Re: [PATCH v3 07/14] sched: Introduce restrict_cpus_allowed_ptr() to limit task CPU affinity
From: Quentin Perret <hidden>
Date: 2020-11-19 09:18:48
Also in:
linux-arch, lkml
Hey Will, On Friday 13 Nov 2020 at 09:37:12 (+0000), Will Deacon wrote:
-static int __set_cpus_allowed_ptr(struct task_struct *p,
- const struct cpumask *new_mask, bool check)
+static int __set_cpus_allowed_ptr_locked(struct task_struct *p,
+ const struct cpumask *new_mask,
+ bool check,
+ struct rq *rq,
+ struct rq_flags *rf)
{
const struct cpumask *cpu_valid_mask = cpu_active_mask;
unsigned int dest_cpu;
- struct rq_flags rf;
- struct rq *rq;
int ret = 0;Should we have a lockdep assertion here?
quoted hunk ↗ jump to hunk
- rq = task_rq_lock(p, &rf); update_rq_clock(rq); if (p->flags & PF_KTHREAD) {@@ -1929,7 +1923,7 @@ static int __set_cpus_allowed_ptr(struct task_struct *p, if (task_running(rq, p) || p->state == TASK_WAKING) { struct migration_arg arg = { p, dest_cpu }; /* Need help from migration thread: drop lock and wait. */ - task_rq_unlock(rq, p, &rf); + task_rq_unlock(rq, p, rf); stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg); return 0; } else if (task_on_rq_queued(p)) {@@ -1937,20 +1931,69 @@ static int __set_cpus_allowed_ptr(struct task_struct *p, * OK, since we're going to drop the lock immediately * afterwards anyway. */ - rq = move_queued_task(rq, &rf, p, dest_cpu); + rq = move_queued_task(rq, rf, p, dest_cpu); } out: - task_rq_unlock(rq, p, &rf); + task_rq_unlock(rq, p, rf);
And that's a little odd to have here no? Can we move it back on the caller's side?
return ret; }
Thanks, Quentin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel