Commit Graph

138 Commits

Author SHA1 Message Date
Linus Torvalds 98931dd95f Yang Shi has improved the behaviour of khugepaged collapsing of readonly
file-backed transparent hugepages.
 
 Johannes Weiner has arranged for zswap memory use to be tracked and
 managed on a per-cgroup basis.
 
 Munchun Song adds a /proc knob ("hugetlb_optimize_vmemmap") for runtime
 enablement of the recent huge page vmemmap optimization feature.
 
 Baolin Wang contributes a series to fix some issues around hugetlb
 pagetable invalidation.
 
 Zhenwei Pi has fixed some interactions between hwpoisoned pages and
 virtualization.
 
 Tong Tiangen has enabled the use of the presently x86-only
 page_table_check debugging feature on arm64 and riscv.
 
 David Vernet has done some fixup work on the memcg selftests.
 
 Peter Xu has taught userfaultfd to handle write protection faults against
 shmem- and hugetlbfs-backed files.
 
 More DAMON development from SeongJae Park - adding online tuning of the
 feature and support for monitoring of fixed virtual address ranges.  Also
 easier discovery of which monitoring operations are available.
 
 Nadav Amit has done some optimization of TLB flushing during mprotect().
 
 Neil Brown continues to labor away at improving our swap-over-NFS support.
 
 David Hildenbrand has some fixes to anon page COWing versus
 get_user_pages().
 
 Peng Liu fixed some errors in the core hugetlb code.
 
 Joao Martins has reduced the amount of memory consumed by device-dax's
 compound devmaps.
 
 Some cleanups of the arch-specific pagemap code from Anshuman Khandual.
 
 Muchun Song has found and fixed some errors in the TLB flushing of
 transparent hugepages.
 
 Roman Gushchin has done more work on the memcg selftests.
 
 And, of course, many smaller fixes and cleanups.  Notably, the customary
 million cleanup serieses from Miaohe Lin.
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Merge tag 'mm-stable-2022-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "Almost all of MM here. A few things are still getting finished off,
  reviewed, etc.

   - Yang Shi has improved the behaviour of khugepaged collapsing of
     readonly file-backed transparent hugepages.

   - Johannes Weiner has arranged for zswap memory use to be tracked and
     managed on a per-cgroup basis.

   - Munchun Song adds a /proc knob ("hugetlb_optimize_vmemmap") for
     runtime enablement of the recent huge page vmemmap optimization
     feature.

   - Baolin Wang contributes a series to fix some issues around hugetlb
     pagetable invalidation.

   - Zhenwei Pi has fixed some interactions between hwpoisoned pages and
     virtualization.

   - Tong Tiangen has enabled the use of the presently x86-only
     page_table_check debugging feature on arm64 and riscv.

   - David Vernet has done some fixup work on the memcg selftests.

   - Peter Xu has taught userfaultfd to handle write protection faults
     against shmem- and hugetlbfs-backed files.

   - More DAMON development from SeongJae Park - adding online tuning of
     the feature and support for monitoring of fixed virtual address
     ranges. Also easier discovery of which monitoring operations are
     available.

   - Nadav Amit has done some optimization of TLB flushing during
     mprotect().

   - Neil Brown continues to labor away at improving our swap-over-NFS
     support.

   - David Hildenbrand has some fixes to anon page COWing versus
     get_user_pages().

   - Peng Liu fixed some errors in the core hugetlb code.

   - Joao Martins has reduced the amount of memory consumed by
     device-dax's compound devmaps.

   - Some cleanups of the arch-specific pagemap code from Anshuman
     Khandual.

   - Muchun Song has found and fixed some errors in the TLB flushing of
     transparent hugepages.

   - Roman Gushchin has done more work on the memcg selftests.

  ... and, of course, many smaller fixes and cleanups. Notably, the
  customary million cleanup serieses from Miaohe Lin"

* tag 'mm-stable-2022-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (381 commits)
  mm: kfence: use PAGE_ALIGNED helper
  selftests: vm: add the "settings" file with timeout variable
  selftests: vm: add "test_hmm.sh" to TEST_FILES
  selftests: vm: check numa_available() before operating "merge_across_nodes" in ksm_tests
  selftests: vm: add migration to the .gitignore
  selftests/vm/pkeys: fix typo in comment
  ksm: fix typo in comment
  selftests: vm: add process_mrelease tests
  Revert "mm/vmscan: never demote for memcg reclaim"
  mm/kfence: print disabling or re-enabling message
  include/trace/events/percpu.h: cleanup for "percpu: improve percpu_alloc_percpu event trace"
  include/trace/events/mmflags.h: cleanup for "tracing: incorrect gfp_t conversion"
  mm: fix a potential infinite loop in start_isolate_page_range()
  MAINTAINERS: add Muchun as co-maintainer for HugeTLB
  zram: fix Kconfig dependency warning
  mm/shmem: fix shmem folio swapoff hang
  cgroup: fix an error handling path in alloc_pagecache_max_30M()
  mm: damon: use HPAGE_PMD_SIZE
  tracing: incorrect isolate_mote_t cast in mm_vmscan_lru_isolate
  nodemask.h: fix compilation error with GCC12
  ...
2022-05-26 12:32:41 -07:00
Linus Torvalds fdaf9a5840 Page cache changes for 5.19
- Appoint myself page cache maintainer
 
  - Fix how scsicam uses the page cache
 
  - Use the memalloc_nofs_save() API to replace AOP_FLAG_NOFS
 
  - Remove the AOP flags entirely
 
  - Remove pagecache_write_begin() and pagecache_write_end()
 
  - Documentation updates
 
  - Convert several address_space operations to use folios:
    - is_dirty_writeback
    - readpage becomes read_folio
    - releasepage becomes release_folio
    - freepage becomes free_folio
 
  - Change filler_t to require a struct file pointer be the first argument
    like ->read_folio
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Merge tag 'folio-5.19' of git://git.infradead.org/users/willy/pagecache

Pull page cache updates from Matthew Wilcox:

 - Appoint myself page cache maintainer

 - Fix how scsicam uses the page cache

 - Use the memalloc_nofs_save() API to replace AOP_FLAG_NOFS

 - Remove the AOP flags entirely

 - Remove pagecache_write_begin() and pagecache_write_end()

 - Documentation updates

 - Convert several address_space operations to use folios:
     - is_dirty_writeback
     - readpage becomes read_folio
     - releasepage becomes release_folio
     - freepage becomes free_folio

 - Change filler_t to require a struct file pointer be the first
   argument like ->read_folio

