diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-06 14:31:50 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-06 14:31:50 -0700 |
commit | e00d4135751bfe786a9e26b5560b185ce3f9f963 (patch) | |
tree | 6945bd6749aab501000f7084e020aa201971e1ff | |
parent | 90489a72fba9529c85e051067ecb41183b8e982e (diff) | |
parent | 08ae95f4fd3b38b257f5dc7e6507e071c27ba0d5 (diff) |
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
"The main changes in this cycle were:
- Make nohz housekeeping processing more permissive and less
intrusive to isolated CPUs
- Decouple CPU-bound workqueue acconting from the scheduler and move
it into the workqueue code.
- Optimize topology building
- Better handle quota and period overflows
- Add more RCU annotations
- Comment updates, misc cleanups"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits)
nohz_full: Allow the boot CPU to be nohz_full
sched/isolation: Require a present CPU in housekeeping mask
kernel/cpu: Allow non-zero CPU to be primary for suspend / kexec freeze
power/suspend: Add function to disable secondaries for suspend
sched/core: Allow the remote scheduler tick to be started on CPU0
sched/nohz: Run NOHZ idle load balancer on HK_FLAG_MISC CPUs
sched/debug: Fix spelling mistake "logaritmic" -> "logarithmic"
sched/topology: Update init_sched_domains() comment
cgroup/cpuset: Update stale generate_sched_domains() comments
sched/core: Check quota and period overflow at usec to nsec conversion
sched/core: Handle overflow in cpu_shares_write_u64
sched/rt: Check integer overflow at usec to nsec conversion
sched/core: Fix typo in comment
sched/core: Make some functions static
sched/core: Unify p->on_rq updates
sched/core: Remove ttwu_activate()
sched/core, workqueues: Distangle worker accounting from rq lock
sched/fair: Remove unneeded prototype of capacity_of()
sched/topology: Skip duplicate group rewrites in build_sched_groups()
sched/topology: Fix build_sched_groups() comment
...
-rw-r--r-- | arch/powerpc/Kconfig | 4 | ||||
-rw-r--r-- | include/linux/cpu.h | 17 | ||||
-rw-r--r-- | include/linux/rcuwait.h | 2 | ||||
-rw-r--r-- | include/linux/sched/topology.h | 4 | ||||
-rw-r--r-- | kernel/cgroup/cpuset.c | 11 | ||||
-rw-r--r-- | kernel/cpu.c | 10 | ||||
-rw-r--r-- | kernel/kexec_core.c | 4 | ||||
-rw-r--r-- | kernel/power/Kconfig | 9 | ||||
-rw-r--r-- | kernel/power/hibernate.c | 12 | ||||
-rw-r--r-- | kernel/power/suspend.c | 4 | ||||
-rw-r--r-- | kernel/sched/core.c | 127 | ||||
-rw-r--r-- | kernel/sched/cpufreq.c | 2 | ||||
-rw-r--r-- | kernel/sched/debug.c | 2 | ||||
-rw-r--r-- | kernel/sched/fair.c | 25 | ||||
-rw-r--r-- | kernel/sched/isolation.c | 18 | ||||
-rw-r--r-- | kernel/sched/rt.c | 5 | ||||
-rw-r--r-- | kernel/sched/sched.h | 18 | ||||
-rw-r--r-- | kernel/sched/topology.c | 31 | ||||
-rw-r--r-- | kernel/time/tick-common.c | 50 | ||||
-rw-r--r-- | kernel/time/tick-sched.c | 34 | ||||
-rw-r--r-- | kernel/workqueue.c | 54 | ||||
-rw-r--r-- | kernel/workqueue_internal.h | 5 |
