      5
FOLIO  0x00080000  0x000a0000     131072      128      160     32      5
FOLIO  0x000a0000  0x000c0000     131072      160      192     32      5
...

After the change, the same operation results in the first 128K being
order-0, then we start ramping up to order-2, -4, and finally get clamped
at order-5:

TYPE    STARTOFFS     ENDOFFS       SIZE  STARTPG    ENDPG   NRPG  ORDER
-----  ----------  ----------  ---------  -------  -------  -----  -----
FOLIO  0x00000000  0x00001000       4096        0        1      1      0
FOLIO  0x00001000  0x00002000       4096        1        2      1      0
FOLIO  0x00002000  0x00003000       4096        2        3      1      0
FOLIO  0x00003000  0x00004000       4096        3        4      1      0
FOLIO  0x00004000  0x00005000       4096        4        5      1      0
FOLIO  0x00005000  0x00006000       4096        5        6      1      0
FOLIO  0x00006000  0x00007000       4096        6        7      1      0
FOLIO  0x00007000  0x00008000       4096        7        8      1      0
FOLIO  0x00008000  0x00009000       4096        8        9      1      0
FOLIO  0x00009000  0x0000a000       4096        9       10      1      0
FOLIO  0x0000a000  0x0000b000       4096       10       11      1      0
FOLIO  0x0000b000  0x0000c000       4096       11       12      1      0
FOLIO  0x0000c000  0x0000d000       4096       12       13      1      0
FOLIO  0x0000d000  0x0000e000       4096       13       14      1      0
FOLIO  0x0000e000  0x0000f000       4096       14       15      1      0
FOLIO  0x0000f000  0x00010000       4096       15       16      1      0
FOLIO  0x00010000  0x00011000       4096       16       17      1      0
FOLIO  0x00011000  0x00012000       4096       17       18      1      0
FOLIO  0x00012000  0x00013000       4096       18       19      1      0
FOLIO  0x00013000  0x00014000       4096       19       20      1      0
FOLIO  0x00014000  0x00015000       4096       20       21      1      0
FOLIO  0x00015000  0x00016000       4096       21       22      1      0
FOLIO  0x00016000  0x00017000       4096       22       23      1      0
FOLIO  0x00017000  0x00018000       4096       23       24      1      0
FOLIO  0x00018000  0x00019000       4096       24       25      1      0
FOLIO  0x00019000  0x0001a000       4096       25       26      1      0
FOLIO  0x0001a000  0x0001b000       4096       26       27      1      0
FOLIO  0x0001b000  0x0001c000       4096       27       28      1      0
FOLIO  0x0001c000  0x0001d000       4096       28       29      1      0
FOLIO  0x0001d000  0x0001e000       4096       29       30      1      0
FOLIO  0x0001e000  0x0001f000       4096       30       31      1      0
FOLIO  0x0001f000  0x00020000       4096       31       32      1      0
FOLIO  0x00020000  0x00024000      16384       32       36      4      2
FOLIO  0x00024000  0x00028000      16384       36       40      4      2
FOLIO  0x00028000  0x0002c000      16384       40       44      4      2
FOLIO  0x0002c000  0x00030000      16384       44       48      4      2
FOLIO  0x00030000  0x00034000      16384       48       52      4      2
FOLIO  0x00034000  0x00038000      16384       52       56      4      2
FOLIO  0x00038000  0x0003c000      16384       56       60      4      2
FOLIO  0x0003c000  0x00040000      16384       60       64      4      2
FOLIO  0x00040000  0x00050000      65536       64       80     16      4
FOLIO  0x00050000  0x00060000      65536       80       96     16      4
FOLIO  0x00060000  0x00080000     131072       96      128     32      5
FOLIO  0x00080000  0x000a0000     131072      128      160     32      5
FOLIO  0x000a0000  0x000c0000     131072      160      192     32      5
FOLIO  0x000c0000  0x000e0000     131072      192      224     32      5
...

Link: https://lkml.kernel.org/r/20250609092729.274960-1-ryan.roberts@arm.com
Link: https://lkml.kernel.org/r/20250609092729.274960-2-ryan.roberts@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Tested-by: Chaitanya S Prakash <chaitanyas.prakash@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09 22:42:02 -07:00
Christian Brauner 19bbfe7b5f fs: add S_ANON_INODE
This makes it easy to detect proper anonymous inodes and to ensure that
we can detect them in codepaths such as readahead().