* tag 'folio-5.19' of git://git.infradead.org/users/willy/pagecache: (107 commits)
  nilfs2: Fix some kernel-doc comments
  Appoint myself page cache maintainer
  fs: Remove aops->freepage
  secretmem: Convert to free_folio
  nfs: Convert to free_folio
  orangefs: Convert to free_folio
  fs: Add free_folio address space operation
  fs: Convert drop_buffers() to use a folio
  fs: Change try_to_free_buffers() to take a folio
  jbd2: Convert release_buffer_page() to use a folio
  jbd2: Convert jbd2_journal_try_to_free_buffers to take a folio
  reiserfs: Convert release_buffer_page() to use a folio
  fs: Remove last vestiges of releasepage
  ubifs: Convert to release_folio
  reiserfs: Convert to release_folio
  orangefs: Convert to release_folio
  ocfs2: Convert to release_folio
  nilfs2: Remove comment about releasepage
  nfs: Convert to release_folio
  jfs: Convert to release_folio
  ...
2022-05-24 19:55:07 -07:00
NeilBrown 6341a446a0 MM: handle THP in swap_*page_fs() - count_vm_events()
We need to use count_swpout_vm_event() for sio_write_complete() to get
correct counting.

Note that THP swap in (if it ever happens) is current accounted 1 for each
page, whether HUGE or normal.  This is different from swap-out accounting.

This patch should be squashed into
    MM: handle THP in swap_*page_fs()

Link: https://lkml.kernel.org/r/165146948934.24404.5909750610552745025@noble.neil.brown.name
Signed-off-by: NeilBrown <neilb@suse.de>
Reported-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-09 18:20:49 -07:00
NeilBrown a1a0dfd56f mm: handle THP in swap_*page_fs()
Pages passed to swap_readpage()/swap_writepage() are not necessarily all
the same size - there may be transparent-huge-pages involves.

The BIO paths of swap_*page() handle this correctly, but the SWP_FS_OPS
path does not.

So we need to use thp_size() to find the size, not just assume PAGE_SIZE,
and we need to track the total length of the request, not just assume it
is "page * PAGE_SIZE".

Link: https://lkml.kernel.org/r/165119301488.15698.9457662928942765453.stgit@noble.brown
Signed-off-by: NeilBrown <neilb@suse.de>
Reported-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-09 18:20:49 -07:00
NeilBrown 2282679fb2 mm: submit multipage write for SWP_FS_OPS swap-space
swap_writepage() is given one page at a time, but may be called repeatedly
in succession.

For block-device swapspace, the blk_plug functionality allows the multiple
pages to be combined together at lower layers.  That cannot be used for
SWP_FS_OPS as blk_plug may not exist - it is only active when
CONFIG_BLOCK=y.  Consequently all swap reads over NFS are single page
reads.

With this patch we pass a pointer-to-pointer via the wbc.  swap_writepage
can store state between calls - much like the pointer passed explicitly to
swap_readpage.  After calling swap_writepage() some number of times, the
state will be passed to swap_write_unplug() which can submit the combined
request.

Link: https://lkml.kernel.org/r/164859778128.29473.5191868522654408537.stgit@noble.brown
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: David Howells <dhowells@redhat.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-09 18:20:49 -07:00
NeilBrown 5169b844b7 mm: submit multipage reads for SWP_FS_OPS swap-space
swap_readpage() is given one page at a time, but may be called repeatedly
in succession.

For block-device swap-space, the blk_plug functionality allows the
multiple pages to be combined together at lower layers.  That cannot be
used for SWP_FS_OPS as blk_plug may not exist - it is only active when
CONFIG_BLOCK=y.  Consequently all swap reads over NFS are single page
reads.

With this patch we pass in a pointer-to-pointer when swap_readpage can
store state between calls - much like the effect of blk_plug.  After
calling swap_readpage() some number of times, the state will be passed to
swap_read_unplug() which can submit the combined request.

Link: https://lkml.kernel.org/r/164859778127.29473.14059420492644907783.stgit@noble.brown
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: David Howells <dhowells@redhat.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-09 18:20:49 -07:00
NeilBrown 7eadabc05d mm: perform async writes to SWP_FS_OPS swap-space using ->swap_rw
This patch switches swap-out to SWP_FS_OPS swap-spaces to use ->swap_rw
and makes the writes asynchronous, like they are for other swap spaces.

To make it async we need to allocate the kiocb struct from a mempool. 
This may block, but won't block as long as waiting for the write to
complete.  At most it will wait for some previous swap IO to complete.

Link: https://lkml.kernel.org/r/164859778126.29473.12399585304843922231.stgit@noble.brown
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: David Howells <dhowells@redhat.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-09 18:20:48 -07:00
NeilBrown e1209d3a7a mm: introduce ->swap_rw and use it for reads from SWP_FS_OPS swap-space
swap currently uses ->readpage to read swap pages.  This can only request
one page at a time from the filesystem, which is not most efficient.

swap uses ->direct_IO for writes which while this is adequate is an
inappropriate over-loading.  ->direct_IO may need to had handle allocate
space for holes or other details that are not relevant for swap.

So this patch introduces a new address_space operation: ->swap_rw.  In
this patch it is used for reads, and a subsequent patch will switch writes
to use it.

No filesystem yet supports ->swap_rw, but that is not a problem because
no filesystem actually works with filesystem-based swap.
Only two filesystems set SWP_FS_OPS:
- cifs sets the flag, but ->direct_IO always fails so swap cannot work.
- nfs sets the flag, but ->direct_IO calls generic_write_checks()
  which has failed on swap files for several releases.

To ensure that a NULL ->swap_rw isn't called, ->activate_swap() for both
NFS and cifs are changed to fail if ->swap_rw is not set.  This can be
removed if/when the function is added.

Future patches will restore swap-over-NFS functionality.

To submit an async read with ->swap_rw() we need to allocate a structure
to hold the kiocb and other details.  swap_readpage() cannot handle
transient failure, so we create a mempool to provide the structures.

Link: https://lkml.kernel.org/r/164859778125.29473.13430559328221330589.stgit@noble.brown
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: David Howells <dhowells@redhat.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-09 18:20:48 -07:00
NeilBrown 4c4a763406 mm: drop swap_dirty_folio
folios that are written to swap are owned by the MM subsystem - not any
filesystem.

When such a folio is passed to a filesystem to be written out to a
swap-file, the filesystem handles the data, but the folio itself does not
belong to the filesystem.  So calling the filesystem's ->dirty_folio()
address_space operation makes no sense.  This is for folios in the given
address space, and a folio to be written to swap does not exist in the
given address space.

So drop swap_dirty_folio() which calls the address-space's
->dirty_folio(), and always use noop_dirty_folio(), which is appropriate
for folios being swapped out.

