In the previous code, dbuf_evict_thread() would called dbuf_evict_one() in a look while dbuf_cache_above_lowater(). dbuf_evict_one() would select a random sublist from the dbuf cache, then walk it from the tail forward, attempting to acquire the lock on each object until it succeeded, then evict that object and return. As the name suggests, it would evict only a single object from the cache. However, evicting one object is not likely to bring us below the desired low water mark, so dbuf_evict_one() will be called again, where it will loop over all of the same busy objects again, until it founds one it can evict. This has been replaced with dbuf_evict_many() which takes a specific sublist as a parameter, as well as a desired amount of data to evict. It then walks the sublist from the tail forward, evicting what it can until the number of bytes evicted satisfies the input parameter or the head of the sublist is reached. The dbuf_evict_thread now runs is parallel as well, allowing it to keep up with demand more easily. For the dbuf cache, if the single thread was not able to keep up, ZFS would shift the work of evicting some items to each incoming I/O thread. While that is still the case it should be seen much less often now that dbuf_evict is more efficient and no longer bottlenecked to a single thread. Sponsored-by: Expensify, Inc. Sponsored-by: Klara, Inc. Co-authored-by: Allan Jude <allan@klarasystems.com> Co-authored-by: Mateusz Piotrowski <mateusz.piotrowski@klarasystems.com> Signed-off-by: Alexander Stetsenko <alex.stetsenko@gmail.com> Signed-off-by: Allan Jude <allan@klarasystems.com> Signed-off-by: Mateusz Piotrowski <mateusz.piotrowski@klarasystems.com> |
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cmd | ||
config | ||
contrib | ||
etc | ||
include | ||
lib | ||
man | ||
module | ||
rpm | ||
scripts | ||
tests | ||
udev | ||
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AUTHORS | ||
CODE_OF_CONDUCT.md | ||
COPYRIGHT | ||
LICENSE | ||
META | ||
Makefile.am | ||
NEWS | ||
NOTICE | ||
README.md | ||
RELEASES.md | ||
TEST | ||
autogen.sh | ||
configure.ac | ||
copy-builtin | ||
zfs.release.in |
README.md
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.
Official Resources
- Documentation - for using and developing this repo
- ZoL Site - Linux release info & links
- Mailing lists
- OpenZFS site - for conference videos and info on other platforms (illumos, OSX, Windows, etc)
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 13.0-RELEASE.