The patch titled
Subject: lib/group_cpus: relax atomicity requirement in grp_spread_init_one()
has been added to the -mm mm-nonmm-unstable branch. Its filename is
lib-group_cpus-relax-atomicity-requirement-in-grp_spread_init_one.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/lib-group_cpus-relax-atomicity-requirement-in-grp_spread_init_one.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Yury Norov <yury.norov@xxxxxxxxx>
Subject: lib/group_cpus: relax atomicity requirement in grp_spread_init_one()
Date: Thu, 7 Dec 2023 12:38:56 -0800
Because nmsk and irqmsk are stable, extra atomicity is not required.
Link: https://lkml.kernel.org/r/20231207203900.859776-3-yury.norov@xxxxxxxxx
Signed-off-by: Yury Norov <yury.norov@xxxxxxxxx>
Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Cc: Ming Lei <ming.lei@xxxxxxxxxx>
Cc: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/group_cpus.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
--- a/lib/group_cpus.c~lib-group_cpus-relax-atomicity-requirement-in-grp_spread_init_one
+++ a/lib/group_cpus.c
@@ -24,8 +24,8 @@ static void grp_spread_init_one(struct c
if (cpu >= nr_cpu_ids)
return;
- cpumask_clear_cpu(cpu, nmsk);
- cpumask_set_cpu(cpu, irqmsk);
+ __cpumask_clear_cpu(cpu, nmsk);
+ __cpumask_set_cpu(cpu, irqmsk);
cpus_per_grp--;
/* If the cpu has siblings, use them first */
@@ -34,9 +34,8 @@ static void grp_spread_init_one(struct c
sibl = cpumask_next(sibl, siblmsk);
if (sibl >= nr_cpu_ids)
break;
- if (!cpumask_test_and_clear_cpu(sibl, nmsk))
- continue;
- cpumask_set_cpu(sibl, irqmsk);
+ __cpumask_clear_cpu(sibl, nmsk);
+ __cpumask_set_cpu(sibl, irqmsk);
cpus_per_grp--;
}
}
_
Patches currently in -mm which might be from yury.norov@xxxxxxxxx are
cpumask-introduce-for_each_cpu_and_from.patch
lib-group_cpus-relax-atomicity-requirement-in-grp_spread_init_one.patch
lib-group_cpus-optimize-inner-loop-in-grp_spread_init_one.patch
lib-group_cpus-optimize-outer-loop-in-grp_spread_init_one.patch
lib-cgroup_cpusc-dont-zero-cpumasks-in-group_cpus_evenly-on-allocation.patch
lib-group_cpusc-drop-unneeded-cpumask_empty-call-in-__group_cpus_evenly.patch