Link: https://lkml.kernel.org/r/164859778123.29473.6900942583784889976.stgit@noble.brown
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: David Howells <dhowells@redhat.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-09 18:20:47 -07:00
NeilBrown 014bb1de4f mm: create new mm/swap.h header file
Patch series "MM changes to improve swap-over-NFS support".

Assorted improvements for swap-via-filesystem.

This is a resend of these patches, rebased on current HEAD.  The only
substantial changes is that swap_dirty_folio has replaced
swap_set_page_dirty.

Currently swap-via-fs (SWP_FS_OPS) doesn't work for any filesystem.  It
has previously worked for NFS but that broke a few releases back.  This
series changes to use a new ->swap_rw rather than ->readpage and
->direct_IO.  It also makes other improvements.

There is a companion series already in linux-next which fixes various
issues with NFS.  Once both series land, a final patch is needed which
changes NFS over to use ->swap_rw.


This patch (of 10):

Many functions declared in include/linux/swap.h are only used within mm/

Create a new "mm/swap.h" and move some of these declarations there.
Remove the redundant 'extern' from the function declarations.

[akpm@linux-foundation.org: mm/memory-failure.c needs mm/swap.h]
Link: https://lkml.kernel.org/r/164859751830.29473.5309689752169286816.stgit@noble.brown
Link: https://lkml.kernel.org/r/164859778120.29473.11725907882296224053.stgit@noble.brown
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: David Howells <dhowells@redhat.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-09 18:20:47 -07:00
Matthew Wilcox (Oracle) 0f312591d6 mm: Convert swap_readpage to call read_folio instead of readpage
This commit is split out so it can be dropped when resolving
conflicts with Neil Brown's series to stop calling ->readpage in
the swap code.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-05-09 16:21:46 -04:00
Ming Lei 9650b453a3 block: ignore RWF_HIPRI hint for sync dio
So far bio is marked as REQ_POLLED if RWF_HIPRI/IOCB_HIPRI is passed
from userspace sync io interface, then block layer tries to poll until
the bio is completed. But the current implementation calls
blk_io_schedule() if bio_poll() returns 0, and this way causes io hang or
timeout easily.

But looks no one reports this kind of issue, which should have been
triggered in normal io poll sanity test or blktests block/007 as
observed by Changhui, that means it is very likely that no one uses it
or no one cares it.

Also after io_uring is invented, io poll for sync dio becomes legacy
interface.

So ignore RWF_HIPRI hint for sync dio.

CC: linux-mm@kvack.org
Cc: linux-xfs@vger.kernel.org
Reported-by: Changhui Zhong <czhong@redhat.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Changhui Zhong <czhong@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220420143110.2679002-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-05-02 10:07:42 -06:00
Minchan Kim e914d8f003 mm: fix unexpected zeroed page mapping with zram swap
Two processes under CLONE_VM cloning, user process can be corrupted by
seeing zeroed page unexpectedly.

      CPU A                        CPU B

  do_swap_page                do_swap_page
  SWP_SYNCHRONOUS_IO path     SWP_SYNCHRONOUS_IO path
  swap_readpage valid data
    swap_slot_free_notify
      delete zram entry
                              swap_readpage zeroed(invalid) data
                              pte_lock
                              map the *zero data* to userspace
                              pte_unlock
  pte_lock
  if (!pte_same)
    goto out_nomap;
  pte_unlock
  return and next refault will
  read zeroed data

The swap_slot_free_notify is bogus for CLONE_VM case since it doesn't
increase the refcount of swap slot at copy_mm so it couldn't catch up
whether it's safe or not to discard data from backing device.  In the
case, only the lock it could rely on to synchronize swap slot freeing is
page table lock.  Thus, this patch gets rid of the swap_slot_free_notify
function.  With this patch, CPU A will see correct data.

      CPU A                        CPU B

  do_swap_page                do_swap_page
  SWP_SYNCHRONOUS_IO path     SWP_SYNCHRONOUS_IO path
                              swap_readpage original data
                              pte_lock
                              map the original data
                              swap_free
                                swap_range_free
                                  bd_disk->fops->swap_slot_free_notify
  swap_readpage read zeroed data
                              pte_unlock
  pte_lock
  if (!pte_same)
    goto out_nomap;
  pte_unlock
  return
  on next refault will see mapped data by CPU B

The concern of the patch would increase memory consumption since it
could keep wasted memory with compressed form in zram as well as
uncompressed form in address space.  However, most of cases of zram uses
no readahead and do_swap_page is followed by swap_free so it will free
the compressed form from in zram quickly.

Link: https://lkml.kernel.org/r/YjTVVxIAsnKAXjTd@google.com
Fixes: 0bcac06f27 ("mm, swap: skip swapcache for swapin of synchronous device")
Reported-by: Ivan Babrou <ivan@cloudflare.com>
Tested-by: Ivan Babrou <ivan@cloudflare.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: David Hildenbrand <david@redhat.com>
Cc: <stable@vger.kernel.org>	[4.14+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-04-15 14:49:55 -07:00
Linus Torvalds 6b1f86f8e9 Filesystem folio changes for 5.18
Primarily this series converts some of the address_space operations
 to take a folio instead of a page.
 
 ->is_partially_uptodate() takes a folio instead of a page and changes the
 type of the 'from' and 'count' arguments to make it obvious they're bytes.
 ->invalidatepage() becomes ->invalidate_folio() and has a similar type change.
 ->launder_page() becomes ->launder_folio()
 ->set_page_dirty() becomes ->dirty_folio() and adds the address_space as
 an argument.
 
 There are a couple of other misc changes up front that weren't worth
 separating into their own pull request.
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Merge tag 'folio-5.18b' of git://git.infradead.org/users/willy/pagecache

Pull filesystem folio updates from Matthew Wilcox:
 "Primarily this series converts some of the address_space operations to
  take a folio instead of a page.

  Notably:

   - a_ops->is_partially_uptodate() takes a folio instead of a page and
     changes the type of the 'from' and 'count' arguments to make it
     obvious they're bytes.

   - a_ops->invalidatepage() becomes ->invalidate_folio() and has a
     similar type change.

   - a_ops->launder_page() becomes ->launder_folio()

   - a_ops->set_page_dirty() becomes ->dirty_folio() and adds the
     address_space as an argument.

