linux-toradex.git/fs/buffer.c, branch v5.15-rc5

mm: fs: invalidate bh_lrus for only cold path

2021-09-24T23:13:35+00:00

The kernel test robot reported the regression of fio.write_iops[1] with
commit 8cc621d2f45d ("mm: fs: invalidate BH LRU during page migration").

Since lru_add_drain is called frequently, invalidate bh_lrus there could
increase bh_lrus cache miss ratio, which needs more IO in the end.

This patch moves the bh_lrus invalidation from the hot path( e.g.,
zap_page_range, pagevec_release) to cold path(i.e., lru_add_drain_all,
lru_cache_disable).

Zhengjun Xing confirmed
 "I test the patch, the regression reduced to -2.9%"

[1] https://lore.kernel.org/lkml/20210520083144.GD14190@xsang-OptiPlex-9020/
[2] 8cc621d2f45d, mm: fs: invalidate BH LRU during page migration

Link: https://lkml.kernel.org/r/20210907212347.1977686-1-minchan@kernel.org
Signed-off-by: Minchan Kim 
Reported-by: kernel test robot 
Reviewed-by: Chris Goldsworthy 
Tested-by: "Xing, Zhengjun" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'exit-cleanups-for-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

2021-09-01T21:52:05+00:00

Pull exit cleanups from Eric Biederman:
 "In preparation of doing something about PTRACE_EVENT_EXIT I have
  started cleaning up various pieces of code related to do_exit. Most of
  that code I did not manage to get tested and reviewed before the merge
  window opened but a handful of very useful cleanups are ready to be
  merged.

  The first change is simply the removal of the bdflush system call. The
  code has now been disabled long enough that even the oldest userspace
  working userspace setups anyone can find to test are fine with the
  bdflush system call being removed.

  Changing m68k fsp040_die to use force_sigsegv(SIGSEGV) instead of
  calling do_exit directly is interesting only in that it is nearly the
  most difficult of the incorrect uses of do_exit to remove.

  The change to the seccomp code to simply send a signal instead of
  calling do_coredump directly is a very nice little cleanup made
  possible by realizing the existing signal sending helpers were missing
  a little bit of functionality that is easy to provide"

* 'exit-cleanups-for-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  signal/seccomp: Dump core when there is only one live thread
  signal/seccomp: Refactor seccomp signal and coredump generation
  signal/m68k: Use force_sigsegv(SIGSEGV) in fpsp040_die
  exit/bdflush: Remove the deprecated bdflush system call

fs: mark the iomap argument to __block_write_begin_int const

2021-08-17T04:26:33+00:00

__block_write_begin_int never modifies the passed in iomap, so mark it
const.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Darrick J. Wong 
Signed-off-by: Darrick J. Wong

exit/bdflush: Remove the deprecated bdflush system call

2021-07-12T20:17:47+00:00

The bdflush system call has been deprecated for a very long time.
Recently Michael Schmitz tested[1] and found that the last known
caller of of the bdflush system call is unaffected by it's removal.

Since the code is not needed delete it.

[1] https://lkml.kernel.org/r/36123b5d-daa0-6c2b-f2d4-a942f069fd54@gmail.com
Link: https://lkml.kernel.org/r/87sg10quue.fsf_-_@disp2133
Tested-by: Michael Schmitz 
Acked-by: Geert Uytterhoeven 
Reviewed-by: Arnd Bergmann 
Acked-by: Cyril Hrubis 
Signed-off-by: "Eric W. Biederman"

mm/writeback: move __set_page_dirty() to core mm

2021-06-29T17:53:48+00:00

Patch series "Further set_page_dirty cleanups".

Prompted by Christoph's recent patches, here are some more patches to
improve the state of set_page_dirty().  They're all from the folio tree,
so they've been tested to a certain extent.

This patch (of 6):

Nothing in __set_page_dirty() is specific to buffer_head, so move it to
mm/page-writeback.c.  That removes the only caller of
account_page_dirtied() outside of page-writeback.c, so make it static.

Link: https://lkml.kernel.org/r/20210615162342.1669332-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20210615162342.1669332-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Greg Kroah-Hartman 
Cc: Jan Kara 
Cc: Al Viro 
Cc: Dan Williams 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fs: unexport __set_page_dirty

2021-06-29T17:53:48+00:00

Patch series "remove the implicit .set_page_dirty default".

