diff options
| -rw-r--r-- | kernel/sched/core.c | 4 | ||||
| -rw-r--r-- | kernel/sched/fair.c | 52 | ||||
| -rw-r--r-- | kernel/sched/sched.h | 4 |
3 files changed, 41 insertions, 19 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 96ad1c003d74..69c9a6b07b61 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -583,7 +583,7 @@ static inline bool got_nohz_idle_kick(void) { int cpu = smp_processor_id(); - if (!(atomic_read(nohz_flags(cpu)) & NOHZ_BALANCE_KICK)) + if (!(atomic_read(nohz_flags(cpu)) & NOHZ_KICK_MASK)) return false; if (idle_cpu(cpu) && !need_resched()) @@ -593,7 +593,7 @@ static inline bool got_nohz_idle_kick(void) * We can't run Idle Load Balance on this CPU for this time so we * cancel it and clear NOHZ_BALANCE_KICK */ - atomic_andnot(NOHZ_BALANCE_KICK, nohz_flags(cpu)); + atomic_andnot(NOHZ_KICK_MASK, nohz_flags(cpu)); return false; } diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 5d150478dd58..fc058967c999 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -9082,8 +9082,8 @@ static void nohz_balancer_kick(void) if (ilb_cpu >= nr_cpu_ids) return; - flags = atomic_fetch_or(NOHZ_BALANCE_KICK, nohz_flags(ilb_cpu)); - if (flags & NOHZ_BALANCE_KICK) + flags = atomic_fetch_or(NOHZ_KICK_MASK, nohz_flags(ilb_cpu)); + if (flags & NOHZ_KICK_MASK) return; /* * Use smp_send_reschedule() instead of resched_cpu(). @@ -9202,8 +9202,6 @@ static void rebalance_domains(struct rq *rq, enum cpu_idle_type idle) int need_serialize, need_decay = 0; u64 max_cost = 0; - update_blocked_averages(cpu); - rcu_read_lock(); for_each_domain(cpu, sd) { /* @@ -9298,20 +9296,27 @@ out: * In CONFIG_NO_HZ_COMMON case, the idle balance kickee will do the * rebalancing for all the CPUs for whom scheduler ticks are stopped. */ -static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle) +static bool nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle) { - int this_cpu = this_rq->cpu; - struct rq *rq; - int balance_cpu; /* Earliest time when we have to do rebalance again */ unsigned long next_balance = jiffies + 60*HZ; int update_next_balance = 0; + int this_cpu = this_rq->cpu; + unsigned int flags; + int balance_cpu; + struct rq *rq; - if (!(atomic_read(nohz_flags(this_cpu)) & NOHZ_BALANCE_KICK)) - return; + if (!(atomic_read(nohz_flags(this_cpu)) & NOHZ_KICK_MASK)) + return false; - if (idle != CPU_IDLE) - goto end; + if (idle != CPU_IDLE) { + atomic_andnot(NOHZ_KICK_MASK, nohz_flags(this_cpu)); + return false; + } + + flags = atomic_fetch_andnot(NOHZ_KICK_MASK, nohz_flags(this_cpu)); + + SCHED_WARN_ON((flags & NOHZ_KICK_MASK) == NOHZ_BALANCE_KICK); for_each_cpu(balance_cpu, nohz.idle_cpus_mask) { if (balance_cpu == this_cpu || !idle_cpu(balance_cpu)) @@ -9339,7 +9344,9 @@ static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle) cpu_load_update_idle(rq); rq_unlock_irq(rq, &rf); - rebalance_domains(rq, CPU_IDLE); + update_blocked_averages(rq->cpu); + if (flags & NOHZ_BALANCE_KICK) + rebalance_domains(rq, CPU_IDLE); } if (time_after(next_balance, rq->next_balance)) { @@ -9348,6 +9355,10 @@ static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle) } } + update_blocked_averages(this_cpu); + if (flags & NOHZ_BALANCE_KICK) + rebalance_domains(this_rq, CPU_IDLE); + /* * next_balance will be updated only when there is a need. * When the CPU is attached to null domain for ex, it will not be @@ -9355,8 +9366,8 @@ static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle) */ if (likely(update_next_balance)) nohz.next_balance = next_balance; -end: - atomic_andnot(NOHZ_BALANCE_KICK, nohz_flags(this_cpu)); + + return true; } /* @@ -9443,7 +9454,10 @@ unlock: return kick; } #else -static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle) { } +static bool nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle) +{ + return false; +} #endif /* @@ -9464,7 +9478,11 @@ static __latent_entropy void run_rebalance_domains(struct softirq_action *h) * load balance only within the local sched_domain hierarchy * and abort nohz_idle_balance altogether if we pull some load. */ - nohz_idle_balance(this_rq, idle); + if (nohz_idle_balance(this_rq, idle)) + return; + + /* normal load balance */ + update_blocked_averages(this_rq->cpu); rebalance_domains(this_rq, idle); } diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index d98e761b962f..5295f274053b 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -2036,9 +2036,13 @@ extern void cfs_bandwidth_usage_dec(void); #ifdef CONFIG_NO_HZ_COMMON #define NOHZ_TICK_STOPPED_BIT 0 #define NOHZ_BALANCE_KICK_BIT 1 +#define NOHZ_STATS_KICK_BIT 2 #define NOHZ_TICK_STOPPED BIT(NOHZ_TICK_STOPPED_BIT) #define NOHZ_BALANCE_KICK BIT(NOHZ_BALANCE_KICK_BIT) +#define NOHZ_STATS_KICK BIT(NOHZ_STATS_KICK_BIT) + +#define NOHZ_KICK_MASK (NOHZ_BALANCE_KICK | NOHZ_STATS_KICK) #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags) |