  There are a couple of other misc changes up front that weren't worth
  separating into their own pull request"

* tag 'folio-5.18b' of git://git.infradead.org/users/willy/pagecache: (53 commits)
  fs: Remove aops ->set_page_dirty
  fb_defio: Use noop_dirty_folio()
  fs: Convert __set_page_dirty_no_writeback to noop_dirty_folio
  fs: Convert __set_page_dirty_buffers to block_dirty_folio
  nilfs: Convert nilfs_set_page_dirty() to nilfs_dirty_folio()
  mm: Convert swap_set_page_dirty() to swap_dirty_folio()
  ubifs: Convert ubifs_set_page_dirty to ubifs_dirty_folio
  f2fs: Convert f2fs_set_node_page_dirty to f2fs_dirty_node_folio
  f2fs: Convert f2fs_set_data_page_dirty to f2fs_dirty_data_folio
  f2fs: Convert f2fs_set_meta_page_dirty to f2fs_dirty_meta_folio
  afs: Convert afs_dir_set_page_dirty() to afs_dir_dirty_folio()
  btrfs: Convert extent_range_redirty_for_io() to use folios
  fs: Convert trivial uses of __set_page_dirty_nobuffers to filemap_dirty_folio
  btrfs: Convert from set_page_dirty to dirty_folio
  fscache: Convert fscache_set_page_dirty() to fscache_dirty_folio()
  fs: Add aops->dirty_folio
  fs: Remove aops->launder_page
  orangefs: Convert launder_page to launder_folio
  nfs: Convert from launder_page to launder_folio
  fuse: Convert from launder_page to launder_folio
  ...
2022-03-22 18:26:56 -07:00
Linus Torvalds 3bf03b9a08 Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton:

 - A few misc subsystems: kthread, scripts, ntfs, ocfs2, block, and vfs

 - Most the MM patches which precede the patches in Willy's tree: kasan,
   pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap,
   sparsemem, vmalloc, pagealloc, memory-failure, mlock, hugetlb,
   userfaultfd, vmscan, compaction, mempolicy, oom-kill, migration, thp,
   cma, autonuma, psi, ksm, page-poison, madvise, memory-hotplug, rmap,
   zswap, uaccess, ioremap, highmem, cleanups, kfence, hmm, and damon.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (227 commits)
  mm/damon/sysfs: remove repeat container_of() in damon_sysfs_kdamond_release()
  Docs/ABI/testing: add DAMON sysfs interface ABI document
  Docs/admin-guide/mm/damon/usage: document DAMON sysfs interface
  selftests/damon: add a test for DAMON sysfs interface
  mm/damon/sysfs: support DAMOS stats
  mm/damon/sysfs: support DAMOS watermarks
  mm/damon/sysfs: support schemes prioritization
  mm/damon/sysfs: support DAMOS quotas
  mm/damon/sysfs: support DAMON-based Operation Schemes
  mm/damon/sysfs: support the physical address space monitoring
  mm/damon/sysfs: link DAMON for virtual address spaces monitoring
  mm/damon: implement a minimal stub for sysfs-based DAMON interface
  mm/damon/core: add number of each enum type values
  mm/damon/core: allow non-exclusive DAMON start/stop
  Docs/damon: update outdated term 'regions update interval'
  Docs/vm/damon/design: update DAMON-Idle Page Tracking interference handling
  Docs/vm/damon: call low level monitoring primitives the operations
  mm/damon: remove unnecessary CONFIG_DAMON option
  mm/damon/paddr,vaddr: remove damon_{p,v}a_{target_valid,set_operations}()
  mm/damon/dbgfs-test: fix is_target_id() change
  ...
2022-03-22 16:11:53 -07:00
Johannes Weiner d8c47cc7bf mm: page_io: fix psi memory pressure error on cold swapins
Once upon a time, all swapins counted toward memory pressure[1].  Then
Joonsoo introduced workingset detection for anonymous pages and we gained
the ability to distinguish hot from cold swapins[2][3].  But we failed to
update swap_readpage() accordingly, and now we account partial memory
pressure in the swapin path of cold memory.

Not for all situations - which adds more inconsistency: paths using the
conventional submit_bio() and lock_page() route will not see much pressure
- unless storage itself is heavily congested and the bio submissions
stall.  ZRAM and ZSWAP do most of the work directly from swap_readpage()
and will see all swapins reflected as pressure.

IOW, a workload doing cold swapins could see little to no pressure
reported with on-disk swap, but potentially high pressure with a zram or
zswap backend.  That confuses any psi-based health monitoring, load
shedding, proactive reclaim, or userspace OOM killing schemes that might
be in place for the workload.

Restore consistency by making all swapin stall accounting conditional on
the page actually being part of the workingset.

[1] commit 937790699b ("mm/page_io.c: annotate refault stalls from swap_readpage")
[2] commit aae466b005 ("mm/swap: implement workingset detection for anonymous LRU")
[3] commit cad8320b4b ("mm/swap: don't SetPageWorkingset unconditionally during swapin")

Link: https://lkml.kernel.org/r/20220214214921.419687-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: CGEL <cgel.zte@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22 15:57:09 -07:00
Matthew Wilcox (Oracle) 3a3bae50af fs: Remove aops ->set_page_dirty
With all implementations converted to ->dirty_folio, we can stop calling
this fallback method and remove it entirely.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs
Tested-by: David Howells <dhowells@redhat.com> # afs
2022-03-16 13:37:05 -04:00
Matthew Wilcox (Oracle) 46de8b9794 fs: Convert __set_page_dirty_no_writeback to noop_dirty_folio
This is a mechanical change.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs
Tested-by: David Howells <dhowells@redhat.com> # afs
2022-03-16 13:37:05 -04:00
Matthew Wilcox (Oracle) 7e63df00cf mm: Convert swap_set_page_dirty() to swap_dirty_folio()
Straightforward conversion.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs
Tested-by: David Howells <dhowells@redhat.com> # afs
2022-03-15 08:34:38 -04:00
Matthew Wilcox (Oracle) 6f31a5a261 fs: Add aops->dirty_folio
This replaces ->set_page_dirty().  It returns a bool instead of an int
and takes the address_space as a parameter instead of expecting the
implementations to retrieve the address_space from the page.  This is
particularly important for filesystems which use FS_OPS for swap.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs
Tested-by: David Howells <dhowells@redhat.com> # afs
2022-03-15 08:23:30 -04:00
Christoph Hellwig 07888c665b block: pass a block_device and opf to bio_alloc
Pass the block_device and operation that we plan to use this bio for to
bio_alloc to optimize the assignment.  NULL/0 can be passed, both for the
passthrough case on a raw request_queue and to temporarily avoid
refactoring some nasty code.

Also move the gfp_mask argument after the nr_vecs argument for a much
more logical calling convention matching what most of the kernel does.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-18-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-02 07:49:59 -07:00
Yang Yang a3d5dc908a delayacct: support swapin delay accounting for swapping without blkio
Currently delayacct accounts swapin delay only for swapping that cause
blkio.  If we use zram for swapping, tools/accounting/getdelays can't
get any SWAP delay.