Readahead on anonymous inodes didn't work because they didn't have a
proper mode. Now that they have we need to retain EINVAL being returned
otherwise LTP will fail.

We also need to ensure that ioctls aren't simply fired like they are for
regular files so things like inotify inodes continue to correctly call
their own ioctl handlers as in [1].

Reported-by: Xilin Wu <sophon@radxa.com>
Link: https://lore.kernel.org/3A9139D5CD543962+89831381-31b9-4392-87ec-a84a5b3507d8@radxa.com [1]
Link: https://lore.kernel.org/7a1a7076-ff6b-4cb0-94e7-7218a0a44028@sirena.org.uk
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-04-21 13:20:14 +02:00
Amir GoldsteinandJan Kara 252256e416 Revert "fanotify: disable readahead if we have pre-content watches"
This reverts commit fac84846a2.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20250312073852.2123409-7-amir73il@gmail.com
2025-03-13 16:31:12 +01:00
Linus Torvalds 9c5968db9e Merge tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
 "The various patchsets are summarized below. Plus of course many
  indivudual patches which are described in their changelogs.

   - "Allocate and free frozen pages" from Matthew Wilcox reorganizes
     the page allocator so we end up with the ability to allocate and
     free zero-refcount pages. So that callers (ie, slab) can avoid a
     refcount inc & dec

   - "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to
     use large folios other than PMD-sized ones

   - "Fix mm/rodata_test" from Petr Tesarik performs some maintenance
     and fixes for this small built-in kernel selftest

   - "mas_anode_descend() related cleanup" from Wei Yang tidies up part
     of the mapletree code

   - "mm: fix format issues and param types" from Keren Sun implements a
     few minor code cleanups

   - "simplify split calculation" from Wei Yang provides a few fixes and
     a test for the mapletree code

   - "mm/vma: make more mmap logic userland testable" from Lorenzo
     Stoakes continues the work of moving vma-related code into the
     (relatively) new mm/vma.c

   - "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David
     Hildenbrand cleans up and rationalizes handling of gfp flags in the
     page allocator

   - "readahead: Reintroduce fix for improper RA window sizing" from Jan
     Kara is a second attempt at fixing a readahead window sizing issue.
     It should reduce the amount of unnecessary reading

   - "synchronously scan and reclaim empty user PTE pages" from Qi Zheng
     addresses an issue where "huge" amounts of pte pagetables are
     accumulated:

       https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/

     Qi's series addresses this windup by synchronously freeing PTE
     memory within the context of madvise(MADV_DONTNEED)

   - "selftest/mm: Remove warnings found by adding compiler flags" from
     Muhammad Usama Anjum fixes some build warnings in the selftests
     code when optional compiler warnings are enabled

   - "mm: don't use __GFP_HARDWALL when migrating remote pages" from
     David Hildenbrand tightens the allocator's observance of
     __GFP_HARDWALL

   - "pkeys kselftests improvements" from Kevin Brodsky implements
     various fixes and cleanups in the MM selftests code, mainly
     pertaining to the pkeys tests

   - "mm/damon: add sample modules" from SeongJae Park enhances DAMON to
     estimate application working set size

   - "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn
     provides some cleanups to memcg's hugetlb charging logic

   - "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song
     removes the global swap cgroup lock. A speedup of 10% for a
     tmpfs-based kernel build was demonstrated

   - "zram: split page type read/write handling" from Sergey Senozhatsky
     has several fixes and cleaups for zram in the area of
     zram_write_page(). A watchdog softlockup warning was eliminated

   - "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin
     Brodsky cleans up the pagetable destructor implementations. A rare
     use-after-free race is fixed

   - "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes
     simplifies and cleans up the debugging code in the VMA merging
     logic

   - "Account page tables at all levels" from Kevin Brodsky cleans up
     and regularizes the pagetable ctor/dtor handling. This results in
     improvements in accounting accuracy

   - "mm/damon: replace most damon_callback usages in sysfs with new
     core functions" from SeongJae Park cleans up and generalizes
     DAMON's sysfs file interface logic

