diff options
| author | Will Deacon <will@kernel.org> | 2021-07-30 13:24:29 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2021-08-20 12:32:58 +0200 |
| commit | d4b96fb92ae7fe7533e11e662504d96161928575 (patch) | |
| tree | 74fc95552e234a0d56e281fab055c865b0a62b8f /kernel/cgroup | |
| parent | sched: Introduce task_cpu_possible_mask() to limit fallback rq selection (diff) | |
| download | linux-d4b96fb92ae7fe7533e11e662504d96161928575.tar.xz linux-d4b96fb92ae7fe7533e11e662504d96161928575.zip | |
cpuset: Don't use the cpu_possible_mask as a last resort for cgroup v1
If the scheduler cannot find an allowed CPU for a task,
cpuset_cpus_allowed_fallback() will widen the affinity to cpu_possible_mask
if cgroup v1 is in use.
In preparation for allowing architectures to provide their own fallback
mask, just return early if we're either using cgroup v1 or we're using
cgroup v2 with a mask that contains invalid CPUs. This will allow
select_fallback_rq() to figure out the mask by itself.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Quentin Perret <qperret@google.com>
Link: https://lkml.kernel.org/r/20210730112443.23245-3-will@kernel.org
Diffstat (limited to 'kernel/cgroup')
| -rw-r--r-- | kernel/cgroup/cpuset.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index adb5190c4429..a8693783f385 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -3322,9 +3322,13 @@ void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask) void cpuset_cpus_allowed_fallback(struct task_struct *tsk) { + const struct cpumask *possible_mask = task_cpu_possible_mask(tsk); + const struct cpumask *cs_mask; + rcu_read_lock(); - do_set_cpus_allowed(tsk, is_in_v2_mode() ? - task_cs(tsk)->cpus_allowed : cpu_possible_mask); + cs_mask = task_cs(tsk)->cpus_allowed; + if (is_in_v2_mode() && cpumask_subset(cs_mask, possible_mask)) + do_set_cpus_allowed(tsk, cs_mask); rcu_read_unlock(); /* |