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Peter-Jan Gootzen 529395d2ae virtio-fs: add multi-queue support
This commit creates a multi-queue mapping at device bring-up.
The driver first attempts to use the existing MSI-X interrupt
affinities (previously disabled), and if not present, will distribute
the request queues evenly over the CPUs.
If the latter fails as well, all CPUs are mapped to request queue zero.

When a request is handed from FUSE to the virtio-fs device driver, the
driver will use the current CPU to index into the multi-queue mapping
and determine the optimal request queue to use.

We measured the performance of this patch with the fio benchmarking
tool, increasing the number of queues results in a significant speedup
for both read and write operations, demonstrating the effectiveness
of multi-queue support.

Host:
  - Dell PowerEdge R760
  - CPU: Intel(R) Xeon(R) Gold 6438M, 128 cores
  - VM: KVM with 32 cores
Virtio-fs device:
  - BlueField-3 DPU
  - CPU: ARM Cortex-A78AE, 16 cores
  - One thread per queue, each busy polling on one request queue
  - Each queue is 1024 descriptors deep
Workload:
  - fio, sequential read or write, ioengine=libaio, numjobs=32,
    4GiB file per job, iodepth=8, bs=256KiB, runtime=30s
Performance Results:
+===========================+==========+===========+
|     Number of queues      | Fio read | Fio write |
+===========================+==========+===========+
| 1 request queue (GiB/s)   | 6.1     | 4.6        |
+---------------------------+----------+-----------+
| 8 request queues (GiB/s)  | 25.8    | 10.3       |
+---------------------------+----------+-----------+
| 16 request queues (GiB/s) | 30.9    | 19.5       |
+---------------------------+----------+-----------+
| 32 request queue (GiB/s)  | 33.2    | 22.6       |
+---------------------------+----------+-----------+
| Speedup                   | 5.5x    | 5x         |
+---------------=-----------+----------+-----------+

Signed-off-by: Peter-Jan Gootzen <pgootzen@nvidia.com>
Signed-off-by: Yoray Zack <yorayz@nvidia.com>
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-05-10 13:38:14 +02:00
arch - Add a missing memory barrier in the concurrency ID mm switching 2024-04-21 09:39:36 -07:00
block block-6.9-20240420 2024-04-20 11:28:02 -07:00
certs This update includes the following changes: 2023-11-02 16:15:30 -10:00
crypto This push fixes a regression that broke iwd as well as a divide by 2024-03-25 10:48:23 -07:00
Documentation Kernfs bugfix and documentation update for 6.9-rc5 2024-04-21 10:30:21 -07:00
drivers Char/Misc driver fixes for 6.9-rc5 2024-04-21 10:32:58 -07:00
fs virtio-fs: add multi-queue support 2024-05-10 13:38:14 +02:00
include Char/Misc driver fixes for 6.9-rc5 2024-04-21 10:32:58 -07:00
init init/main.c: Fix potential static_command_line memory overflow 2024-04-13 00:59:36 +09:00
io_uring io_uring/net: restore msg_control on sendzc retry 2024-04-08 21:48:41 -06:00
ipc sysctl changes for v6.9-rc1 2024-03-18 14:59:13 -07:00
kernel - Add a missing memory barrier in the concurrency ID mm switching 2024-04-21 09:39:36 -07:00
lib hardening fixes for v6.9-rc5 2024-04-19 14:10:11 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm mm/shmem: inline shmem_is_huge() for disabled transparent hugepages 2024-04-16 15:39:51 -07:00
net netfilter pull request 24-04-18 2024-04-18 13:12:37 +02:00
rust Kbuild updates for v6.9 2024-03-21 14:41:00 -07:00
samples Tracing updates for 6.9: 2024-03-18 15:11:44 -07:00
scripts hardening fixes for v6.9-rc4 2024-04-10 13:31:34 -07:00
security security: Place security_path_post_mknod() where the original IMA call was 2024-04-03 10:21:32 -07:00
sound ALSA: seq: ump: Fix conversion from MIDI2 to MIDI1 UMP messages 2024-04-19 12:07:14 +02:00
tools * Clean up SVM's enter/exit assembly code so that it can be compiled 2024-04-20 11:10:51 -07:00
usr Kbuild updates for v6.8 2024-01-18 17:57:07 -08:00
virt KVM: Drop unused @may_block param from gfn_to_pfn_cache_invalidate_start() 2024-04-11 12:58:53 -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
.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 TTY/Serial driver fixes for 6.9-rc5 2024-04-21 10:27:01 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING
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 TTY/Serial driver fixes for 6.9-rc5 2024-04-21 10:27:01 -07:00
Makefile Linux 6.9-rc5 2024-04-21 12:35:54 -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.