It's useful to get zram swapin delay information, for example to adjust
compress algorithm or /proc/sys/vm/swappiness.

Reference to PSI, it accounts any kind of swapping by doing its work in
swap_readpage(), no matter whether swapping causes blkio.  Let delayacct
do the similar work.

Link: https://lkml.kernel.org/r/20211112083813.8559-1-yang.yang29@zte.com.cn
Signed-off-by: Yang Yang <yang.yang29@zte.com.cn>
Reported-by: Zeal Robot <zealci@zte.com.cn>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-20 08:52:55 +02:00
Linus Torvalds 33c8846c81 for-5.16/block-2021-10-29
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Merge tag 'for-5.16/block-2021-10-29' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:

 - mq-deadline accounting improvements (Bart)

 - blk-wbt timer fix (Andrea)

 - Untangle the block layer includes (Christoph)

 - Rework the poll support to be bio based, which will enable adding
   support for polling for bio based drivers (Christoph)

 - Block layer core support for multi-actuator drives (Damien)

 - blk-crypto improvements (Eric)

 - Batched tag allocation support (me)

 - Request completion batching support (me)

 - Plugging improvements (me)

 - Shared tag set improvements (John)

 - Concurrent queue quiesce support (Ming)

 - Cache bdev in ->private_data for block devices (Pavel)

 - bdev dio improvements (Pavel)

 - Block device invalidation and block size improvements (Xie)

 - Various cleanups, fixes, and improvements (Christoph, Jackie,
   Masahira, Tejun, Yu, Pavel, Zheng, me)

* tag 'for-5.16/block-2021-10-29' of git://git.kernel.dk/linux-block: (174 commits)
  blk-mq-debugfs: Show active requests per queue for shared tags
  block: improve readability of blk_mq_end_request_batch()
  virtio-blk: Use blk_validate_block_size() to validate block size
  loop: Use blk_validate_block_size() to validate block size
  nbd: Use blk_validate_block_size() to validate block size
  block: Add a helper to validate the block size
  block: re-flow blk_mq_rq_ctx_init()
  block: prefetch request to be initialized
  block: pass in blk_mq_tags to blk_mq_rq_ctx_init()
  block: add rq_flags to struct blk_mq_alloc_data
  block: add async version of bio_set_polled
  block: kill DIO_MULTI_BIO
  block: kill unused polling bits in __blkdev_direct_IO()
  block: avoid extra iter advance with async iocb
  block: Add independent access ranges support
  blk-mq: don't issue request directly in case that current is to be blocked
  sbitmap: silence data race warning
  blk-cgroup: synchronize blkg creation against policy deactivation
  block: refactor bio_iov_bvec_set()
  block: add single bio async direct IO helper
  ...
2021-11-01 09:19:50 -07:00
Jens Axboe 5a72e899ce block: add a struct io_comp_batch argument to fops->iopoll()
struct io_comp_batch contains a list head and a completion handler, which
will allow completions to more effciently completed batches of IO.

For now, no functional changes in this patch, we just define the
io_comp_batch structure and add the argument to the file_operations iopoll
handler.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18 14:40:40 -06:00
Christoph Hellwig 3e08773c38 block: switch polling to be bio based
Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.

Polling for the bio itself leads to a few advantages:

 - the cookie construction can made entirely private in blk-mq.c
 - the caller does not need to remember the request_queue and cookie
   separately and thus sidesteps their lifetime issues
 - keeping the device and the cookie inside the bio allows to trivially
   support polling BIOs remapping by stacking drivers
 - a lot of code to propagate the cookie back up the submission path can
   be removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18 06:17:36 -06:00
Christoph Hellwig 6ce913fe3e block: rename REQ_HIPRI to REQ_POLLED
Unlike the RWF_HIPRI userspace ABI which is intentionally kept vague,
the bio flag is specific to the polling implementation, so rename and
document it properly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-12-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18 06:17:36 -06:00
Christoph Hellwig ef99b2d376 block: replace the spin argument to blk_iopoll with a flags argument
Switch the boolean spin argument to blk_poll to passing a set of flags
instead.  This will allow to control polling behavior in a more fine
grained way.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-10-hch@lst.de
[axboe: adapt to changed io_uring iopoll]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18 06:17:36 -06:00
Matthew Wilcox (Oracle) 575ced1c8b mm/swap: Add folio_rotate_reclaimable()
Convert rotate_reclaimable_page() to folio_rotate_reclaimable().  This
eliminates all five of the calls to compound_head() in this function,
saving 75 bytes at the cost of adding 15 bytes to its one caller,
end_page_writeback().  We also save 36 bytes from pagevec_move_tail_fn()
due to using folios there.  Net 96 bytes savings.

Also move its declaration to mm/internal.h as it's only used by filemap.c.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: David Howells <dhowells@redhat.com>
2021-09-27 09:27:30 -04:00
Jens Axboe caf6912f3f swap: fix swapfile read/write offset
We're not factoring in the start of the file for where to write and
read the swapfile, which leads to very unfortunate side effects of
writing where we should not be...

Fixes: 48d15436fd ("mm: remove get_swap_bio")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-02 17:25:46 -07:00
Georgi Djakov 25eaab438d mm/page_io: use pr_alert_ratelimited for swap read/write errors
If there are errors during swap read or write, they can easily fill the
log buffer and remove any previous messages that might be useful for
debugging, especially on systems that rely for logging only on the kernel
ring-buffer.

For example, on a systems using zram as swap, we are more likely to see
any page allocation errors preceding the swap write errors if the alerts
are ratelimited.

Link: https://lkml.kernel.org/r/20210201142055.29068-1-georgi.djakov@linaro.org
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:29 -08:00
Christoph Hellwig 48d15436fd mm: remove get_swap_bio
Just reuse the block_device and sector from the swap_info structure,
just as used by the SWP_SYNCHRONOUS path.  Also remove the checks for
NULL returns from bio_alloc as that can't happen for sleeping
allocations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-01-27 09:51:49 -07:00
Christoph Hellwig 309dca309f block: store a block_device pointer in struct bio
Replace the gendisk pointer in struct bio with a pointer to the newly
improved struct block device.  From that the gendisk can be trivially
accessed with an extra indirection, but it also allows to directly
look up all information related to partition remapping.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-01-24 18:17:20 -07:00
Roman Gushchin bcfe06bf26 mm: memcontrol: Use helpers to read page's memcg data
Patch series "mm: allow mapping accounted kernel pages to userspace", v6.

Currently a non-slab kernel page which has been charged to a memory cgroup
can't be mapped to userspace.  The underlying reason is simple: PageKmemcg
flag is defined as a page type (like buddy, offline, etc), so it takes a
bit from a page->mapped counter.  Pages with a type set can't be mapped to
userspace.

