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* [PATCH 0/4 v3] ext4: Speedup orphan file handling
@ 2021-06-16 10:56 Jan Kara
  2021-06-16 10:56 ` [PATCH 1/4] ext4: Support for checksumming from journal triggers Jan Kara
                   ` (3 more replies)
  0 siblings, 4 replies; 16+ messages in thread
From: Jan Kara @ 2021-06-16 10:56 UTC (permalink / raw)
  To: Ted Tso; +Cc: linux-ext4, Jan Kara

  Hello,

After six years, prompted by recent 0-day reports of performance issues with
orphan list handling [1], I'm sending a third revision of my series to speed up
orphan inode handling in ext4.

Orphan inode handling in ext4 is a bottleneck for workloads which heavily
excercise truncate / unlink of small files as they contend on global
s_orphan_mutex (when you have fast enough storage). This patch set implements
new way of handling orphan inodes - instead of using a linked list, we store
inode numbers of orphaned inodes in a file which is possible to implement in a
more scalable manner than linked list manipulations. See description of patch
3/4 for more details.

The patch set achieves significant gains both for a micro benchmark stressing
orphan inode handling (truncating file byte-by-byte, several threads in
parallel) and for reaim creat_clo workload. I'm happy for any review, thoughts,
ideas about the patches. I have also implemented full support in e2fsprogs
which I'll send separately.

								Honza

[1] https://lore.kernel.org/lkml/20210227120804.GB22871@xsang-OptiPlex-9020/

Changes since v2:
* Updated some comments
* Rebased onto 5.13-rc5
* Change orphan file inode from a fixed inode number to inode number stored
  in the superblock

Changes since v1:
* orphan blocks have now magic numbers
* split out orphan handling to a separate source file
* some smaller updates according to review

^ permalink raw reply	[flat|nested] 16+ messages in thread

end of thread, other threads:[~2021-07-08 18:30 UTC | newest]

Thread overview: 16+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-06-16 10:56 [PATCH 0/4 v3] ext4: Speedup orphan file handling Jan Kara
2021-06-16 10:56 ` [PATCH 1/4] ext4: Support for checksumming from journal triggers Jan Kara
2021-06-16 19:56   ` Andreas Dilger
2021-06-17  8:24     ` Jan Kara
2021-06-16 10:56 ` [PATCH 2/4] ext4: Move orphan inode handling into a separate file Jan Kara
2021-06-17  3:24   ` Andreas Dilger
2021-06-17  6:56   ` kernel test robot
2021-06-17 12:40   ` kernel test robot
2021-06-16 10:56 ` [PATCH 3/4] ext4: Speedup ext4 orphan inode handling Jan Kara
2021-06-17  7:44   ` Andreas Dilger
2021-06-17  8:22     ` Jan Kara
2021-06-30 13:25   ` Lukas Czerner
2021-06-30 15:54   ` Darrick J. Wong
2021-06-16 10:56 ` [PATCH 4/4] ext4: Improve scalability of ext4 orphan file handling Jan Kara
2021-06-30 13:46   ` Lukas Czerner
2021-07-08 18:30     ` Jan Kara

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