archive mirror
 help / color / mirror / Atom feed
From: Jan Kara <>
To: Ted Tso <>
Cc: <>, Jan Kara <>
Subject: [PATCH 0/4 v3] ext4: Speedup orphan file handling
Date: Wed, 16 Jun 2021 12:56:51 +0200	[thread overview]
Message-ID: <> (raw)


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.



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

             reply	other threads:[~2021-06-16 10:57 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-16 10:56 Jan Kara [this message]
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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \
    --subject='Re: [PATCH 0/4 v3] ext4: Speedup orphan file handling' \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).