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<title>user/sven/linux.git/include/linux/buffer_head.h, branch v5.15.44</title>
<subtitle>Linux Kernel
</subtitle>
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<updated>2021-09-24T23:13:35Z</updated>
<entry>
<title>mm: fs: invalidate bh_lrus for only cold path</title>
<updated>2021-09-24T23:13:35Z</updated>
<author>
<name>Minchan Kim</name>
<email>minchan@kernel.org</email>
</author>
<published>2021-09-24T22:43:47Z</published>
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<id>urn:sha1:243418e3925d5b5b0657ae54c322d43035e97eed</id>
<content type='text'>
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 &lt;minchan@kernel.org&gt;
Reported-by: kernel test robot &lt;oliver.sang@intel.com&gt;
Reviewed-by: Chris Goldsworthy &lt;cgoldswo@codeaurora.org&gt;
Tested-by: "Xing, Zhengjun" &lt;zhengjun.xing@intel.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>include/linux/buffer_head.h: fix boolreturn.cocci warnings</title>
<updated>2021-09-03T16:58:10Z</updated>
<author>
<name>Jing Yangyang</name>
<email>jing.yangyang@zte.com.cn</email>
</author>
<published>2021-09-02T21:53:30Z</published>
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<id>urn:sha1:6de522d1667f628376517e4b177af10c739d745b</id>
<content type='text'>
./include/linux/buffer_head.h:412:64-65:WARNING:return of 0/1 in
function 'has_bh_in_lru' with return type bool

Return statements in functions returning bool should use true/false
instead of 1/0.

Generated by: scripts/coccinelle/misc/boolreturn.cocci

Link: https://lkml.kernel.org/r/20210824055828.58783-1-deng.changcheng@zte.com.cn
Signed-off-by: Jing Yangyang &lt;jing.yangyang@zte.com.cn&gt;
Reported-by: Zeal Robot &lt;zealci@zte.com.cn&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>mm: fs: invalidate BH LRU during page migration</title>
<updated>2021-05-05T18:27:24Z</updated>
<author>
<name>Minchan Kim</name>
<email>minchan@kernel.org</email>
</author>
<published>2021-05-05T01:37:00Z</published>
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<id>urn:sha1:8cc621d2f45ddd3dc664024a647ee7adf48d79a5</id>
<content type='text'>
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 &lt;minchan@kernel.org&gt;
Reported-by: Chris Goldsworthy &lt;cgoldswo@codeaurora.org&gt;
Reported-by: Laura Abbott &lt;labbott@kernel.org&gt;
Tested-by: Oliver Sang &lt;oliver.sang@intel.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: John Dias &lt;joaodias@google.com&gt;
Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>fs: move the buffer_heads_over_limit stub to buffer_head.h</title>
<updated>2020-06-24T15:16:02Z</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2020-06-20T07:16:42Z</published>
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<id>urn:sha1:d2de7ea48d83195ef1310555f1fdd9e8e1bab0d3</id>
<content type='text'>
Move the !CONFIG_BLOCK stub to the same place as the non-stub
declaration.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
</entry>
<entry>
<title>buffer_head.h: remove attach_page_buffers</title>
<updated>2020-06-02T17:59:08Z</updated>
<author>
<name>Guoqing Jiang</name>
<email>guoqing.jiang@cloud.ionos.com</email>
</author>
<published>2020-06-02T04:48:03Z</published>
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<id>urn:sha1:7b59435a2afed12dc9b2ec1b930efa2e94f1c397</id>
<content type='text'>
All the callers have replaced attach_page_buffers with the new function
attach_page_private, so remove it.

Signed-off-by: Guoqing Jiang &lt;guoqing.jiang@cloud.ionos.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Reviewed-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Cc: Roman Gushchin &lt;guro@fb.com&gt;
Cc: Andreas Dilger &lt;adilger@dilger.ca&gt;
Link: http://lkml.kernel.org/r/20200517214718.468-10-guoqing.jiang@cloud.ionos.com
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>ext4: use non-movable memory for superblock readahead</title>
<updated>2020-04-16T03:58:48Z</updated>
<author>
<name>Roman Gushchin</name>
<email>guro@fb.com</email>
</author>
<published>2020-02-29T00:14:11Z</published>
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<id>urn:sha1:d87f639258a6a5980183f11876c884931ad93da2</id>
<content type='text'>
Since commit a8ac900b8163 ("ext4: use non-movable memory for the
superblock") buffers for ext4 superblock were allocated using
the sb_bread_unmovable() helper which allocated buffer heads
out of non-movable memory blocks. It was necessarily to not block
page migrations and do not cause cma allocation failures.

However commit 85c8f176a611 ("ext4: preload block group descriptors")
broke this by introducing pre-reading of the ext4 superblock.
The problem is that __breadahead() is using __getblk() underneath,
which allocates buffer heads out of movable memory.

It resulted in page migration failures I've seen on a machine
with an ext4 partition and a preallocated cma area.