   - "mm/damon: enable page level properties based monitoring" from
     SeongJae Park increases the amount of information which is
     presented in response to DAMOS actions

   - "mm/damon: remove DAMON debugfs interface" from SeongJae Park
     removes DAMON's long-deprecated debugfs interfaces. Thus the
     migration to sysfs is completed

   - "mm/hugetlb: Refactor hugetlb allocation resv accounting" from
     Peter Xu cleans up and generalizes the hugetlb reservation
     accounting

   - "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino
     removes a never-used feature of the alloc_pages_bulk() interface

   - "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park
     extends DAMOS filters to support not only exclusion (rejecting),
     but also inclusion (allowing) behavior

   - "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi
     introduces a new memory descriptor for zswap.zpool that currently
     overlaps with struct page for now. This is part of the effort to
     reduce the size of struct page and to enable dynamic allocation of
     memory descriptors

   - "mm, swap: rework of swap allocator locks" from Kairui Song redoes
     and simplifies the swap allocator locking. A speedup of 400% was
     demonstrated for one workload. As was a 35% reduction for kernel
     build time with swap-on-zram

   - "mm: update mips to use do_mmap(), make mmap_region() internal"
     from Lorenzo Stoakes reworks MIPS's use of mmap_region() so that
     mmap_region() can be made MM-internal

   - "mm/mglru: performance optimizations" from Yu Zhao fixes a few
     MGLRU regressions and otherwise improves MGLRU performance

   - "Docs/mm/damon: add tuning guide and misc updates" from SeongJae
     Park updates DAMON documentation

   - "Cleanup for memfd_create()" from Isaac Manjarres does that thing

   - "mm: hugetlb+THP folio and migration cleanups" from David
     Hildenbrand provides various cleanups in the areas of hugetlb
     folios, THP folios and migration

   - "Uncached buffered IO" from Jens Axboe implements the new
     RWF_DONTCACHE flag which provides synchronous dropbehind for
     pagecache reading and writing. To permite userspace to address
     issues with massive buildup of useless pagecache when
     reading/writing fast devices

   - "selftests/mm: virtual_address_range: Reduce memory" from Thomas
     Weißschuh fixes and optimizes some of the MM selftests"

* tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits)
  mm/compaction: fix UBSAN shift-out-of-bounds warning
  s390/mm: add missing ctor/dtor on page table upgrade
  kasan: sw_tags: use str_on_off() helper in kasan_init_sw_tags()
  tools: add VM_WARN_ON_VMG definition
  mm/damon/core: use str_high_low() helper in damos_wmark_wait_us()
  seqlock: add missing parameter documentation for raw_seqcount_try_begin()
  mm/page-writeback: consolidate wb_thresh bumping logic into __wb_calc_thresh
  mm/page_alloc: remove the incorrect and misleading comment
  zram: remove zcomp_stream_put() from write_incompressible_page()
  mm: separate move/undo parts from migrate_pages_batch()
  mm/kfence: use str_write_read() helper in get_access_type()
  selftests/mm/mkdirty: fix memory leak in test_uffdio_copy()
  kasan: hw_tags: Use str_on_off() helper in kasan_init_hw_tags()
  selftests/mm: virtual_address_range: avoid reading from VM_IO mappings
  selftests/mm: vm_util: split up /proc/self/smaps parsing
  selftests/mm: virtual_address_range: unmap chunks after validation
  selftests/mm: virtual_address_range: mmap() without PROT_WRITE
  selftests/memfd/memfd_test: fix possible NULL pointer dereference
  mm: add FGP_DONTCACHE folio creation flag
  mm: call filemap_fdatawrite_range_kick() after IOCB_DONTCACHE issue
  ...
2025-01-26 18:36:23 -08:00
Jens AxboeandAndrew Morton 77d075221a mm/readahead: add readahead_control->dropbehind member
If ractl->dropbehind is set to true, then folios created are marked as
dropbehind as well.

Link: https://lkml.kernel.org/r/20241220154831.1086649-6-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Brian Foster <bfoster@redhat.com>
Cc: Chris Mason <clm@meta.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25 20:22:43 -08:00
Jens AxboeandAndrew Morton 1963de79d3 mm/readahead: add folio allocation helper
Just a wrapper around filemap_alloc_folio() for now, but add it in
preparation for modifying the folio based on the 'ractl' being passed in.

