mm/writeback: Add __folio_end_writeback()

test_clear_page_writeback() is actually an mm-internal function, although
it's named as if it's a pagecache function. Move it to mm/internal.h,
rename it t

mm/writeback: Add __folio_end_writeback()

test_clear_page_writeback() is actually an mm-internal function, although
it's named as if it's a pagecache function. Move it to mm/internal.h,
rename it to __folio_end_writeback() and change the return type to bool.

The conversion from page to folio is mostly about accounting the number
of pages being written back, although it does eliminate a couple of
calls to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Howells <dhowells@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>

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mm/writeback: Change __wb_writeout_inc() to __wb_writeout_add()

Allow for accounting N pages at once instead of one page at a time.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Revi

mm/writeback: Change __wb_writeout_inc() to __wb_writeout_add()

Allow for accounting N pages at once instead of one page at a time.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: David Howells <dhowells@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>

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flex_proportions: Allow N events instead of 1

When batching events (such as writing back N pages in a single I/O), it
is better to do one flex_proportion operation instead of N. There is
only one c

flex_proportions: Allow N events instead of 1

When batching events (such as writing back N pages in a single I/O), it
is better to do one flex_proportion operation instead of N. There is
only one caller of __fprop_inc_percpu_max(), and it's the one we're
going to change in the next patch, so rename it instead of adding a
compatibility wrapper.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>

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Merge branch 'pruss-fix' into fixes

Merge in a fix for pruss reset issue caused by enabling pruss for am335x.

mm/filemap: Add folio_wait_bit()

Rename wait_on_page_bit() to folio_wait_bit(). We must always wait on
the folio, otherwise we won't be woken up due to the tail page hashing
to a different bucket f

mm/filemap: Add folio_wait_bit()

Rename wait_on_page_bit() to folio_wait_bit(). We must always wait on
the folio, otherwise we won't be woken up due to the tail page hashing
to a different bucket from the head page.

This commit shrinks the kernel by 770 bytes, mostly due to moving
the page waitqueue lookup into folio_wait_bit_common().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>

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mm/writeback: Add folio_wait_stable()

Move wait_for_stable_page() into the folio compatibility file.
folio_wait_stable() avoids a call to compound_head() and is 14 bytes
smaller than wait_for_stable

mm/writeback: Add folio_wait_stable()

Move wait_for_stable_page() into the folio compatibility file.
folio_wait_stable() avoids a call to compound_head() and is 14 bytes
smaller than wait_for_stable_page() was. The net text size grows by 16
bytes as a result of this patch. We can also remove thp_head() as this
was the last user.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: David Howells <dhowells@redhat.com>

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mm/writeback: Add folio_wait_writeback()

wait_on_page_writeback_killable() only has one caller, so convert it to
call folio_wait_writeback_killable(). For the wait_on_page_writeback()
callers, add

mm/writeback: Add folio_wait_writeback()

wait_on_page_writeback_killable() only has one caller, so convert it to
call folio_wait_writeback_killable(). For the wait_on_page_writeback()
callers, add a compatibility wrapper around folio_wait_writeback().

Turning PageWriteback() into folio_test_writeback() eliminates a call
to compound_head() which saves 8 bytes and 15 bytes in the two
functions. Unfortunately, that is more than offset by adding the
wait_on_page_writeback compatibility wrapper for a net increase in text
of 7 bytes.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: David Howells <dhowells@redhat.com>

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Merge tag 'v5.15-rc2' into spi-5.15

Linux 5.15-rc2

Merge drm/drm-next into drm-intel-next

Catch-up on 5.15-rc1 and sync with drm-intel-gt-next
to prepare the PXP topic branch.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

Merge drm/drm-next into drm-intel-gt-next

Close the divergence which has caused patches not to apply and
have a solid baseline for the PXP patches that Rodrigo will send
a topic branch PR for.

Sign

Merge drm/drm-next into drm-intel-gt-next

Close the divergence which has caused patches not to apply and
have a solid baseline for the PXP patches that Rodrigo will send
a topic branch PR for.

Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

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Merge drm/drm-next into drm-misc-next

Kickstart new drm-misc-next cycle.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>

Merge branch 'linus' into smp/urgent

Ensure that all usage sites of get/put_online_cpus() except for the
struggler in drivers/thermal are gone. So the last user and the deprecated
inlines can be rem

Merge branch 'linus' into smp/urgent

Ensure that all usage sites of get/put_online_cpus() except for the
struggler in drivers/thermal are gone. So the last user and the deprecated
inlines can be removed.

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Merge branch 'next' into for-linus

Prepare input updates for 5.15 merge window.

Merge branch 'akpm' (patches from Andrew)

Merge misc updates from Andrew Morton:
"173 patches.