But in general the kmemcg flag has nothing to do with mapping to
userspace.  It only means that the page has been accounted by the page
allocator, so it has to be properly uncharged on release.

Some bpf maps are mapping the vmalloc-based memory to userspace, and their
memory can't be accounted because of this implementation detail.

This patchset removes this limitation by moving the PageKmemcg flag into
one of the free bits of the page->mem_cgroup pointer.  Also it formalizes
accesses to the page->mem_cgroup and page->obj_cgroups using new helpers,
adds several checks and removes a couple of obsolete functions.  As the
result the code became more robust with fewer open-coded bit tricks.

This patch (of 4):

Currently there are many open-coded reads of the page->mem_cgroup pointer,
as well as a couple of read helpers, which are barely used.

It creates an obstacle on a way to reuse some bits of the pointer for
storing additional bits of information.  In fact, we already do this for
slab pages, where the last bit indicates that a pointer has an attached
vector of objcg pointers instead of a regular memcg pointer.

This commits uses 2 existing helpers and introduces a new helper to
converts all read sides to calls of these helpers:
  struct mem_cgroup *page_memcg(struct page *page);
  struct mem_cgroup *page_memcg_rcu(struct page *page);
  struct mem_cgroup *page_memcg_check(struct page *page);

page_memcg_check() is intended to be used in cases when the page can be a
slab page and have a memcg pointer pointing at objcg vector.  It does
check the lowest bit, and if set, returns NULL.  page_memcg() contains a
VM_BUG_ON_PAGE() check for the page not being a slab page.

To make sure nobody uses a direct access, struct page's
mem_cgroup/obj_cgroups is converted to unsigned long memcg_data.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Link: https://lkml.kernel.org/r/20201027001657.3398190-1-guro@fb.com
Link: https://lkml.kernel.org/r/20201027001657.3398190-2-guro@fb.com
Link: https://lore.kernel.org/bpf/20201201215900.3569844-2-guro@fb.com
2020-12-02 18:28:05 -08:00
Miaohe Lin 548d9782bd mm/page_io.c: remove useless out label in __swap_writepage()
The out label is only used in one place and return ret directly without
something like resource cleanup or lock release and so on.  So we should
remove this jump label and do some cleanup.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20200927124032.22521-1-linmiaohe@huawei.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:30 -07:00
Gao Xiang 3264631548 swap: rename SWP_FS to SWAP_FS_OPS to avoid ambiguity
SWP_FS is used to make swap_{read,write}page() go through the filesystem,
and it's only used for swap files over NFS for now.  Otherwise it will
directly submit IO to blockdev according to swapfile extents reported by
filesystems in advance.

As Matthew pointed out [1], SWP_FS naming is somewhat confusing, so let's
rename to SWP_FS_OPS.

[1] https://lore.kernel.org/r/20200820113448.GM17456@casper.infradead.org

Suggested-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20200822113019.11319-1-hsiangkao@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:29 -07:00
Linus Torvalds 3ad11d7ac8 block-5.10-2020-10-12
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Merge tag 'block-5.10-2020-10-12' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:

 - Series of merge handling cleanups (Baolin, Christoph)

 - Series of blk-throttle fixes and cleanups (Baolin)

 - Series cleaning up BDI, seperating the block device from the
   backing_dev_info (Christoph)

 - Removal of bdget() as a generic API (Christoph)

 - Removal of blkdev_get() as a generic API (Christoph)

 - Cleanup of is-partition checks (Christoph)

 - Series reworking disk revalidation (Christoph)

 - Series cleaning up bio flags (Christoph)

 - bio crypt fixes (Eric)

 - IO stats inflight tweak (Gabriel)

 - blk-mq tags fixes (Hannes)

 - Buffer invalidation fixes (Jan)

 - Allow soft limits for zone append (Johannes)

 - Shared tag set improvements (John, Kashyap)

 - Allow IOPRIO_CLASS_RT for CAP_SYS_NICE (Khazhismel)

 - DM no-wait support (Mike, Konstantin)

 - Request allocation improvements (Ming)

 - Allow md/dm/bcache to use IO stat helpers (Song)

 - Series improving blk-iocost (Tejun)

 - Various cleanups (Geert, Damien, Danny, Julia, Tetsuo, Tian, Wang,
   Xianting, Yang, Yufen, yangerkun)

* tag 'block-5.10-2020-10-12' of git://git.kernel.dk/linux-block: (191 commits)
  block: fix uapi blkzoned.h comments
  blk-mq: move cancel of hctx->run_work to the front of blk_exit_queue
  blk-mq: get rid of the dead flush handle code path
  block: get rid of unnecessary local variable
  block: fix comment and add lockdep assert
  blk-mq: use helper function to test hw stopped
  block: use helper function to test queue register
  block: remove redundant mq check
  block: invoke blk_mq_exit_sched no matter whether have .exit_sched
  percpu_ref: don't refer to ref->data if it isn't allocated
  block: ratelimit handle_bad_sector() message
  blk-throttle: Re-use the throtl_set_slice_end()
  blk-throttle: Open code __throtl_de/enqueue_tg()
  blk-throttle: Move service tree validation out of the throtl_rb_first()
  blk-throttle: Move the list operation after list validation
  blk-throttle: Fix IO hang for a corner case
  blk-throttle: Avoid tracking latency if low limit is invalid
  blk-throttle: Avoid getting the current time if tg->last_finish_time is 0
  blk-throttle: Remove a meaningless parameter for throtl_downgrade_state()
  block: Remove redundant 'return' statement
  ...
2020-10-13 12:12:44 -07:00
Christoph Hellwig 5115db10a8 mm: use SWP_SYNCHRONOUS_IO more intelligently
There is no point in trying to call bdev_read_page if SWP_SYNCHRONOUS_IO
is not set, as the device won't support it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-24 13:43:39 -06:00
Steven Price 8a84802e2a mm: Add arch hooks for saving/restoring tags
Arm's Memory Tagging Extension (MTE) adds some metadata (tags) to
every physical page, when swapping pages out to disk it is necessary to
save these tags, and later restore them when reading the pages back.

Add some hooks along with dummy implementations to enable the
arch code to handle this.

