mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-04-26 15:43:06 -04:00
cc74ca303a
Yury Norov says: ==================== sched: cpumask: improve on cpumask_local_spread() locality cpumask_local_spread() currently checks local node for presence of i'th CPU, and then if it finds nothing makes a flat search among all non-local CPUs. We can do it better by checking CPUs per NUMA hops. This has significant performance implications on NUMA machines, for example when using NUMA-aware allocated memory together with NUMA-aware IRQ affinity hints. Performance tests from patch 8 of this series for mellanox network driver show: TCP multi-stream, using 16 iperf3 instances pinned to 16 cores (with aRFS on). Active cores: 64,65,72,73,80,81,88,89,96,97,104,105,112,113,120,121 +-------------------------+-----------+------------------+------------------+ | | BW (Gbps) | TX side CPU util | RX side CPU util | +-------------------------+-----------+------------------+------------------+ | Baseline | 52.3 | 6.4 % | 17.9 % | +-------------------------+-----------+------------------+------------------+ | Applied on TX side only | 52.6 | 5.2 % | 18.5 % | +-------------------------+-----------+------------------+------------------+ | Applied on RX side only | 94.9 | 11.9 % | 27.2 % | +-------------------------+-----------+------------------+------------------+ | Applied on both sides | 95.1 | 8.4 % | 27.3 % | +-------------------------+-----------+------------------+------------------+ Bottleneck in RX side is released, reached linerate (~1.8x speedup). ~30% less cpu util on TX. ==================== Link: https://lore.kernel.org/r/20230121042436.2661843-1-yury.norov@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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 Restructured Text 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.