Subsystems affected by this series: ia64, ocfs2, block, and mm (debug,
pagecache, gup, swap, shme

Merge branch 'akpm' (patches from Andrew)

Merge misc updates from Andrew Morton:
"173 patches.

Subsystems affected by this series: ia64, ocfs2, block, and mm (debug,
pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap,
bootmem, sparsemem, vmalloc, kasan, pagealloc, memory-failure,
hugetlb, userfaultfd, vmscan, compaction, mempolicy, memblock,
oom-kill, migration, ksm, percpu, vmstat, and madvise)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (173 commits)
mm/madvise: add MADV_WILLNEED to process_madvise()
mm/vmstat: remove unneeded return value
mm/vmstat: simplify the array size calculation
mm/vmstat: correct some wrong comments
mm/percpu,c: remove obsolete comments of pcpu_chunk_populated()
selftests: vm: add COW time test for KSM pages
selftests: vm: add KSM merging time test
mm: KSM: fix data type
selftests: vm: add KSM merging across nodes test
selftests: vm: add KSM zero page merging test
selftests: vm: add KSM unmerge test
selftests: vm: add KSM merge test
mm/migrate: correct kernel-doc notation
mm: wire up syscall process_mrelease
mm: introduce process_mrelease system call
memblock: make memblock_find_in_range method private
mm/mempolicy.c: use in_task() in mempolicy_slab_node()
mm/mempolicy: unify the create() func for bind/interleave/prefer-many policies
mm/mempolicy: advertise new MPOL_PREFERRED_MANY
mm/hugetlb: add support for mempolicy MPOL_PREFERRED_MANY
...

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writeback: use READ_ONCE for unlocked reads of writeback stats

We do some unlocked reads of writeback statistics like
avg_write_bandwidth, dirty_ratelimit, or bw_time_stamp. Generally we are
fine w

writeback: use READ_ONCE for unlocked reads of writeback stats

We do some unlocked reads of writeback statistics like
avg_write_bandwidth, dirty_ratelimit, or bw_time_stamp. Generally we are
fine with getting somewhat out-of-date values but actually getting
different values in various parts of the functions because the compiler
decided to reload value from original memory location could confuse
calculations. Use READ_ONCE for these unlocked accesses and WRITE_ONCE
for the updates to be on the safe side.

Link: https://lkml.kernel.org/r/20210713104716.22868-5-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Michael Stapelberg <stapelberg+linux@google.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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writeback: rename domain_update_bandwidth()

Rename domain_update_bandwidth() to domain_update_dirty_limit(). The
original name is a misnomer. The function has nothing to do with a
bandwidth, it up

writeback: rename domain_update_bandwidth()

Rename domain_update_bandwidth() to domain_update_dirty_limit(). The
original name is a misnomer. The function has nothing to do with a
bandwidth, it updates dirty limits.

Link: https://lkml.kernel.org/r/20210713104716.22868-4-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Michael Stapelberg <stapelberg+linux@google.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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writeback: fix bandwidth estimate for spiky workload

Michael Stapelberg has reported that for workload with short big spikes of
writes (GCC linker seem to trigger this frequently) the write throughp

writeback: fix bandwidth estimate for spiky workload

Michael Stapelberg has reported that for workload with short big spikes of
writes (GCC linker seem to trigger this frequently) the write throughput
is heavily underestimated and tends to steadily sink until it reaches
zero. This has rather bad impact on writeback throttling (causing
stalls). The problem is that writeback throughput estimate gets updated
at most once per 200 ms. One update happens early after we submit pages
for writeback (at that point writeout of only small fraction of pages is
completed and thus observed throughput is tiny). Next update happens only
during the next write spike (updates happen only from inode writeback and
dirty throttling code) and if that is more than 1s after previous spike,
we decide system was idle and just ignore whatever was written until this
moment.

Fix the problem by making sure writeback throughput estimate is also
updated shortly after writeback completes to get reasonable estimate of
throughput for spiky workloads.

[jack@suse.cz: avoid division by 0 in wb_update_dirty_ratelimit()]

Link: https://lore.kernel.org/lkml/20210617095309.3542373-1-stapelberg+linux@google.com
Link: https://lkml.kernel.org/r/20210713104716.22868-3-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reported-by: Michael Stapelberg <stapelberg+linux@google.com>
Tested-by: Michael Stapelberg <stapelberg+linux@google.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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writeback: reliably update bandwidth estimation

Currently we trigger writeback bandwidth estimation from
balance_dirty_pages() and from wb_writeback(). However neither of these
need to trigger when

writeback: reliably update bandwidth estimation

Currently we trigger writeback bandwidth estimation from
balance_dirty_pages() and from wb_writeback(). However neither of these
need to trigger when the system is relatively idle and writeback is
triggered e.g. from fsync(2). Make sure writeback estimates happen
reliably by triggering them from do_writepages().

