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Caleb Sander Mateos b83db10996 mlx5/core: relax memory barrier in eq_update_ci()
The memory barrier in eq_update_ci() after the doorbell write is a
significant hot spot in mlx5_eq_comp_int(). Under heavy TCP load, we see
3% of CPU time spent on the mfence instruction.

98df6d5b87 ("net/mlx5: A write memory barrier is sufficient in EQ ci
update") already relaxed the full memory barrier to just a write barrier
in mlx5_eq_update_ci(), which duplicates eq_update_ci(). So replace mb()
with wmb() in eq_update_ci() too.

On strongly ordered architectures, no barrier is actually needed because
the MMIO writes to the doorbell register are guaranteed to appear to the
device in the order they were made. However, the kernel's ordered MMIO
primitive writel() lacks a convenient big-endian interface.
Therefore, we opt to stick with __raw_writel() + a barrier.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Parav Pandit <parav@nvidia.com>
Acked-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20241107183054.2443218-1-csander@purestorage.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-11 14:13:44 -08:00
arch xtensa: remove the get_order() implementation 2024-11-11 10:56:27 -08:00
block block-6.12-20241101 2024-11-01 13:41:55 -10:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto This push fixes the following issues: 2024-10-16 08:42:54 -07:00
Documentation neighbour: Create netdev->neighbour association 2024-11-09 13:22:57 -08:00
drivers mlx5/core: relax memory barrier in eq_update_ci() 2024-11-11 14:13:44 -08:00
fs Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-11-07 13:44:16 -08:00
include mm: page_frag: reuse existing space for 'size' and 'pfmemalloc' 2024-11-11 10:56:27 -08:00
init cfi: fix conditions for HAVE_CFI_ICALL_NORMALIZE_INTEGERS 2024-10-13 22:23:13 +02:00
io_uring io_uring/rw: fix missing NOWAIT check for O_DIRECT start write 2024-10-31 08:21:02 -06:00
ipc struct fd layout change (and conversion to accessor helpers) 2024-09-23 09:35:36 -07:00
kernel Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-11-07 13:44:16 -08:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-11-07 13:44:16 -08:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm mm: page_frag: use __alloc_pages() to replace alloc_pages_node() 2024-11-11 10:56:27 -08:00
net mm: page_frag: avoid caller accessing 'page_frag_cache' directly 2024-11-11 10:56:27 -08:00
rust Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-10-21 09:14:18 +02:00
samples [tree-wide] finally take no_llseek out 2024-09-27 08:18:43 -07:00
scripts Kbuild fixes for v6.12 (2nd) 2024-11-03 08:29:02 -10:00
security KEYS: trusted: dcp: fix NULL dereference in AEAD crypto operation 2024-11-04 21:24:24 +02:00
sound ALSA: hda/realtek: Fix headset mic on TUXEDO Stellaris 16 Gen6 mb1 2024-10-30 14:46:59 +01:00
tools selftests: netdevsim: add ethtool features to macsec offload tests 2024-11-11 14:12:21 -08:00
usr initramfs: shorten cmd_initfs in usr/Makefile 2024-07-16 01:07:52 +09:00
virt ARM64: 2024-10-21 11:22:04 -07:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.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 updates for v6.12 2024-09-24 13:02:06 -07:00
.mailmap .mailmap: update e-mail address for Eugen Hristev 2024-10-31 20:27:04 -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: Remove self from DSA entry 2024-11-03 12:52:38 -08:00
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 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-11-07 13:44:16 -08:00
Makefile Linux 6.12-rc6 2024-11-03 14:05:52 -10:00
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.