No functional changes in this patch.

Link: https://lkml.kernel.org/r/20241220154831.1086649-4-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Brian Foster <bfoster@redhat.com>
Cc: Chris Mason <clm@meta.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25 20:22:42 -08:00
Linus Torvalds 8883957b3c Merge tag 'fsnotify_hsm_for_v6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull fsnotify pre-content notification support from Jan Kara:
 "This introduces a new fsnotify event (FS_PRE_ACCESS) that gets
  generated before a file contents is accessed.

  The event is synchronous so if there is listener for this event, the
  kernel waits for reply. On success the execution continues as usual,
  on failure we propagate the error to userspace. This allows userspace
  to fill in file content on demand from slow storage. The context in
  which the events are generated has been picked so that we don't hold
  any locks and thus there's no risk of a deadlock for the userspace
  handler.

  The new pre-content event is available only for users with global
  CAP_SYS_ADMIN capability (similarly to other parts of fanotify
  functionality) and it is an administrator responsibility to make sure
  the userspace event handler doesn't do stupid stuff that can DoS the
  system.

  Based on your feedback from the last submission, fsnotify code has
  been improved and now file->f_mode encodes whether pre-content event
  needs to be generated for the file so the fast path when nobody wants
  pre-content event for the file just grows the additional file->f_mode
  check. As a bonus this also removes the checks whether the old
  FS_ACCESS event needs to be generated from the fast path. Also the
  place where the event is generated during page fault has been moved so
  now filemap_fault() generates the event if and only if there is no
  uptodate folio in the page cache.

  Also we have dropped FS_PRE_MODIFY event as current real-world users
  of the pre-content functionality don't really use it so let's start
  with the minimal useful feature set"

* tag 'fsnotify_hsm_for_v6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: (21 commits)
  fanotify: Fix crash in fanotify_init(2)
  fs: don't block write during exec on pre-content watched files
  fs: enable pre-content events on supported file systems
  ext4: add pre-content fsnotify hook for DAX faults
  btrfs: disable defrag on pre-content watched files
  xfs: add pre-content fsnotify hook for DAX faults
  fsnotify: generate pre-content permission event on page fault
  mm: don't allow huge faults for files with pre content watches
  fanotify: disable readahead if we have pre-content watches
  fanotify: allow to set errno in FAN_DENY permission response
  fanotify: report file range info with pre-content events
  fanotify: introduce FAN_PRE_ACCESS permission event
  fsnotify: generate pre-content permission event on truncate
  fsnotify: pass optional file access range in pre-content event
  fsnotify: introduce pre-content permission events
  fanotify: reserve event bit of deprecated FAN_DIR_MODIFY
  fanotify: rename a misnamed constant
  fanotify: don't skip extra event info if no info_mode is set
  fsnotify: check if file is actually being watched for pre-content events on open
  fsnotify: opt-in for permission events at file open time
  ...
2025-01-23 13:36:06 -08:00
Jan KaraandAndrew Morton d5ea5e5e50 readahead: properly shorten readahead when falling back to do_page_cache_ra()
When we succeed in creating some folios in page_cache_ra_order() but then
need to fallback to single page folios, we don't shorten the amount to
read passed to do_page_cache_ra() by the amount we've already read.  This
then results in reading more and also in placing another readahead mark in
the middle of the readahead window which confuses readahead code.  Fix the
problem by properly reducing number of pages to read.  Unlike previous
attempt at this fix (commit 7c877586da) which had to be reverted, we are
now careful to check there is indeed something to read so that we don't
submit negative-sized readahead.

Link: https://lkml.kernel.org/r/20241204181016.15273-3-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-13 22:40:45 -08:00
Jan KaraandAndrew Morton 7a1eb89f79 readahead: don't shorten readahead window in read_pages()
Patch series "readahead: Reintroduce fix for improper RA window sizing".

This small patch series reintroduces a fix of readahead window confusion
(and thus read throughput reduction) when page_cache_ra_order() ends up
failing due to folios already present in the page cache.  After thinking
about this for a while I have ended up with a dumb fix that just rechecks
if we have something to read before calling do_page_cache_ra().  This
fixes the problem reported in [1].  I still think it doesn't make much
sense to update readahead window size in read_pages() so patch 1 removes
that but the real fix in patch 2 does not depend on it.