Link: https://lkml.kernel.org/r/20210713104716.22868-2-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Michael Stapelberg <stapelberg+linux@google.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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writeback: track number of inodes under writeback

Patch series "writeback: Fix bandwidth estimates", v4.

Fix estimate of writeback throughput when device is not fully busy doing
writeback. Michael

writeback: track number of inodes under writeback

Patch series "writeback: Fix bandwidth estimates", v4.

Fix estimate of writeback throughput when device is not fully busy doing
writeback. Michael Stapelberg has reported that such workload (e.g.
generated by linking) tends to push estimated throughput down to 0 and as
a result writeback on the device is practically stalled.

The first three patches fix the reported issue, the remaining two patches
are unrelated cleanups of problems I've noticed when reading the code.

This patch (of 4):

Track number of inodes under writeback for each bdi_writeback structure.
We will use this to decide whether wb does any IO and so we can estimate
its writeback throughput. In principle we could use number of pages under
writeback (WB_WRITEBACK counter) for this however normal percpu counter
reads are too inaccurate for our purposes and summing the counter is too
expensive.

Link: https://lkml.kernel.org/r/20210713104519.16394-1-jack@suse.cz
Link: https://lkml.kernel.org/r/20210713104716.22868-1-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Michael Stapelberg <stapelberg+linux@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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Merge tag 'for-5.15/block-2021-08-30' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:
"Nothing major in here - lots of good cleanups and tech debt handling,
which is also e

Merge tag 'for-5.15/block-2021-08-30' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:
"Nothing major in here - lots of good cleanups and tech debt handling,
which is also evident in the diffstats. In particular:

- Add disk sequence numbers (Matteo)

- Discard merge fix (Ming)

- Relax disk zoned reporting restrictions (Niklas)

- Bio error handling zoned leak fix (Pavel)

- Start of proper add_disk() error handling (Luis, Christoph)

- blk crypto fix (Eric)

- Non-standard GPT location support (Dmitry)

- IO priority improvements and cleanups (Damien)o

- blk-throtl improvements (Chunguang)

- diskstats_show() stack reduction (Abd-Alrhman)

- Loop scheduler selection (Bart)

- Switch block layer to use kmap_local_page() (Christoph)

- Remove obsolete disk_name helper (Christoph)

- block_device refcounting improvements (Christoph)

- Ensure gendisk always has a request queue reference (Christoph)

- Misc fixes/cleanups (Shaokun, Oliver, Guoqing)"

* tag 'for-5.15/block-2021-08-30' of git://git.kernel.dk/linux-block: (129 commits)
sg: pass the device name to blk_trace_setup
block, bfq: cleanup the repeated declaration
blk-crypto: fix check for too-large dun_bytes
blk-zoned: allow BLKREPORTZONE without CAP_SYS_ADMIN
blk-zoned: allow zone management send operations without CAP_SYS_ADMIN
block: mark blkdev_fsync static
block: refine the disk_live check in del_gendisk
mmc: sdhci-tegra: Enable MMC_CAP2_ALT_GPT_TEGRA
mmc: block: Support alternative_gpt_sector() operation
partitions/efi: Support non-standard GPT location
block: Add alternative_gpt_sector() operation
bio: fix page leak bio_add_hw_page failure
block: remove CONFIG_DEBUG_BLOCK_EXT_DEVT
block: remove a pointless call to MINOR() in device_add_disk
null_blk: add error handling support for add_disk()
virtio_blk: add error handling support for add_disk()
block: add error handling for device_add_disk / add_disk
block: return errors from disk_alloc_events
block: return errors from blk_integrity_add
block: call blk_register_queue earlier in device_add_disk
...

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Merge branch 'for-5.15-printk-index' into for-linus

Merge branch 'perf/urgent' into perf/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'v5.14-rc6' into locking/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

mm: hide laptop_mode_wb_timer entirely behind the BDI API

Don't leak the detaіls of the timer into the block layer, instead
initialize the timer in bdi_alloc and delete it in bdi_unregister.
Note th

mm: hide laptop_mode_wb_timer entirely behind the BDI API

Don't leak the detaіls of the timer into the block layer, instead
initialize the timer in bdi_alloc and delete it in bdi_unregister.
Note that this means the timer is initialized (but not armed) for
non-block queues as well now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210809141744.1203023-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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Backmerge remote-tracking branch 'drm/drm-next' into drm-misc-next

Required bump from v5.13-rc3 to v5.14-rc3, and to pick up sysfb compilation fixes.

Signed-off-by: Maarten Lankhorst <maarten.lankh

Backmerge remote-tracking branch 'drm/drm-next' into drm-misc-next

Required bump from v5.13-rc3 to v5.14-rc3, and to pick up sysfb compilation fixes.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

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