22 files changed, 255 insertions, 193 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index fab0bf4259c7..88a4fb3647a2 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -313,6 +313,10 @@ config ARCH_SUSPEND_POSSIBLE (PPC_85xx && !PPC_E500MC) || PPC_86xx || PPC_PSERIES \ || 44x || 40x +config ARCH_SUSPEND_NONZERO_CPU + def_bool y + depends on PPC_POWERNV || PPC_PSERIES + config PPC_DCR_NATIVE bool diff --git a/include/linux/cpu.h b/include/linux/cpu.h index 2d9c6f4b78f5..2d62f01108a0 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -137,9 +137,26 @@ static inline int disable_nonboot_cpus(void) return freeze_secondary_cpus(0); } extern void enable_nonboot_cpus(void); + +static inline int suspend_disable_secondary_cpus(void) +{ + int cpu = 0; + + if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU)) + cpu = -1; + + return freeze_secondary_cpus(cpu); +} +static inline void suspend_enable_secondary_cpus(void) +{ + return enable_nonboot_cpus(); +} + #else /* !CONFIG_PM_SLEEP_SMP */ static inline int disable_nonboot_cpus(void) { return 0; } static inline void enable_nonboot_cpus(void) {} +static inline int suspend_disable_secondary_cpus(void) { return 0; } +static inline void suspend_enable_secondary_cpus(void) { } #endif /* !CONFIG_PM_SLEEP_SMP */ void cpu_startup_entry(enum cpuhp_state state); diff --git a/include/linux/rcuwait.h b/include/linux/rcuwait.h index 90bfa3279a01..563290fc194f 100644 --- a/include/linux/rcuwait.h +++ b/include/linux/rcuwait.h @@ -18,7 +18,7 @@ * awoken. */ struct rcuwait { - struct task_struct *task; + struct task_struct __rcu *task; }; #define __RCUWAIT_INITIALIZER(name) \ diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h index 57c7ed3fe465..cfc0a89a7159 100644 --- a/include/linux/sched/topology.h +++ b/include/linux/sched/topology.h @@ -76,8 +76,8 @@ struct sched_domain_shared { struct sched_domain { /* These fields must be setup */ - struct sched_domain *parent; /* top domain must be null terminated */ - struct sched_domain *child; /* bottom domain must be null terminated */ + struct sched_domain __rcu *parent; /* top domain must be null terminated */ + struct sched_domain __rcu *child; /* bottom domain must be null terminated */ struct sched_group *groups; /* the balancing groups of the domain */ unsigned long min_interval; /* Minimum balance interval ms */ unsigned long max_interval; /* Maximum balance interval ms */ diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index 4834c4214e9c..6a1942ed781c 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -740,11 +740,10 @@ static inline int nr_cpusets(void) * Must be called with cpuset_mutex held. * * The three key local variables below are: - * q - a linked-list queue of cpuset pointers, used to implement a - * top-down scan of all cpusets. This scan loads a pointer - * to each cpuset marked is_sched_load_balance into the - * array 'csa'. For our purposes, rebuilding the schedulers - * sched domains, we can ignore !is_sched_load_balance cpusets. + * cp - cpuset pointer, used (together with pos_css) to perform a + * top-down scan of all cpusets. For our purposes, rebuilding + * the schedulers sched domains, we can ignore !is_sched_load_ + * balance cpusets. * csa - (for CpuSet Array) Array of pointers to all the cpusets * that need to be load balanced, for convenient iterative * access by the subsequent code that finds the best partition, @@ -775,7 +774,7 @@ static inline int nr_cpusets(void) static int generate_sched_domains(cpumask_var_t **domains, struct sched_domain_attr **attributes) { - struct cpuset *cp; /* scans q */ + struct cpuset *cp; /* top-down scan of cpusets */ struct cpuset **csa; /* array of all cpuset ptrs */ int csn; /* how many cpuset ptrs in csa so far */ int i, j, k; /* indices for partition finding loops */ diff --git a/kernel/cpu.c b/kernel/cpu.c index 43e741e88691..1e890f548df8 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -9,6 +9,7 @@ #include <linux/notifier.h> #include <linux/sched/signal.h> #include <linux/sched/hotplug.h> +#include <linux/sched/isolation.h> #include <linux/sched/task.h> #include <linux/sched/smt.h> #include <linux/unistd.h> @@ -1199,8 +1200,15 @@ int freeze_secondary_cpus(int primary) int cpu, error = 0; cpu_maps_update_begin(); - if (!cpu_online(primary)) + if (primary == -1) { primary = cpumask_first(cpu_online_mask); + if (!housekeeping_cpu(primary, HK_FLAG_TIMER)) + primary = housekeeping_any_cpu(HK_FLAG_TIMER); + } else { + if (!cpu_online(primary)) + primary = cpumask_first(cpu_online_mask); + } + /* * We take down all of the non-boot CPUs in one shot to avoid races * with the userspace trying to use the CPU hotplug at the same time diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index d7140447be75..fd5c95ff9251 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -1150,7 +1150,7 @@ int kernel_kexec(void) error = dpm_suspend_end(PMSG_FREEZE); if (error) goto Resume_devices; - error = disable_nonboot_cpus(); + error = suspend_disable_secondary_cpus(); if (error) goto Enable_cpus; local_irq_disable(); @@ -1183,7 +1183,7 @@ int kernel_kexec(void) Enable_irqs: local_irq_enable(); Enable_cpus: - enable_nonboot_cpus(); + suspend_enable_secondary_cpus(); dpm_resume_start(PMSG_RESTORE); Resume_devices: dpm_resume_end(PMSG_RESTORE); diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index f8fe57d1022e..9bbaaab14b36 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig @@ -114,6 +114,15 @@ config PM_SLEEP_SMP depends on PM_SLEEP select HOTPLUG_CPU +config PM_SLEEP_SMP_NONZERO_CPU + def_bool y + depends on PM_SLEEP_SMP + depends on ARCH_SUSPEND_NONZERO_CPU + ---help--- + If an arch can suspend (for suspend, hibernate, kexec, etc) on a + non-zero numbered CPU, it may define ARCH_SUSPEND_NONZERO_CPU. This + will allow nohz_full mask to include CPU0. + config PM_AUTOSLEEP bool "Opportunistic sleep" depends on PM_SLEEP diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index abef759de7c8..cfc7a57049e4 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -281,7 +281,7 @@ static int create_image(int platform_mode) if (error || hibernation_test(TEST_PLATFORM)) goto Platform_finish; - error = disable_nonboot_cpus(); + error = suspend_disable_secondary_cpus(); if (error || hibernation_test(TEST_CPUS)) goto Enable_cpus; @@ -323,7 +323,7 @@ static int create_image(int platform_mode) local_irq_enable(); Enable_cpus: - enable_nonboot_cpus(); + suspend_enable_secondary_cpus(); Platform_finish: platform_finish(platform_mode); @@ -417,7 +417,7 @@ int hibernation_snapshot(int platform_mode) int __weak hibernate_resume_nonboot_cpu_disable(void) { - return disable_nonboot_cpus(); + return suspend_disable_secondary_cpus(); } /** @@ -486,7 +486,7 @@ static int resume_target_kernel(bool platform_mode) local_irq_enable(); Enable_cpus: - enable_nonboot_cpus(); + suspend_enable_secondary_cpus(); Cleanup: platform_restore_cleanup(platform_mode); @@ -564,7 +564,7 @@ int hibernation_platform_enter(void) if (error) goto Platform_finish; - error = disable_nonboot_cpus(); + error = suspend_disable_secondary_cpus(); if (error) goto Enable_cpus; @@ -586,7 +586,7 @@ int hibernation_platform_enter(void) local_irq_enable(); Enable_cpus: - enable_nonboot_cpus(); + suspend_enable_secondary_cpus(); Platform_finish: hibernation_ops->finish(); diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index 0bd595a0b610..59b6def23046 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -428,7 +428,7 @@ static int