[1] https://lore.kernel.org/all/49648605-d800-4859-be49-624bbe60519d@gmail.com
								

This patch (of 2):

When ->readahead callback doesn't read all requested pages, read_pages()
shortens the readahead window (ra->size).  However we don't know why pages
were not read and what appropriate window size is.  So don't try to
secondguess the filesystem.  If it needs different readahead window, it
should set it manually similarly as during expansion the filesystem can
use readahead_expand().

Link: https://lkml.kernel.org/r/20241204181016.15273-1-jack@suse.cz
Link: https://lkml.kernel.org/r/20241204181016.15273-2-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-13 22:40:45 -08:00
Yafang ShaoandAndrew Morton 158cdce87c mm/readahead: fix large folio support in async readahead
When testing large folio support with XFS on our servers, we observed that
only a few large folios are mapped when reading large files via mmap. 
After a thorough analysis, I identified it was caused by the
`/sys/block/*/queue/read_ahead_kb` setting.  On our test servers, this
parameter is set to 128KB.  After I tune it to 2MB, the large folio can
work as expected.  However, I believe the large folio behavior should not
be dependent on the value of read_ahead_kb.  It would be more robust if
the kernel can automatically adopt to it.

With /sys/block/*/queue/read_ahead_kb set to 128KB and performing a
sequential read on a 1GB file using MADV_HUGEPAGE, the differences in
/proc/meminfo are as follows:

- before this patch
  FileHugePages:     18432 kB
  FilePmdMapped:      4096 kB

- after this patch
  FileHugePages:   1067008 kB
  FilePmdMapped:   1048576 kB

This shows that after applying the patch, the entire 1GB file is mapped to
huge pages.  The stable list is CCed, as without this patch, large folios
don't function optimally in the readahead path.

It's worth noting that if read_ahead_kb is set to a larger value that
isn't aligned with huge page sizes (e.g., 4MB + 128KB), it may still fail
to map to hugepages.

Link: https://lkml.kernel.org/r/20241108141710.9721-1-laoar.shao@gmail.com
Link: https://lkml.kernel.org/r/20241206083025.3478-1-laoar.shao@gmail.com
Fixes: 4687fdbb80 ("mm/filemap: Support VM_HUGEPAGE for file mappings")
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Tested-by: kernel test robot <oliver.sang@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-12-30 17:59:07 -08:00
Josef BacikandJan Kara fac84846a2 fanotify: disable readahead if we have pre-content watches
With page faults we can trigger readahead on the file, and then
subsequent faults can find these pages and insert them into the file
without emitting an fanotify event.  To avoid this case, disable
readahead if we have pre-content watches on the file.  This way we are
guaranteed to get an event for every range we attempt to access on a
pre-content watched file.

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/70a54e859f555e54bc7a47b32fe5aca92b085615.1731684329.git.josef@toxicpanda.com
2024-12-10 12:03:17 +01:00
Jan KaraandAndrew Morton a220d6b95b Revert "readahead: properly shorten readahead when falling back to do_page_cache_ra()"
This reverts commit 7c877586da.

Anders and Philippe have reported that recent kernels occasionally hang
when used with NFS in readahead code.  The problem has been bisected to
7c877586da ("readahead: properly shorten readahead when falling back to
do_page_cache_ra()").  The cause of the problem is that ra->size can be
shrunk by read_pages() call and subsequently we end up calling
do_page_cache_ra() with negative (read huge positive) number of pages. 
Let's revert 7c877586da for now until we can find a proper way how the
logic in read_pages() and page_cache_ra_order() can coexist.  This can
lead to reduced readahead throughput due to readahead window confusion but
that's better than outright hangs.

Link: https://lkml.kernel.org/r/20241126145208.985-1-jack@suse.cz
Fixes: 7c877586da ("readahead: properly shorten readahead when falling back to do_page_cache_ra()")
Reported-by: Anders Blomdell <anders.blomdell@gmail.com>
Reported-by: Philippe Troin <phil@fifi.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Tested-by: Philippe Troin <phil@fifi.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-12-05 19:54:44 -08:00
Linus Torvalds 5c00ff742b Merge tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:

 - The series "zram: optimal post-processing target selection" from
   Sergey Senozhatsky improves zram's post-processing selection
   algorithm. This leads to improved memory savings.

 - Wei Yang has gone to town on the mapletree code, contributing several
   series which clean up the implementation:
	- "refine mas_mab_cp()"
	- "Reduce the space to be cleared for maple_big_node"
	- "maple_tree: simplify mas_push_node()"
	- "Following cleanup after introduce mas_wr_store_type()"
	- "refine storing null"

 - The series "selftests/mm: hugetlb_fault_after_madv improvements" from
   David Hildenbrand fixes this selftest for s390.

 - The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng
   implements some rationaizations and cleanups in the page mapping
   code.

 - The series "mm: optimize shadow entries removal" from Shakeel Butt
   optimizes the file truncation code by speeding up the handling of
   shadow entries.

 - The series "Remove PageKsm()" from Matthew Wilcox completes the
   migration of this flag over to being a folio-based flag.

 - The series "Unify hugetlb into arch_get_unmapped_area functions" from
   Oscar Salvador implements a bunch of consolidations and cleanups in
   the hugetlb code.

 - The series "Do not shatter hugezeropage on wp-fault" from Dev Jain
   takes away the wp-fault time practice of turning a huge zero page
   into small pages. Instead we replace the whole thing with a THP. More
   consistent cleaner and potentiall saves a large number of pagefaults.

 - The series "percpu: Add a test case and fix for clang" from Andy
   Shevchenko enhances and fixes the kernel's built in percpu test code.

 - The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett
   optimizes mremap() by avoiding doing things which we didn't need to
   do.

 - The series "Improve the tmpfs large folio read performance" from
   Baolin Wang teaches tmpfs to copy data into userspace at the folio
   size rather than as individual pages. A 20% speedup was observed.

 - The series "mm/damon/vaddr: Fix issue in
   damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON
   splitting.

 - The series "memcg-v1: fully deprecate charge moving" from Shakeel
   Butt removes the long-deprecated memcgv2 charge moving feature.

 - The series "fix error handling in mmap_region() and refactor" from
   Lorenzo Stoakes cleanup up some of the mmap() error handling and
   addresses some potential performance issues.

 - The series "x86/module: use large ROX pages for text allocations"
   from Mike Rapoport teaches x86 to use large pages for
   read-only-execute module text.

 - The series "page allocation tag compression" from Suren Baghdasaryan
   is followon maintenance work for the new page allocation profiling
   feature.

 - The series "page->index removals in mm" from Matthew Wilcox remove
   most references to page->index in mm/. A slow march towards shrinking
   struct page.

 - The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs
   interface tests" from Andrew Paniakin performs maintenance work for
   DAMON's self testing code.

 - The series "mm: zswap swap-out of large folios" from Kanchana Sridhar
   improves zswap's batching of compression and decompression. It is a
   step along the way towards using Intel IAA hardware acceleration for
   this zswap operation.

 - The series "kasan: migrate the last module test to kunit" from
   Sabyrzhan Tasbolatov completes the migration of the KASAN built-in
   tests over to the KUnit framework.

 - The series "implement lightweight guard pages" from Lorenzo Stoakes
   permits userapace to place fault-generating guard pages within a
   single VMA, rather than requiring that multiple VMAs be created for
   this. Improved efficiencies for userspace memory allocators are
   expected.

 - The series "memcg: tracepoint for flushing stats" from JP Kobryn uses
   tracepoints to provide increased visibility into memcg stats flushing
   activity.

 - The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky
   fixes a zram buglet which potentially affected performance.

 - The series "mm: add more kernel parameters to control mTHP" from
   MaĆ­ra Canal enhances our ability to control/configuremultisize THP
   from the kernel boot command line.

 - The series "kasan: few improvements on kunit tests" from Sabyrzhan
   Tasbolatov has a couple of fixups for the KASAN KUnit tests.

 - The series "mm/list_lru: Split list_lru lock into per-cgroup scope"
   from Kairui Song optimizes list_lru memory utilization when lockdep
   is enabled.

* tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (215 commits)
  cma: enforce non-zero pageblock_order during cma_init_reserved_mem()
  mm/kfence: add a new kunit test test_use_after_free_read_nofault()
  zram: fix NULL pointer in comp_algorithm_show()
  memcg/hugetlb: add hugeTLB counters to memcg
  vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event
  mm: mmap_lock: check trace_mmap_lock_$type_enabled() instead of regcount
  zram: ZRAM_DEF_COMP should depend on ZRAM
  MAINTAINERS/MEMORY MANAGEMENT: add document files for mm
  Docs/mm/damon: recommend academic papers to read and/or cite
  mm: define general function pXd_init()
  kmemleak: iommu/iova: fix transient kmemleak false positive
  mm/list_lru: simplify the list_lru walk callback function
  mm/list_lru: split the lock to per-cgroup scope
  mm/list_lru: simplify reparenting and initial allocation
  mm/list_lru: code clean up for reparenting
  mm/list_lru: don't export list_lru_add
  mm/list_lru: don't pass unnecessary key parameters
  kasan: add kunit tests for kmalloc_track_caller, kmalloc_node_track_caller
  kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW
  kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols
  ...
2024-11-23 09:58:07 -08:00
Pankaj RaghavandAndrew Morton 0938b16146 mm: don't set readahead flag on a folio when lookahead_size > nr_to_read
The readahead flag is set on a folio based on the lookahead_size and
nr_to_read.  For example, when the readahead happens from index to index +
nr_to_read, then the readahead `mark` offset from index is set at
nr_to_read - lookahead_size.

There are some scenarios where the lookahead_size > nr_to_read.  For
example, readahead window was created, but the file was truncated before
the readahead starts.  do_page_cache_ra() will clamp the nr_to_read if the
readahead window extends beyond EOF after truncation.  If this happens,
readahead flag should not be set on any folio on the current readahead
window.

The current calculation for `mark` with mapping_min_order > 0 gives
incorrect results when lookahead_size > nr_to_read due to rounding up
operation:

index = 128
nr_to_read = 16
lookahead_size = 28
mapping_min_order = 4 (16 pages)

ra_folio_index = round_up(128 + 16 - 28, 16) = 128;
mark = 128 - 128 = 0; # offset from index to set RA flag

In the above example, the lookahead_size is actually lying outside the
current readahead window.  Without this patch, RA flag will be set
incorrectly on the folio at index 128.  This can lead to marking the
readahead flag on the wrong folio, therefore, triggering a readahead when
it is not necessary.

Explicitly initialize `mark` to be ULONG_MAX and only calculate it when
lookahead_size is within the readahead window.

Link: https://lkml.kernel.org/r/20241017062342.478973-1-kernel@pankajraghav.com
Fixes: 26cfdb395e ("readahead: allocate folios with mapping_min_order in readahead")
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-06 20:11:15 -08:00
Al Viro 6348be02ee fdget(), trivial conversions
fdget() is the first thing done in scope, all matching fdput() are
immediately followed by leaving the scope.

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-11-03 01:28:06 -05:00
Linus Torvalds f8ffbc365f Merge tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull 'struct fd' updates from Al Viro:
 "Just the 'struct fd' layout change, with conversion to accessor
  helpers"

* tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  add struct fd constructors, get rid of __to_fd()
  struct fd: representation change
  introduce fd_file(), convert all accessors to it.
2024-09-23 09:35:36 -07:00
Pankaj RaghavandChristian Brauner 26cfdb395e readahead: allocate folios with mapping_min_order in readahead
page_cache_ra_unbounded() was allocating single pages (0 order folios)
if there was no folio found in an index. Allocate mapping_min_order folios
as we need to guarantee the minimum order if it is set.

page_cache_ra_order() tries to allocate folio to the page cache with a
higher order if the index aligns with that order. Modify it so that the
order does not go below the mapping_min_order requirement of the page
cache. This function will do the right thing even if the new_order passed
is less than the mapping_min_order.
When adding new folios to the page cache we must also ensure the index
used is aligned to the mapping_min_order as the page cache requires the
index to be aligned to the order of the folio.

readahead_expand() is called from readahead aops to extend the range of
the readahead so this function can assume ractl->_index to be aligned with
min_order.

Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Co-developed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240822135018.1931258-4-kernel@pankajraghav.com
Tested-by: David Howells <dhowells@redhat.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Daniel Gomez <da.gomez@samsung.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-23 13:49:48 +02:00