Fix this by introducing sb_breadahead_unmovable() and
__breadahead_gfp() helpers which use non-movable memory for buffer
head allocations and use them for the ext4 superblock readahead.

Reviewed-by: Andreas Dilger &lt;adilger@dilger.ca&gt;
Fixes: 85c8f176a611 ("ext4: preload block group descriptors")
Signed-off-by: Roman Gushchin &lt;guro@fb.com&gt;
Link: https://lore.kernel.org/r/20200229001411.128010-1-guro@fb.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</content>
</entry>
<entry>
<title>fs/buffer: Make BH_Uptodate_Lock bit_spin_lock a regular spinlock_t</title>
<updated>2020-03-28T12:21:08Z</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2019-11-18T13:28:24Z</published>
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<id>urn:sha1:f1e67e355c2aafeddf1eac31335709236996d2fe</id>
<content type='text'>
Bit spinlocks are problematic if PREEMPT_RT is enabled, because they
disable preemption, which is undesired for latency reasons and breaks when
regular spinlocks are taken within the bit_spinlock locked region because
regular spinlocks are converted to 'sleeping spinlocks' on RT.

PREEMPT_RT replaced the bit spinlocks with regular spinlocks to avoid this
problem. The replacement was done conditionaly at compile time, but
Christoph requested to do an unconditional conversion.

Jan suggested to move the spinlock into a existing padding hole which
avoids a size increase of struct buffer_head on production kernels.

As a benefit the lock gains lockdep coverage.

[ bigeasy: Remove the wrapper and use always spinlock_t and move it into
           the padding hole ]

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Cc: Christoph Hellwig &lt;hch@infradead.org&gt;
Link: https://lkml.kernel.org/r/20191118132824.rclhrbujqh4b4g4d@linutronix.de
</content>
</entry>
<entry>
<title>ext4: convert fault handler to use vm_fault_t type</title>
<updated>2018-10-03T02:20:50Z</updated>
<author>
<name>Souptick Joarder</name>
<email>jrdr.linux@gmail.com</email>
</author>
<published>2018-10-03T02:20:50Z</published>
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<id>urn:sha1:401b25aa1a75e7fe4e3202a6336604269697d705</id>
<content type='text'>
Return type of ext4_page_mkwrite and ext4_filemap_fault are
changed to use vm_fault_t type.

With this patch all the callers of block_page_mkwrite_return()
are changed to handle vm_fault_t. So converting the return type
of block_page_mkwrite_return() to vm_fault_t.

Signed-off-by: Souptick Joarder &lt;jrdr.linux@gmail.com&gt;
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Reviewed-by: Matthew Wilcox &lt;willy@infradead.org&gt;
</content>
</entry>
<entry>
<title>fs: move page_cache_seek_hole_data to iomap.c</title>
<updated>2018-06-02T01:37:33Z</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2018-06-01T16:04:40Z</published>
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<id>urn:sha1:8a78cb1f1b98e5ea970674e0f049832d19e76ace</id>
<content type='text'>
This function is only used by the iomap code, depends on being called
from it, and will soon stop poking into buffer head internals.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Andreas Gruenbacher &lt;agruenba@redhat.com&gt;
Reviewed-by: Dave Chinner &lt;dchinner@redhat.com&gt;
Reviewed-by: Darrick J. Wong &lt;darrick.wong@oracle.com&gt;
Signed-off-by: Darrick J. Wong &lt;darrick.wong@oracle.com&gt;
</content>
</entry>
<entry>
<title>Merge tag 'for-linus-20180204' of git://git.kernel.dk/linux-block</title>
<updated>2018-02-04T19:16:35Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-02-04T19:16:35Z</published>
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<id>urn:sha1:64b28683deba132f301d1cecfc25c32e295f53a1</id>
<content type='text'>
Pull more block updates from Jens Axboe:
 "Most of this is fixes and not new code/features:

   - skd fix from Arnd, fixing a build error dependent on sla allocator
     type.

   - blk-mq scheduler discard merging fixes, one from me and one from
     Keith. This fixes a segment miscalculation for blk-mq-sched, where
     we mistakenly think two segments are physically contigious even
     though the request isn't carrying real data. Also fixes a bio-to-rq
     merge case.

   - Don't re-set a bit on the buffer_head flags, if it's already set.
     This can cause scalability concerns on bigger machines and
     workloads. From Kemi Wang.

   - Add BLK_STS_DEV_RESOURCE return value to blk-mq, allowing us to
     distuingish between a local (device related) resource starvation
     and a global one. The latter might happen without IO being in
     flight, so it has to be handled a bit differently. From Ming"

* tag 'for-linus-20180204' of git://git.kernel.dk/linux-block:
  block: skd: fix incorrect linux/slab_def.h inclusion
  buffer: Avoid setting buffer bits that are already set
  blk-mq-sched: Enable merging discard bio into request
  blk-mq: fix discard merge with scheduler attached
  blk-mq: introduce BLK_STS_DEV_RESOURCE
</content>
</entry>
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