diff options
Diffstat (limited to 'kernel/time/tick-sched.c')
| -rw-r--r-- | kernel/time/tick-sched.c | 50 |
1 files changed, 40 insertions, 10 deletions
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 566ad5bd83e9..2d76c91b85de 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -999,6 +999,45 @@ static void tick_nohz_full_update_tick(struct tick_sched *ts) __tick_nohz_full_update_tick(ts, ktime_get()); } +/* + * A pending softirq outside an IRQ (or softirq disabled section) context + * should be waiting for ksoftirqd to handle it. Therefore we shouldn't + * reach here due to the need_resched() early check in can_stop_idle_tick(). + * + * However if we are between CPUHP_AP_SMPBOOT_THREADS and CPU_TEARDOWN_CPU on the + * cpu_down() process, softirqs can still be raised while ksoftirqd is parked, + * triggering the below since wakep_softirqd() is ignored. + * + */ +static bool report_idle_softirq(void) +{ + static int ratelimit; + unsigned int pending = local_softirq_pending(); + + if (likely(!pending)) + return false; + + /* Some softirqs claim to be safe against hotplug and ksoftirqd parking */ + if (!cpu_active(smp_processor_id())) { + pending &= ~SOFTIRQ_HOTPLUG_SAFE_MASK; + if (!pending) + return false; + } + + if (ratelimit < 10) + return false; + + /* On RT, softirqs handling may be waiting on some lock */ + if (!local_bh_blocked()) + return false; + + pr_warn("NOHZ tick-stop error: local softirq work is pending, handler #%02x!!!\n", + pending); + ratelimit++; + + return true; +} + static bool can_stop_idle_tick(int cpu, struct tick_sched *ts) { /* @@ -1025,17 +1064,8 @@ static bool can_stop_idle_tick(int cpu, struct tick_sched *ts) if (need_resched()) return false; - if (unlikely(local_softirq_pending())) { - static int ratelimit; - - if (ratelimit < 10 && !local_bh_blocked() && - (local_softirq_pending() & SOFTIRQ_STOP_IDLE_MASK)) { - pr_warn("NOHZ tick-stop error: Non-RCU local softirq work is pending, handler #%02x!!!\n", - (unsigned int) local_softirq_pending()); - ratelimit++; - } + if (unlikely(report_idle_softirq())) return false; - } if (tick_nohz_full_enabled()) { /* |