Three new hooks are added to the swap code:
 * arch_prepare_to_swap() and
 * arch_swap_invalidate_page() / arch_swap_invalidate_area().
One new hook is added to shmem:
 * arch_swap_restore()

Signed-off-by: Steven Price <steven.price@arm.com>
[catalin.marinas@arm.com: add unlock_page() on the error path]
[catalin.marinas@arm.com: dropped the _tags suffix]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
2020-09-04 12:46:07 +01:00
Qian Cai 7b37e22675 mm/page_io: mark various intentional data races
struct swap_info_struct si.flags could be accessed concurrently as noticed
by KCSAN,

 BUG: KCSAN: data-race in scan_swap_map_slots / swap_readpage

 write to 0xffff9c77b80ac400 of 8 bytes by task 91325 on cpu 16:
  scan_swap_map_slots+0x6fe/0xb50
  scan_swap_map_slots at mm/swapfile.c:887
  get_swap_pages+0x39d/0x5c0
  get_swap_page+0x377/0x524
  add_to_swap+0xe4/0x1c0
  shrink_page_list+0x1740/0x2820
  shrink_inactive_list+0x316/0x8b0
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290
  __alloc_pages_nodemask+0x3bb/0x450
  alloc_pages_vma+0x8a/0x2c0
  do_anonymous_page+0x170/0x700
  __handle_mm_fault+0xc9f/0xd00
  handle_mm_fault+0xfc/0x2f0
  do_page_fault+0x263/0x6f9
  page_fault+0x34/0x40

 read to 0xffff9c77b80ac400 of 8 bytes by task 5422 on cpu 7:
  swap_readpage+0x204/0x6a0
  swap_readpage at mm/page_io.c:380
  read_swap_cache_async+0xa2/0xb0
  swapin_readahead+0x6a0/0x890
  do_swap_page+0x465/0xeb0
  __handle_mm_fault+0xc7a/0xd00
  handle_mm_fault+0xfc/0x2f0
  do_page_fault+0x263/0x6f9
  page_fault+0x34/0x40

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 7 PID: 5422 Comm: gmain Tainted: G        W  O L 5.5.0-next-20200204+ #6
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019

Other reads,

 read to 0xffff91ea33eac400 of 8 bytes by task 11276 on cpu 120:
  __swap_writepage+0x140/0xc20
  __swap_writepage at mm/page_io.c:289

 read to 0xffff91ea33eac400 of 8 bytes by task 11264 on cpu 16:
  swap_set_page_dirty+0x44/0x1f4
  swap_set_page_dirty at mm/page_io.c:442

The write is under &si->lock, but the reads are done as lockless.  Since
the reads only check for a specific bit in the flag, it is harmless even
if load tearing happens.  Thus, just mark them as intentional data races
using the data_race() macro.

[cai@lca.pw: add a missing annotation]
  Link: http://lkml.kernel.org/r/1581612585-5812-1-git-send-email-cai@lca.pw

Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Marco Elver <elver@google.com>
Link: http://lkml.kernel.org/r/20200207003601.1526-1-cai@lca.pw
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-14 19:56:56 -07:00
Matthew Wilcox (Oracle) 6c357848b4 mm: replace hpage_nr_pages with thp_nr_pages
The thp prefix is more frequently used than hpage and we should be
consistent between the various functions.

[akpm@linux-foundation.org: fix mm/migrate.c]

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Link: http://lkml.kernel.org/r/20200629151959.15779-6-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-14 19:56:56 -07:00
Matthew Wilcox (Oracle) af3bbc12df mm: add thp_size
This function returns the number of bytes in a THP.  It is like
page_size(), but compiles to just PAGE_SIZE if CONFIG_TRANSPARENT_HUGEPAGE
is disabled.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Link: http://lkml.kernel.org/r/20200629151959.15779-5-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-14 19:56:56 -07:00
Xianting Tian 0f190a7ab7 mm/page_io.c: use blk_io_schedule() for avoiding task hung in sync io
swap_readpage() does the sync io for one page, the io is not big,
normally, the io can be finished quickly, but it may take long time or
wait forever in case of io failure or discard.

This patch uses blk_io_schedule() instead of io_schedule() to avoid task
hung and crash (when set /proc/sys/kernel/hung_task_panic) when the above
exception occurs.

This is similar to the hung task avoidance in submit_bio_wait(),
blk_execute_rq() and __blkdev_direct_IO().

Signed-off-by: Xianting Tian <xianting_tian@126.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Hugh Dickins <hughd@google.com>
Link: http://lkml.kernel.org/r/1596461807-21087-1-git-send-email-xianting_tian@126.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07 11:33:24 -07:00
Christoph Hellwig a18b9b1590 block: move bio_associate_blkg_from_page to mm/page_io.c
bio_associate_blkg_from_page is a special purpose helper for swap bios
that doesn't need access to bio internals.  Move it to the swap code
instead of having it in bio.c.

Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-29 09:09:08 -06:00
Mike Rapoport e31cf2f4ca mm: don't include asm/pgtable.h if linux/mm.h is already included
Patch series "mm: consolidate definitions of page table accessors", v2.

The low level page table accessors (pXY_index(), pXY_offset()) are
duplicated across all architectures and sometimes more than once.  For
instance, we have 31 definition of pgd_offset() for 25 supported
architectures.

Most of these definitions are actually identical and typically it boils
down to, e.g.

static inline unsigned long pmd_index(unsigned long address)
{
        return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
}

static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
{
        return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address);
}

These definitions can be shared among 90% of the arches provided
XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined.

For architectures that really need a custom version there is always
possibility to override the generic version with the usual ifdefs magic.

These patches introduce include/linux/pgtable.h that replaces
include/asm-generic/pgtable.h and add the definitions of the page table
accessors to the new header.

This patch (of 12):

The linux/mm.h header includes <asm/pgtable.h> to allow inlining of the
functions involving page table manipulations, e.g.  pte_alloc() and
pmd_alloc().  So, there is no point to explicitly include <asm/pgtable.h>
in the files that include <linux/mm.h>.

The include statements in such cases are remove with a simple loop:

	for f in $(git grep -l "include <linux/mm.h>") ; do
		sed -i -e '/include <asm\/pgtable.h>/ d' $f
	done

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org
Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:13 -07:00
Carlos Maiolino 30460e1ea3 fs: Enable bmap() function to properly return errors
By now, bmap() will either return the physical block number related to
the requested file offset or 0 in case of error or the requested offset
maps into a hole.
This patch makes the needed changes to enable bmap() to proper return
errors, using the return value as an error return, and now, a pointer
must be passed to bmap() to be filled with the mapped physical block.

It will change the behavior of bmap() on return:

- negative value in case of error
- zero on success or map fell into a hole

In case of a hole, the *block will be zero too

Since this is a prep patch, by now, the only error return is -EINVAL if
->bmap doesn't exist.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-03 08:05:37 -05:00
Minchan Kim 937790699b mm/page_io.c: annotate refault stalls from swap_readpage
If a block device supports rw_page operation, it doesn't submit bios so
the annotation in submit_bio() for refault stall doesn't work.  It
happens with zram in android, especially swap read path which could
consume CPU cycle for decompress.  It is also a problem for zswap which
uses frontswap.

