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Shaan Nobee 9e5a297de6 Speed up WB_SYNC_NONE when a WB_SYNC_ALL occurs simultaneously
Page writebacks with WB_SYNC_NONE can take several seconds to complete
since they wait for the transaction group to close before being
committed. This is usually not a problem since the caller does not
need to wait. However, if we're simultaneously doing a writeback
with WB_SYNC_ALL (e.g via msync), the latter can block for several
seconds (up to zfs_txg_timeout) due to the active WB_SYNC_NONE
writeback since it needs to wait for the transaction to complete
and the PG_writeback bit to be cleared.

This commit deals with 2 cases:

- No page writeback is active. A WB_SYNC_ALL page writeback starts
  and even completes. But when it's about to check if the PG_writeback
  bit has been cleared, another writeback with WB_SYNC_NONE starts.
  The sync page writeback ends up waiting for the non-sync page
  writeback to complete.

- A page writeback with WB_SYNC_NONE is already active when a
  WB_SYNC_ALL writeback starts. The WB_SYNC_ALL writeback ends up
  waiting for the WB_SYNC_NONE writeback.

The fix works by carefully keeping track of active sync/non-sync
writebacks and committing when beneficial.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Shaan Nobee <sniper111@gmail.com>
Closes #12662
Closes #12790
2023-06-05 10:59:02 -07:00
.github Update workflows 2023-03-09 18:46:36 -08:00
cmd Storage device expansion "silently" fails on degraded vdev 2023-05-26 10:12:57 -07:00
config Removed Python 2 and Python 3.5- support 2023-04-13 15:59:45 -07:00
contrib Revert "initramfs: use mount.zfs instead of mount" 2023-06-01 08:30:54 -07:00
etc systemd: set restart=always for zfs-zed.service 2023-01-19 12:50:42 -08:00
include Speed up WB_SYNC_NONE when a WB_SYNC_ALL occurs simultaneously 2023-06-05 10:59:02 -07:00
lib Refine special_small_blocks property validation 2023-05-27 18:23:33 -07:00
man Add the ability to uninitialize 2023-05-26 10:09:04 -07:00
module Speed up WB_SYNC_NONE when a WB_SYNC_ALL occurs simultaneously 2023-06-05 10:59:02 -07:00
rpm Removed Python 2 and Python 3.5- support 2023-04-13 15:59:45 -07:00
scripts ZTS: Log test name to /dev/kmsg on Linux 2023-04-03 13:50:02 -07:00
tests Speed up WB_SYNC_NONE when a WB_SYNC_ALL occurs simultaneously 2023-06-05 10:59:02 -07:00
udev Udev rules: use match (==) rather than assign (=) for PROGRAM 2021-09-14 12:23:10 -07:00
.editorconfig Add an .editorconfig; document git whitespace settings 2020-01-27 13:32:52 -08:00
.gitignore Add FreeBSD support to OpenZFS 2020-04-14 11:36:28 -07:00
.gitmodules .gitmodules: link to openzfs github repository 2021-04-14 13:23:08 -07:00
AUTHORS Add zstd support to zfs 2020-08-20 10:30:06 -07:00
autogen.sh Cause autogen.sh to fail if autoreconf fails 2018-07-06 09:27:37 -07:00
CODE_OF_CONDUCT.md Documentation corrections 2023-01-19 12:50:42 -08:00
configure.ac Speed up WB_SYNC_NONE when a WB_SYNC_ALL occurs simultaneously 2023-06-05 10:59:02 -07:00
copy-builtin copy-builtin: posix conformance 2021-05-10 12:18:54 -07:00
COPYRIGHT Fix typos 2020-06-09 21:24:09 -07:00
LICENSE Update build system and packaging 2018-05-29 16:00:33 -07:00
Makefile.am config: check for parallel(1), use it for cstyle 2022-09-14 11:23:25 -07:00
META Tag zfs-2.1.11 2023-04-18 11:44:34 -07:00
NEWS Fix NEWS file 2020-08-26 21:44:41 -07:00
NOTICE Update build system and packaging 2018-05-29 16:00:33 -07:00
README.md README: Update OpenZFS website url 2022-02-16 17:58:55 -08:00
RELEASES.md Add RELEASES.md file 2021-04-07 13:26:58 -07:00
TEST Remove CI builder customization from TEST 2020-03-16 10:46:03 -07:00
zfs.release.in Move zfs.release generation to configure step 2012-07-12 12:22:51 -07:00

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OpenZFS is an advanced file system and volume manager which was originally developed for Solaris and is now maintained by the OpenZFS community. This repository contains the code for running OpenZFS on Linux and FreeBSD.

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Official Resources

Installation

Full documentation for installing OpenZFS on your favorite operating system can be found at the Getting Started Page.

Contribute & Develop

We have a separate document with contribution guidelines.

We have a Code of Conduct.

Release

OpenZFS is released under a CDDL license. For more details see the NOTICE, LICENSE and COPYRIGHT files; UCRL-CODE-235197

Supported Kernels

  • The META file contains the officially recognized supported Linux kernel versions.
  • Supported FreeBSD versions are any supported branches and releases starting from 12.2-RELEASE.