From: Yury Norov <yury.norov@gmail.com>
To: linux-kernel@vger.kernel.org,
"David S. Miller" <davem@davemloft.net>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Barry Song <baohua@kernel.org>, Ben Segall <bsegall@google.com>,
haniel Bristot de Oliveira <bristot@redhat.com>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Gal Pressman <gal@nvidia.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Heiko Carstens <hca@linux.ibm.com>,
Ingo Molnar <mingo@redhat.com>, Jakub Kicinski <kuba@kernel.org>,
Jason Gunthorpe <jgg@nvidia.com>,
Jesse Brandeburg <jesse.brandeburg@intel.com>,
Jonathan Cameron <Jonathan.Cameron@huawei.com>,
Juri Lelli <juri.lelli@redhat.com>,
Leon Romanovsky <leonro@nvidia.com>, Mel Gorman <mgorman@suse.de>,
Peter Zijlstra <peterz@infradead.org>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Saeed Mahameed <saeedm@nvidia.com>,
Steven Rostedt <rostedt@goodmis.org>,
Tariq Toukan <tariqt@nvidia.com>,
Tariq Toukan <ttoukan.linux@gmail.com>,
Tony Luck <tony.luck@intel.com>,
Valentin Schneider <vschneid@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>
Cc: Yury Norov <yury.norov@gmail.com>,
linux-crypto@vger.kernel.org, netdev@vger.kernel.org,
linux-rdma@vger.kernel.org
Subject: [PATCH v2 0/4] cpumask: improve on cpumask_local_spread() locality
Date: Sat, 12 Nov 2022 11:09:42 -0800 [thread overview]
Message-ID: <20221112190946.728270-1-yury.norov@gmail.com> (raw)
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 series is inspired by Tariq Toukan and Valentin Schneider's "net/mlx5e:
Improve remote NUMA preferences used for the IRQ affinity hints"
https://patchwork.kernel.org/project/netdevbpf/patch/20220728191203.4055-3-tariqt@nvidia.com/
According to their measurements, for mlx5e:
Bottleneck in RX side is released, reached linerate (~1.8x speedup).
~30% less cpu util on TX.
This patch makes cpumask_local_spread() traversing CPUs based on NUMA
distance, just as well, and I expect comparabale improvement for its
users, as in case of mlx5e.
I tested new behavior on my VM with the following NUMA configuration:
root@debian:~# numactl -H
available: 4 nodes (0-3)
node 0 cpus: 0 1 2 3
node 0 size: 3869 MB
node 0 free: 3740 MB
node 1 cpus: 4 5
node 1 size: 1969 MB
node 1 free: 1937 MB
node 2 cpus: 6 7
node 2 size: 1967 MB
node 2 free: 1873 MB
node 3 cpus: 8 9 10 11 12 13 14 15
node 3 size: 7842 MB
node 3 free: 7723 MB
node distances:
node 0 1 2 3
0: 10 50 30 70
1: 50 10 70 30
2: 30 70 10 50
3: 70 30 50 10
And the cpumask_local_spread() for each node and offset traversing looks
like this:
node 0: 0 1 2 3 6 7 4 5 8 9 10 11 12 13 14 15
node 1: 4 5 8 9 10 11 12 13 14 15 0 1 2 3 6 7
node 2: 6 7 0 1 2 3 8 9 10 11 12 13 14 15 4 5
node 3: 8 9 10 11 12 13 14 15 4 5 6 7 0 1 2 3
v1: https://lore.kernel.org/lkml/20221111040027.621646-5-yury.norov@gmail.com/T/
v2:
- use bsearch() in sched_numa_find_nth_cpu();
- fix missing 'static inline' in 3rd patch.
Yury Norov (4):
lib/find: introduce find_nth_and_andnot_bit
cpumask: introduce cpumask_nth_and_andnot
sched: add sched_numa_find_nth_cpu()
cpumask: improve on cpumask_local_spread() locality
include/linux/cpumask.h | 20 +++++++++++++++
include/linux/find.h | 33 ++++++++++++++++++++++++
include/linux/topology.h | 8 ++++++
kernel/sched/topology.c | 55 ++++++++++++++++++++++++++++++++++++++++
lib/cpumask.c | 12 ++-------
lib/find_bit.c | 9 +++++++
6 files changed, 127 insertions(+), 10 deletions(-)
--
2.34.1
next reply other threads:[~2022-11-12 19:10 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-12 19:09 Yury Norov [this message]
2022-11-12 19:09 ` [PATCH v2 1/4] lib/find: introduce find_nth_and_andnot_bit Yury Norov
2022-11-12 19:09 ` [PATCH v2 2/4] cpumask: introduce cpumask_nth_and_andnot Yury Norov
2022-11-12 19:09 ` [PATCH v2 3/4] sched: add sched_numa_find_nth_cpu() Yury Norov
2022-11-14 14:32 ` Andy Shevchenko
2022-11-14 15:02 ` Andy Shevchenko
2022-12-08 2:55 ` Yury Norov
2022-11-15 17:25 ` Valentin Schneider
2022-11-12 19:09 ` [PATCH v2 4/4] cpumask: improve on cpumask_local_spread() locality Yury Norov
2022-11-15 17:24 ` [PATCH v2 0/4] " Valentin Schneider
2022-11-15 18:32 ` Yury Norov
2022-11-17 12:23 ` Valentin Schneider
2022-11-28 6:39 ` Tariq Toukan
2022-11-30 1:47 ` Yury Norov
2022-12-07 12:53 ` Tariq Toukan
2022-12-07 20:45 ` Yury Norov
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