suspend_enter(suspend_state_t state, bool *wakeup) if (suspend_test(TEST_PLATFORM)) goto Platform_wake; - error = disable_nonboot_cpus(); + error = suspend_disable_secondary_cpus(); if (error || suspend_test(TEST_CPUS)) goto Enable_cpus; @@ -458,7 +458,7 @@ static int suspend_enter(suspend_state_t state, bool *wakeup) BUG_ON(irqs_disabled()); Enable_cpus: - enable_nonboot_cpus(); + suspend_enable_secondary_cpus(); Platform_wake: platform_resume_noirq(state); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index ade3f2287d1f..102dfcf0a29a 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -792,10 +792,14 @@ void activate_task(struct rq *rq, struct task_struct *p, int flags) rq->nr_uninterruptible--; enqueue_task(rq, p, flags); + + p->on_rq = TASK_ON_RQ_QUEUED; } void deactivate_task(struct rq *rq, struct task_struct *p, int flags) { + p->on_rq = (flags & DEQUEUE_SLEEP) ? 0 : TASK_ON_RQ_MIGRATING; + if (task_contributes_to_load(p)) rq->nr_uninterruptible++; @@ -920,7 +924,7 @@ static inline bool is_per_cpu_kthread(struct task_struct *p) } /* - * Per-CPU kthreads are allowed to run on !actie && online CPUs, see + * Per-CPU kthreads are allowed to run on !active && online CPUs, see * __set_cpus_allowed_ptr() and select_fallback_rq(). */ static inline bool is_cpu_allowed(struct task_struct *p, int cpu) @@ -1236,11 +1240,9 @@ static void __migrate_swap_task(struct task_struct *p, int cpu) rq_pin_lock(src_rq, &srf); rq_pin_lock(dst_rq, &drf); - p->on_rq = TASK_ON_RQ_MIGRATING; deactivate_task(src_rq, p, 0); set_task_cpu(p, cpu); activate_task(dst_rq, p, 0); - p->on_rq = TASK_ON_RQ_QUEUED; check_preempt_curr(dst_rq, p, 0); rq_unpin_lock(dst_rq, &drf); @@ -1680,16 +1682,6 @@ ttwu_stat(struct task_struct *p, int cpu, int wake_flags) __schedstat_inc(p->se.statistics.nr_wakeups_sync); } -static inline void ttwu_activate(struct rq *rq, struct task_struct *p, int en_flags) -{ - activate_task(rq, p, en_flags); - p->on_rq = TASK_ON_RQ_QUEUED; - - /* If a worker is waking up, notify the workqueue: */ - if (p->flags & PF_WQ_WORKER) - wq_worker_waking_up(p, cpu_of(rq)); -} - /* * Mark the task runnable and perform wakeup-preemption. */ @@ -1741,7 +1733,7 @@ ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags, en_flags |= ENQUEUE_MIGRATED; #endif - ttwu_activate(rq, p, en_flags); + activate_task(rq, p, en_flags); ttwu_do_wakeup(rq, p, wake_flags, rf); } @@ -2106,56 +2098,6 @@ out: } /** - * try_to_wake_up_local - try to wake up a local task with rq lock held - * @p: the thread to be awakened - * @rf: request-queue flags for pinning - * - * Put @p on the run-queue if it's not already there. The caller must - * ensure that this_rq() is locked, @p is bound to this_rq() and not - * the current task. - */ -static void try_to_wake_up_local(struct task_struct *p, struct rq_flags *rf) -{ - struct rq *rq = task_rq(p); - - if (WARN_ON_ONCE(rq != this_rq()) || - WARN_ON_ONCE(p == current)) - return; - - lockdep_assert_held(&rq->lock); - - if (!raw_spin_trylock(&p->pi_lock)) { - /* - * This is OK, because current is on_cpu, which avoids it being - * picked for load-balance and preemption/IRQs are still - * disabled avoiding further scheduler activity on it and we've - * not yet picked a replacement task. - */ - rq_unlock(rq, rf); - raw_spin_lock(&p->pi_lock); - rq_relock(rq, rf); - } - - if (!