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| author | Peter Zijlstra <peterz@infradead.org> | 2021-02-24 11:15:23 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2021-03-06 12:40:21 +0100 |
| commit | 58b1a45086b5f80f2b2842aa7ed0da51a64a302b (patch) | |
| tree | 763139498bda05d3827770839028f5acce5a0c67 /kernel | |
| parent | c20cf065d4a619d394d23290093b1002e27dff86 (diff) | |
| download | linux-next-58b1a45086b5f80f2b2842aa7ed0da51a64a302b.tar.gz | |
sched: Collate affine_move_task() stoppers
The SCA_MIGRATE_ENABLE and task_running() cases are almost identical,
collapse them to avoid further duplication.
Fixes: 6d337eab041d ("sched: Fix migrate_disable() vs set_cpus_allowed_ptr()")
Cc: stable@kernel.org
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210224131355.500108964@infradead.org
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/core.c | 23 |
1 files changed, 8 insertions, 15 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 088e8f492271..84b657f05625 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2239,30 +2239,23 @@ static int affine_move_task(struct rq *rq, struct task_struct *p, struct rq_flag return -EINVAL; } - if (flags & SCA_MIGRATE_ENABLE) { - - refcount_inc(&pending->refs); /* pending->{arg,stop_work} */ - p->migration_flags &= ~MDF_PUSH; - task_rq_unlock(rq, p, rf); - - stop_one_cpu_nowait(cpu_of(rq), migration_cpu_stop, - &pending->arg, &pending->stop_work); - - return 0; - } - if (task_running(rq, p) || p->state == TASK_WAKING) { /* - * Lessen races (and headaches) by delegating - * is_migration_disabled(p) checks to the stopper, which will - * run on the same CPU as said p. + * MIGRATE_ENABLE gets here because 'p == current', but for + * anything else we cannot do is_migration_disabled(), punt + * and have the stopper function handle it all race-free. */ + refcount_inc(&pending->refs); /* pending->{arg,stop_work} */ + if (flags & SCA_MIGRATE_ENABLE) + p->migration_flags &= ~MDF_PUSH; task_rq_unlock(rq, p, rf); stop_one_cpu_nowait(cpu_of(rq), migration_cpu_stop, &pending->arg, &pending->stop_work); + if (flags & SCA_MIGRATE_ENABLE) + return 0; } else { if (!is_migration_disabled(p)) { |