This series cleans up a few lose ends around ->set_page_dirty, most
importantly removes the default to the buffer head based on if no method
is wired up.

This patch (of 3):

__set_page_dirty is only used by built-in code.

Link: https://lkml.kernel.org/r/20210614061512.3966143-1-hch@lst.de
Link: https://lkml.kernel.org/r/20210614061512.3966143-2-hch@lst.de
Signed-off-by: Christoph Hellwig 
Reviewed-by: Greg Kroah-Hartman 
Reviewed-by: Jan Kara 
Reviewed-by: Matthew Wilcox (Oracle) 
Cc: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'akpm' (patches from Andrew)

2021-05-05T20:50:15+00:00

Merge more updates from Andrew Morton:
 "The remainder of the main mm/ queue.

  143 patches.

  Subsystems affected by this patch series (all mm): pagecache, hugetlb,
  userfaultfd, vmscan, compaction, migration, cma, ksm, vmstat, mmap,
  kconfig, util, memory-hotplug, zswap, zsmalloc, highmem, cleanups, and
  kfence"

* emailed patches from Andrew Morton : (143 commits)
  kfence: use power-efficient work queue to run delayed work
  kfence: maximize allocation wait timeout duration
  kfence: await for allocation using wait_event
  kfence: zero guard page after out-of-bounds access
  mm/process_vm_access.c: remove duplicate include
  mm/mempool: minor coding style tweaks
  mm/highmem.c: fix coding style issue
  btrfs: use memzero_page() instead of open coded kmap pattern
  iov_iter: lift memzero_page() to highmem.h
  mm/zsmalloc: use BUG_ON instead of if condition followed by BUG.
  mm/zswap.c: switch from strlcpy to strscpy
  arm64/Kconfig: introduce ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
  x86/Kconfig: introduce ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
  mm,memory_hotplug: add kernel boot option to enable memmap_on_memory
  acpi,memhotplug: enable MHP_MEMMAP_ON_MEMORY when supported
  mm,memory_hotplug: allocate memmap from the added memory range
  mm,memory_hotplug: factor out adjusting present pages into adjust_present_page_count()
  mm,memory_hotplug: relax fully spanned sections check
  drivers/base/memory: introduce memory_block_{online,offline}
  mm/memory_hotplug: remove broken locking of zone PCP structures during hot remove
  ...

mm: fs: invalidate BH LRU during page migration

2021-05-05T18:27:24+00:00

Pages containing buffer_heads that are in one of the per-CPU buffer_head
LRU caches will be pinned and thus cannot be migrated.  This can prevent
CMA allocations from succeeding, which are often used on platforms with
co-processors (such as a DSP) that can only use physically contiguous
memory.  It can also prevent memory hot-unplugging from succeeding,
which involves migrating at least MIN_MEMORY_BLOCK_SIZE bytes of memory,
which ranges from 8 MiB to 1 GiB based on the architecture in use.

Correspondingly, invalidate the BH LRU caches before a migration starts
and stop any buffer_head from being cached in the LRU caches, until
migration has finished.

Link: https://lkml.kernel.org/r/20210319175127.886124-3-minchan@kernel.org
Signed-off-by: Minchan Kim 
Reported-by: Chris Goldsworthy 
Reported-by: Laura Abbott 
Tested-by: Oliver Sang 
Cc: David Hildenbrand 
Cc: John Dias 
Cc: Matthew Wilcox 
Cc: Michal Hocko 
Cc: Suren Baghdasaryan 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

buffer: a small optimization in grow_buffers

2021-03-22T15:30:03+00:00

This patch replaces a loop with a "tzcnt" instruction.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Al Viro

fs: buffer: use raw page_memcg() on locked page

2021-02-24T21:38:30+00:00

alloc_page_buffers() currently uses get_mem_cgroup_from_page() for
charging the buffers to the page owner, which does an rcu-protected
page->memcg lookup and acquires a reference.  But buffer allocation has
the page lock held throughout, which pins the page to the memcg and
thereby the memcg - neither rcu nor holding an extra reference during the
allocation are necessary.  Use a raw page_memcg() instead.

This was the last user of get_mem_cgroup_from_page(), delete it.

Link: https://lkml.kernel.org/r/20210209190126.97842-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner 
Reported-by: Muchun Song 
Reviewed-by: Shakeel Butt 
Acked-by: Roman Gushchin 
Acked-by: Michal Hocko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds