linux.git/mm/page-writeback.c, branch v5.14

Merge tag 'for-5.14/block-2021-06-29' of git://git.kernel.dk/linux-block

2021-06-30T19:12:56+00:00

Pull core block updates from Jens Axboe:

 - disk events cleanup (Christoph)

 - gendisk and request queue allocation simplifications (Christoph)

 - bdev_disk_changed cleanups (Christoph)

 - IO priority improvements (Bart)

 - Chained bio completion trace fix (Edward)

 - blk-wbt fixes (Jan)

 - blk-wbt enable/disable fix (Zhang)

 - Scheduler dispatch improvements (Jan, Ming)

 - Shared tagset scheduler improvements (John)

 - BFQ updates (Paolo, Luca, Pietro)

 - BFQ lock inversion fix (Jan)

 - Documentation improvements (Kir)

 - CLONE_IO block cgroup fix (Tejun)

 - Remove of ancient and deprecated block dump feature (zhangyi)

 - Discard merge fix (Ming)

 - Misc fixes or followup fixes (Colin, Damien, Dan, Long, Max, Thomas,
   Yang)

* tag 'for-5.14/block-2021-06-29' of git://git.kernel.dk/linux-block: (129 commits)
  block: fix discard request merge
  block/mq-deadline: Remove a WARN_ON_ONCE() call
  blk-mq: update hctx->dispatch_busy in case of real scheduler
  blk: Fix lock inversion between ioc lock and bfqd lock
  bfq: Remove merged request already in bfq_requests_merged()
  block: pass a gendisk to bdev_disk_changed
  block: move bdev_disk_changed
  block: add the events* attributes to disk_attrs
  block: move the disk events code to a separate file
  block: fix trace completion for chained bio
  block/partitions/msdos: Fix typo inidicator -> indicator
  block, bfq: reset waker pointer with shared queues
  block, bfq: check waker only for queues with no in-flight I/O
  block, bfq: avoid delayed merge of async queues
  block, bfq: boost throughput by extending queue-merging times
  block, bfq: consider also creation time in delayed stable merge
  block, bfq: fix delayed stable merge check
  block, bfq: let also stably merged queues enjoy weight raising
  blk-wbt: make sure throttle is enabled properly
  blk-wbt: introduce a new disable state to prevent false positive by rwb_enabled()
  ...

fs: remove noop_set_page_dirty()

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

Use __set_page_dirty_no_writeback() instead.  This will set the dirty bit
on the page, which will be used to avoid calling set_page_dirty() in the
future.  It will have no effect on actually writing the page back, as the
pages are not on any LRU lists.

[akpm@linux-foundation.org: export __set_page_dirty_no_writeback() to modules]

Link: https://lkml.kernel.org/r/20210615162342.1669332-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) 
Cc: Al Viro 
Cc: Christoph Hellwig 
Cc: Dan Williams 
Cc: Greg Kroah-Hartman 
Cc: Jan Kara 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/writeback: use __set_page_dirty in __set_page_dirty_nobuffers

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

This is fundamentally the same code, so just call it instead of
duplicating it.

Link: https://lkml.kernel.org/r/20210615162342.1669332-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Greg Kroah-Hartman 
Cc: Al Viro 
Cc: Dan Williams 
Cc: Jan Kara 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

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

mm: require ->set_page_dirty to be explicitly wired up

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

Remove the CONFIG_BLOCK default to __set_page_dirty_buffers and just wire
that method up for the missing instances.

[hch@lst.de: ecryptfs: add a ->set_page_dirty cludge]
  Link: https://lkml.kernel.org/r/20210624125250.536369-1-hch@lst.de

Link: https://lkml.kernel.org/r/20210614061512.3966143-4-hch@lst.de
Signed-off-by: Christoph Hellwig 
Reviewed-by: Greg Kroah-Hartman 
Reviewed-by: Jan Kara 
Cc: Al Viro 
Cc: Matthew Wilcox (Oracle) 
Cc: Tyler Hicks 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/page-writeback: use __this_cpu_inc() in account_page_dirtied()

2021-06-29T17:53:47+00:00

As account_page_dirtied() was always protected by xa_lock_irqsave(), so
using __this_cpu_inc() is better.

Link: https://lkml.kernel.org/r/20210512144742.4764-1-wuchi.zero@gmail.com
Signed-off-by: Chi Wu 
Reviewed-by: Jan Kara 
Cc: Howard Cochran 
Cc: Miklos Szeredi 
Cc: Sedat Dilek 
Cc: Tejun Heo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/page-writeback: update the comment of Dirty position control

2021-06-29T17:53:47+00:00

As the value of pos_ratio_polynom() clamp between 0 and 2LL <<
RATELIMIT_CALC_SHIFT, the global control line should be consistent with
it.

Link: https://lkml.kernel.org/r/20210511103606.3732-1-wuchi.zero@gmail.com
Signed-off-by: Chi Wu 
Reviewed-by: Jan Kara 
Cc: Jens Axboe 
Cc: Howard Cochran 
Cc: Miklos Szeredi 
Cc: Sedat Dilek 
Cc: Tejun Heo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/page-writeback: Fix performance when BDI's share of ratio is 0.

2021-06-29T17:53:47+00:00

Fix performance when BDI's share of ratio is 0.

The issue is similar to commit 74d369443325 ("writeback: Fix
performance regression in wb_over_bg_thresh()").

Balance_dirty_pages and the writeback worker will also disagree on
whether writeback when a BDI uses BDI_CAP_STRICTLIMIT and BDI's share
of the thresh ratio is zero.

For example, A thread on cpu0 writes 32 pages and then
balance_dirty_pages, it will wake up background writeback and pauses
because wb_dirty > wb->wb_thresh = 0 (share of thresh ratio is zero).
A thread may runs on cpu0 again because scheduler prefers pre_cpu.
Then writeback worker may runs on other cpus(1,2..) which causes the
value of wb_stat(wb, WB_RECLAIMABLE) in wb_over_bg_thresh is 0 and does
not writeback and returns.

Thus, balance_dirty_pages keeps looping, sleeping and then waking up the
worker who will do nothing. It remains stuck in this state until the
writeback worker hit the right dirty cpu or the dirty pages expire.

The fix that we should get the wb_stat_sum radically when thresh is low.

Link: https://lkml.kernel.org/r/20210428225046.16301-1-wuchi.zero@gmail.com
Signed-off-by: Chi Wu 
Reviewed-by: Jan Kara 
Cc: Tejun Heo 
Cc: Miklos Szeredi 
Cc: Sedat Dilek 
Cc: Jens Axboe 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: page-writeback: kill get_writeback_state() comments

2021-06-29T17:53:47+00:00

The get_writeback_state() has gone since 2006, kill related comments.

Link: https://lkml.kernel.org/r/20210508125026.56600-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

block_dump: remove block_dump feature

2021-05-24T12:47:21+00:00

We have already delete block_dump feature in mark_inode_dirty() because
it can be replaced by tracepoints, now we also remove the part in
submit_bio() for the same reason. The part of block dump feature in
submit_bio() dump the write process, write region and sectors on the
target disk into kernel message. it can be replaced by
block_bio_queue tracepoint in submit_bio_checks(), so we do not need
block_dump anymore, remove the whole block_dump feature.

Signed-off-by: zhangyi (F) 
Reviewed-by: Jan Kara 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20210313030146.2882027-3-yi.zhang@huawei.com
Signed-off-by: Jens Axboe