(p->state & TASK_NORMAL)) - goto out; - - trace_sched_waking(p); - - if (!task_on_rq_queued(p)) { - if (p->in_iowait) { - delayacct_blkio_end(p); - atomic_dec(&rq->nr_iowait); - } - ttwu_activate(rq, p, ENQUEUE_WAKEUP | ENQUEUE_NOCLOCK); - } - - ttwu_do_wakeup(rq, p, 0, rf); - ttwu_stat(p, smp_processor_id(), 0); -out: - raw_spin_unlock(&p->pi_lock); -} - -/** * wake_up_process - Wake up a specific process * @p: The process to be woken up. * @@ -2466,7 +2408,6 @@ void wake_up_new_task(struct task_struct *p) post_init_entity_util_avg(p); activate_task(rq, p, ENQUEUE_NOCLOCK); - p->on_rq = TASK_ON_RQ_QUEUED; trace_sched_wakeup_new(p); check_preempt_curr(rq, p, WF_FORK); #ifdef CONFIG_SMP @@ -3465,25 +3406,11 @@ static void __sched notrace __schedule(bool preempt) prev->state = TASK_RUNNING; } else { deactivate_task(rq, prev, DEQUEUE_SLEEP | DEQUEUE_NOCLOCK); - prev->on_rq = 0; if (prev->in_iowait) { atomic_inc(&rq->nr_iowait); delayacct_blkio_start(); } - - /* - * If a worker went to sleep, notify and ask workqueue - * whether it wants to wake up a task to maintain - * concurrency. - */ - if (prev->flags & PF_WQ_WORKER) { - struct task_struct *to_wakeup; - - to_wakeup = wq_worker_sleeping(prev); - if (to_wakeup) - try_to_wake_up_local(to_wakeup, &rf); - } } switch_count = &prev->nvcsw; } @@ -3543,6 +3470,20 @@ static inline void sched_submit_work(struct task_struct *tsk) { if (!tsk->state || tsk_is_pi_blocked(tsk)) return; + + /* + * If a worker went to sleep, notify and ask workqueue whether + * it wants to wake up a task to maintain concurrency. + * As this function is called inside the schedule() context, + * we disable preemption to avoid it calling schedule() again + * in the possible wakeup of a kworker. + */ + if (tsk->flags & PF_WQ_WORKER) { + preempt_disable(); + wq_worker_sleeping(tsk); + preempt_enable_no_resched(); + } + /* * If we are going to sleep and we have plugged IO queued, * make sure to submit it to avoid deadlocks. @@ -3551,6 +3492,12 @@ static inline void sched_submit_work(struct task_struct *tsk) blk_schedule_flush_plug(tsk); } +static void sched_update_worker(struct task_struct *tsk) +{ + if (tsk->flags & PF_WQ_WORKER) + wq_worker_running(tsk); +} + asmlinkage __visible void __sched schedule(void) { struct task_struct *tsk = current; @@ -3561,6 +3508,7 @@ asmlinkage __visible void __sched schedule(void) __schedule(false); sched_preempt_enable_no_resched(); } while (need_resched()); + sched_update_worker(tsk); } EXPORT_SYMBOL(schedule); @@ -5917,7 +5865,7 @@ void __init sched_init_smp(void) static int __init migration_init(void) { - sched_rq_cpu_starting(smp_processor_id()); + sched_cpu_starting(smp_processor_id()); return 0; } early_initcall(migration_init); @@ -6558,6 +6506,8 @@ static void cpu_cgroup_attach(struct cgroup_taskset *tset) static int cpu_shares_write_u64(struct cgroup_subsys_state *css, struct cftype *cftype, u64 shareval) { + if (shareval > scale_load_down(ULONG_MAX)) + shareval = MAX_SHARES; return sched_group_set_shares(css_tg(css), scale_load(shareval)); } @@ -6573,7 +6523,7 @@ static u64 cpu_shares_read_u64(struct cgroup_subsys_state *css, static DEFINE_MUTEX(cfs_constraints_mutex); const u64 max_cfs_quota_period = 1 * NSEC_PER_SEC; /* 1s */ -const u64 min_cfs_quota_period = 1 * NSEC_PER_MSEC; /* 1ms */ +static const u64 min_cfs_quota_period = 1 * NSEC_PER_MSEC; /* 1ms */ static int __cfs_schedulable(struct task_group *tg, u64 period, u64 runtime); @@ -6653,20 +6603,22 @@ out_unlock: return ret; } -int tg_set_cfs_quota(struct task_group *tg, long cfs_quota_us) +static int tg_set_cfs_quota(struct task_group *tg, long cfs_quota_us) { u64 quota, period; period = ktime_to_ns(tg->cfs_bandwidth.period); if (cfs_quota_us < 0) quota = RUNTIME_INF; - else + else if ((u64)cfs_quota_us <= U64_MAX / NSEC_PER_USEC) quota = (u64)cfs_quota_us * NSEC_PER_USEC; + else + return -EINVAL; return tg_set_cfs_bandwidth(tg, period, quota); } -long tg_get_cfs_quota(struct task_group *tg) +static long tg_get_cfs_quota(struct task_group *tg) { u64 quota_us; @@ -6679,17 +6631,20 @@ long tg_get_cfs_quota(struct task_group *tg) return quota_us; } -int tg_set_cfs_period(struct task_group *tg, long cfs_period_us) +static int tg_set_cfs_period(struct task_group *tg, long cfs_period_us) { u64 quota, period; + if ((u64)cfs_period_us > U64_MAX / NSEC_PER_USEC) + return -EINVAL; + period = (u64)cfs_period_us * NSEC_PER_USEC; quota = tg->cfs_bandwidth.quota; return tg_set_cfs_bandwidth(tg, period, quota); } -long tg_get_cfs_period(struct task_group *tg) +static long tg_get_cfs_period(struct task_group *tg) { u64 cfs_period_us; diff --git a/kernel/sched/cpufreq.c b/kernel/sched/cpufreq.c index 835671f0f917..b5dcd1d83c7f 100644 --- a/kernel/sched/cpufreq.c +++ b/kernel/sched/cpufreq.c @@ -7,7 +7,7 @@ */ #include "sched.h" -DEFINE_PER_CPU(struct update_util_data *, cpufreq_update_util_data); +DEFINE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data); /** * cpufreq_add_update_util_hook - Populate the CPU's update_util_data pointer. diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index 8039d62ae36e..678bfb9bd87f 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -702,7 +702,7 @@ do { \ static const char *sched_tunable_scaling_names[] = { "none", - "logaritmic", + "logarithmic", "linear" }; diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 35f3ea375084..f35930f5e528 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2597,7 +2597,7 @@ out: /* * Drive the periodic memory faults.. */ -void task_tick_numa(struct rq *rq, struct task_struct *curr) +static void task_tick_numa(struct rq *rq, struct task_struct *curr) { struct callback_head *work = &curr->numa_work; u64 period, now; @@ -3571,7 +3571,7 @@ static inline u64 cfs_rq_last_update_time(struct cfs_rq *cfs_rq) * Synchronize entity load avg of dequeued entity without locking * the previous rq. */ -void sync_entity_load_avg(struct sched_entity *se) +static void sync_entity_load_avg(struct sched_entity *se) { struct cfs_rq *cfs_rq = cfs_rq_of(se); u64 last_update_time; @@ -3584,7 +3584,7 @@ void sync_entity_load_avg(struct sched_entity *se) * Task first catches up with cfs_rq, and then subtract * itself from the cfs_rq (task must be off the queue now). */ -void remove_entity_load_avg(struct sched_entity *se) +static void remove_entity_load_avg(struct sched_entity *se) { struct cfs_rq *cfs_rq = cfs_rq_of(se); unsigned long flags; @@ -5145,7 +5145,6 @@ static inline void hrtick_update(struct rq *rq) #ifdef CONFIG_SMP static inline unsigned long cpu_util(int cpu); -static unsigned long capacity_of(int cpu); static inline bool cpu_overutilized(int cpu) { @@ -7521,7 +7520,6 @@ static void detach_task(struct task_struct *p, struct lb_env *env) { lockdep_assert_held(&env->src_rq->lock); - p->on_rq = TASK_ON_RQ_MIGRATING; deactivate_task(env->src_rq, p, DEQUEUE_NOCLOCK); set_task_cpu(p, env->dst_cpu); } @@ -7657,7 +7655,6 @@ static void attach_task(struct rq *rq, struct task_struct *p) BUG_ON(task_rq(p) != rq); activate_task(rq, p, ENQUEUE_NOCLOCK); - p->on_rq = TASK_ON_RQ_QUEUED; check_preempt_curr(rq, p, 0); } @@ -9551,22 +9548,26 @@ static inline int