diff options
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/core.c | 2 | ||||
| -rw-r--r-- | kernel/sched/ext.c | 11 | ||||
| -rw-r--r-- | kernel/sched/sched.h | 25 |
3 files changed, 30 insertions, 8 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 9aecd914ac69..67189907214d 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7285,7 +7285,7 @@ out_unlock: #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) int __sched __cond_resched(void) { - if (should_resched(0)) { + if (should_resched(0) && !irqs_disabled()) { preempt_schedule_common(); return 1; } diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index 5a81d9a1e31f..0f1da199cfc7 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -3117,7 +3117,6 @@ static struct task_struct *pick_task_scx(struct rq *rq) { struct task_struct *prev = rq->curr; struct task_struct *p; - bool prev_on_scx = prev->sched_class == &ext_sched_class; bool keep_prev = rq->scx.flags & SCX_RQ_BAL_KEEP; bool kick_idle = false; @@ -3137,14 +3136,18 @@ static struct task_struct *pick_task_scx(struct rq *rq) * if pick_task_scx() is called without preceding balance_scx(). */ if (unlikely(rq->scx.flags & SCX_RQ_BAL_PENDING)) { - if (prev_on_scx) { + if (prev->scx.flags & SCX_TASK_QUEUED) { keep_prev = true; } else { keep_prev = false; kick_idle = true; } - } else if (unlikely(keep_prev && !prev_on_scx)) { - /* only allowed during transitions */ + } else if (unlikely(keep_prev && + prev->sched_class != &ext_sched_class)) { + /* + * Can happen while enabling as SCX_RQ_BAL_PENDING assertion is + * conditional on scx_enabled() and may have been skipped. + */ WARN_ON_ONCE(scx_ops_enable_state() == SCX_OPS_ENABLED); keep_prev = false; } diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index b93c8c3dc05a..c8512a9fb022 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -3698,10 +3698,28 @@ static inline int __mm_cid_try_get(struct task_struct *t, struct mm_struct *mm) { struct cpumask *cidmask = mm_cidmask(mm); struct mm_cid __percpu *pcpu_cid = mm->pcpu_cid; - int cid = __this_cpu_read(pcpu_cid->recent_cid); + int cid, max_nr_cid, allowed_max_nr_cid; + /* + * After shrinking the number of threads or reducing the number + * of allowed cpus, reduce the value of max_nr_cid so expansion + * of cid allocation will preserve cache locality if the number + * of threads or allowed cpus increase again. + */ + max_nr_cid = atomic_read(&mm->max_nr_cid); + while ((allowed_max_nr_cid = min_t(int, READ_ONCE(mm->nr_cpus_allowed), + atomic_read(&mm->mm_users))), + max_nr_cid > allowed_max_nr_cid) { + /* atomic_try_cmpxchg loads previous mm->max_nr_cid into max_nr_cid. */ + if (atomic_try_cmpxchg(&mm->max_nr_cid, &max_nr_cid, allowed_max_nr_cid)) { + max_nr_cid = allowed_max_nr_cid; + break; + } + } /* Try to re-use recent cid. This improves cache locality. */ - if (!mm_cid_is_unset(cid) && !cpumask_test_and_set_cpu(cid, cidmask)) + cid = __this_cpu_read(pcpu_cid->recent_cid); + if (!mm_cid_is_unset(cid) && cid < max_nr_cid && + !cpumask_test_and_set_cpu(cid, cidmask)) return cid; /* * Expand cid allocation if the maximum number of concurrency @@ -3709,8 +3727,9 @@ static inline int __mm_cid_try_get(struct task_struct *t, struct mm_struct *mm) * and number of threads. Expanding cid allocation as much as * possible improves cache locality. */ - cid = atomic_read(&mm->max_nr_cid); + cid = max_nr_cid; while (cid < READ_ONCE(mm->nr_cpus_allowed) && cid < atomic_read(&mm->mm_users)) { + /* atomic_try_cmpxchg loads previous mm->max_nr_cid into cid. */ if (!atomic_try_cmpxchg(&mm->max_nr_cid, &cid, cid + 1)) continue; if (!cpumask_test_and_set_cpu(cid, cidmask)) |