No description
  • C 96.8%
  • Assembly 0.9%
  • Rust 0.7%
  • Shell 0.6%
  • Python 0.5%
  • Other 0.3%
Find a file
Thomas Song f227345f0a nvme-multipath: implement "queue-depth" iopolicy
The round-robin path selector is inefficient in cases where there is a
difference in latency between paths.  In the presence of one or more
high latency paths the round-robin selector continues to use the high
latency path equally. This results in a bias towards the highest latency
path and can cause a significant decrease in overall performance as IOs
pile on the highest latency path. This problem is acute with NVMe-oF
controllers.

The queue-depth path selector sends I/O down the path with the lowest
number of requests in its request queue. Paths with lower latency will
clear requests more quickly and have less requests queued compared to
higher latency paths. The goal of this path selector is to make more use
of lower latency paths which will bring down overall IO latency and
increase throughput and performance.

Signed-off-by: Thomas Song <tsong@purestorage.com>
[emilne: commandeered patch developed by Thomas Song @ Pure Storage]
Co-developed-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Ewan D. Milne <emilne@redhat.com>
Co-developed-by: John Meneghini <jmeneghi@redhat.com>
Signed-off-by: John Meneghini <jmeneghi@redhat.com>
Link: https://lore.kernel.org/linux-nvme/20240509202929.831680-1-jmeneghi@redhat.com/
Tested-by: Marco Patalano <mpatalan@redhat.com>
Tested-by: Jyoti Rani <jrani@purestorage.com>
Tested-by: John Meneghini <jmeneghi@redhat.com>
Reviewed-by: Randy Jennings <randyj@purestorage.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
History 2024-07-02 06:47:19 -07:00
arch block: move the nonrot flag to queue_limits 2024-06-19 07:58:28 -06:00
block block: Fix blk_validate_atomic_write_limits() build for arm32 2024-06-21 12:31:55 -06:00
certs kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-10 04:34:52 +09:00
crypto This push fixes a bug in the new ecc P521 code as well as a buggy 2024-05-20 08:47:54 -07:00
Documentation block: Add core atomic write support 2024-06-20 15:19:17 -06:00
drivers nvme-multipath: implement "queue-depth" iopolicy 2024-07-02 06:47:19 -07:00
fs block: Add atomic write support for statx 2024-06-20 15:19:17 -06:00
include nvme-pci: do not directly handle subsys reset fallout 2024-06-26 07:02:22 -07:00
init Driver core changes for 6.10-rc1 2024-05-22 12:13:40 -07:00
io_uring fs: Initial atomic write support 2024-06-20 15:19:17 -06:00
ipc Mainly singleton patches, documented in their respective changelogs. 2024-05-19 14:02:03 -07:00
kernel Fix race between perf_event_free_task() and perf_event_release_kernel() 2024-06-08 09:26:59 -07:00
lib Including fixes from BPF and big collection of fixes for WiFi core 2024-06-06 09:55:27 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm mm: fix xyz_noprof functions calling profiled functions 2024-06-05 19:19:26 -07:00
net nfsd-6.10 fixes: 2024-06-07 15:07:57 -07:00
rust rust: block: do not use removed queue flag API 2024-06-20 06:54:48 -06:00
samples tracing/treewide: Remove second parameter of __assign_str() 2024-05-22 20:14:47 -04:00
scripts Kbuild fixes for v6.10 (second) 2024-06-08 10:12:33 -07:00
security tomoyo: update project links 2024-06-03 22:43:11 +09:00
sound ALSA: seq: ump: Fix swapped song position pointer data 2024-05-31 09:51:44 +02:00
tools perf tools fixes for v6.10: 2nd batch 2024-06-09 09:04:51 -07:00
usr kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-10 04:34:52 +09:00
virt The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
.clang-format clang-format: Update with v6.7-rc4's for_each macro list 2023-12-08 23:54:38 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig Add .editorconfig file for basic formatting 2023-12-28 16:22:47 +09:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: create a list of all built DTB files 2024-02-19 18:20:39 +09:00
.mailmap mailmap: add entry for Weiwen Hu 2024-06-24 12:53:42 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Drop Gustavo Pimentel as PCI DWC Maintainer 2024-03-27 13:41:02 -05:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: add entry for Rust block device driver API 2024-06-14 07:45:04 -06:00
Makefile Linux 6.10-rc3 2024-06-09 14:19:43 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.