Annotate swap_readpage() to account the synchronous IO overhead to
prevent underreport memory pressure.

[akpm@linux-foundation.org: add comment, per Johannes]
Link: http://lkml.kernel.org/r/20191010152134.38545-1-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-01 12:59:11 -08:00
Vinayak Menon 5df373e956 mm/page_io.c: do not free shared swap slots
The following race is observed due to which a processes faulting on a
swap entry, finds the page neither in swapcache nor swap.  This causes
zram to give a zero filled page that gets mapped to the process,
resulting in a user space crash later.

Consider parent and child processes Pa and Pb sharing the same swap slot
with swap_count 2.  Swap is on zram with SWP_SYNCHRONOUS_IO set.
Virtual address 'VA' of Pa and Pb points to the shared swap entry.

Pa                                       Pb

fault on VA                              fault on VA
do_swap_page                             do_swap_page
lookup_swap_cache fails                  lookup_swap_cache fails
                                         Pb scheduled out
swapin_readahead (deletes zram entry)
swap_free (makes swap_count 1)
                                         Pb scheduled in
                                         swap_readpage (swap_count == 1)
                                         Takes SWP_SYNCHRONOUS_IO path
                                         zram enrty absent
                                         zram gives a zero filled page

Fix this by making sure that swap slot is freed only when swap count
drops down to one.

Link: http://lkml.kernel.org/r/1571743294-14285-1-git-send-email-vinmenon@codeaurora.org
Fixes: aa8d22a11d ("mm: swap: SWP_SYNCHRONOUS_IO: skip swapcache only if swapped page has no other reference")
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
Suggested-by: Minchan Kim <minchan@google.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-11-15 18:34:00 -08:00
Aaron Lu 4efaceb1c5 mm, swap: use rbtree for swap_extent
swap_extent is used to map swap page offset to backing device's block
offset.  For a continuous block range, one swap_extent is used and all
these swap_extents are managed in a linked list.

These swap_extents are used by map_swap_entry() during swap's read and
write path.  To find out the backing device's block offset for a page
offset, the swap_extent list will be traversed linearly, with
curr_swap_extent being used as a cache to speed up the search.

This works well as long as swap_extents are not huge or when the number
of processes that access swap device are few, but when the swap device
has many extents and there are a number of processes accessing the swap
device concurrently, it can be a problem.  On one of our servers, the
disk's remaining size is tight:

  $df -h
  Filesystem      Size  Used Avail Use% Mounted on
  ... ...
  /dev/nvme0n1p1  1.8T  1.3T  504G  72% /home/t4

When creating a 80G swapfile there, there are as many as 84656 swap
extents.  The end result is, kernel spends abou 30% time in
map_swap_entry() and swap throughput is only 70MB/s.

As a comparison, when I used smaller sized swapfile, like 4G whose
swap_extent dropped to 2000, swap throughput is back to 400-500MB/s and
map_swap_entry() is about 3%.

One downside of using rbtree for swap_extent is, 'struct rbtree' takes
24 bytes while 'struct list_head' takes 16 bytes, that's 8 bytes more
for each swap_extent.  For a swapfile that has 80k swap_extents, that
means 625KiB more memory consumed.

Test:

Since it's not possible to reboot that server, I can not test this patch
diretly there.  Instead, I tested it on another server with NVMe disk.

I created a 20G swapfile on an NVMe backed XFS fs.  By default, the
filesystem is quite clean and the created swapfile has only 2 extents.
Testing vanilla and this patch shows no obvious performance difference
when swapfile is not fragmented.

To see the patch's effects, I used some tweaks to manually fragment the
swapfile by breaking the extent at 1M boundary.  This made the swapfile
have 20K extents.

  nr_task=4
  kernel   swapout(KB/s) map_swap_entry(perf)  swapin(KB/s) map_swap_entry(perf)
  vanilla  165191           90.77%             171798          90.21%
  patched  858993 +420%      2.16%             715827 +317%     0.77%

  nr_task=8
  kernel   swapout(KB/s) map_swap_entry(perf)  swapin(KB/s) map_swap_entry(perf)
  vanilla  306783           92.19%             318145          87.76%
  patched  954437 +211%      2.35%            1073741 +237%     1.57%

swapout: the throughput of swap out, in KB/s, higher is better 1st
map_swap_entry: cpu cycles percent sampled by perf swapin: the
throughput of swap in, in KB/s, higher is better.  2nd map_swap_entry:
cpu cycles percent sampled by perf

nr_task=1 doesn't show any difference, this is due to the curr_swap_extent
can be effectively used to cache the correct swap extent for single task
workload.

[akpm@linux-foundation.org: s/BUG_ON(1)/BUG()/]
Link: http://lkml.kernel.org/r/20190523142404.GA181@aaronlu
Signed-off-by: Aaron Lu <ziqian.lzq@antfin.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-12 11:05:43 -07:00
Oleg Nesterov 8751853091 swap_readpage(): avoid blk_wake_io_task() if !synchronous
swap_readpage() sets waiter = bio->bi_private even if synchronous = F,
this means that the caller can get the spurious wakeup after return.

This can be fatal if blk_wake_io_task() does
set_current_state(TASK_RUNNING) after the caller does
set_special_state(), in the worst case the kernel can crash in
do_task_dead().

Link: http://lkml.kernel.org/r/20190704160301.GA5956@redhat.com
Fixes: 0619317ff8 ("block: add polled wakeup task helper")
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Qian Cai <cai@lca.pw>
Acked-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-05 11:12:07 +09:00
Huang Ying 1a5f439c7c mm, swap: fix THP swap out
0-Day test system reported some OOM regressions for several THP
(Transparent Huge Page) swap test cases.  These regressions are bisected
to 6861428921 ("block: always define BIO_MAX_PAGES as 256").  In the
commit, BIO_MAX_PAGES is set to 256 even when THP swap is enabled.  So the
bio_alloc(gfp_flags, 512) in get_swap_bio() may fail when swapping out
THP.  That causes the OOM.

As in the patch description of 6861428921 ("block: always define
BIO_MAX_PAGES as 256"), THP swap should use multi-page bvec to write THP
to swap space.  So the issue is fixed via doing that in get_swap_bio().

BTW: I remember I have checked the THP swap code when 6861428921
("block: always define BIO_MAX_PAGES as 256") was merged, and thought the
THP swap code needn't to be changed.  But apparently, I was wrong.  I
should have done this at that time.

Link: http://lkml.kernel.org/r/20190624075515.31040-1-ying.huang@intel.com
Fixes: 6861428921 ("block: always define BIO_MAX_PAGES as 256")
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-06-29 16:43:45 +08:00