on_null_domain(struct rq *rq) * - When one of the busy CPUs notice that there may be an idle rebalancing * needed, they will kick the idle load balancer, which then does idle * load balancing for all the idle CPUs. + * - HK_FLAG_MISC CPUs are used for this task, because HK_FLAG_SCHED not set + * anywhere yet. */ static inline int find_new_ilb(void) { - int ilb = cpumask_first(nohz.idle_cpus_mask); + int ilb; - if (ilb < nr_cpu_ids && idle_cpu(ilb)) - return ilb; + for_each_cpu_and(ilb, nohz.idle_cpus_mask, + housekeeping_cpumask(HK_FLAG_MISC)) { + if (idle_cpu(ilb)) + return ilb; + } return nr_cpu_ids; } /* - * Kick a CPU to do the nohz balancing, if it is time for it. We pick the - * nohz_load_balancer CPU (if there is one) otherwise fallback to any idle - * CPU (if there is one). + * Kick a CPU to do the nohz balancing, if it is time for it. We pick any + * idle CPU in the HK_FLAG_MISC housekeeping set (if there is one). */ static void kick_ilb(unsigned int flags) { diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c index b02d148e7672..687302051a27 100644 --- a/kernel/sched/isolation.c +++ b/kernel/sched/isolation.c @@ -65,6 +65,7 @@ void __init housekeeping_init(void) static int __init housekeeping_setup(char *str, enum hk_flags flags) { cpumask_var_t non_housekeeping_mask; + cpumask_var_t tmp; int err; alloc_bootmem_cpumask_var(&non_housekeeping_mask); @@ -75,16 +76,23 @@ static int __init housekeeping_setup(char *str, enum hk_flags flags) return 0; } + alloc_bootmem_cpumask_var(&tmp); if (!housekeeping_flags) { alloc_bootmem_cpumask_var(&housekeeping_mask); cpumask_andnot(housekeeping_mask, cpu_possible_mask, non_housekeeping_mask); - if (cpumask_empty(housekeeping_mask)) + + cpumask_andnot(tmp, cpu_present_mask, non_housekeeping_mask); + if (cpumask_empty(tmp)) { + pr_warn("Housekeeping: must include one present CPU, " + "using boot CPU:%d\n", smp_processor_id()); __cpumask_set_cpu(smp_processor_id(), housekeeping_mask); + __cpumask_clear_cpu(smp_processor_id(), non_housekeeping_mask); + } } else { - cpumask_var_t tmp; - - alloc_bootmem_cpumask_var(&tmp); + cpumask_andnot(tmp, cpu_present_mask, non_housekeeping_mask); + if (cpumask_empty(tmp)) + __cpumask_clear_cpu(smp_processor_id(), non_housekeeping_mask); cpumask_andnot(tmp, cpu_possible_mask, non_housekeeping_mask); if (!cpumask_equal(tmp, housekeeping_mask)) { pr_warn("Housekeeping: nohz_full= must match isolcpus=\n"); @@ -92,8 +100,8 @@ static int __init housekeeping_setup(char *str, enum hk_flags flags) free_bootmem_cpumask_var(non_housekeeping_mask); return 0; } - free_bootmem_cpumask_var(tmp); } + free_bootmem_cpumask_var(tmp); if ((flags & HK_FLAG_TICK) && !(housekeeping_flags & HK_FLAG_TICK)) { if (IS_ENABLED(CONFIG_NO_HZ_FULL)) { diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 90fa23d36565..1e6b909dca36 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -2555,6 +2555,8 @@ int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC; if (rt_runtime_us < 0) rt_runtime = RUNTIME_INF; + else if ((u64)rt_runtime_us > U64_MAX / NSEC_PER_USEC) + return -EINVAL; return tg_set_rt_bandwidth(tg, rt_period, rt_runtime); } @@ -2575,6 +2577,9 @@ int sched_group_set_rt_period(struct task_group *tg, u64 rt_period_us) { u64 rt_runtime, rt_period; + if (rt_period_us > U64_MAX / NSEC_PER_USEC) + return -EINVAL; + rt_period = rt_period_us * NSEC_PER_USEC; rt_runtime = tg->rt_bandwidth.rt_runtime; diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index efa686eeff26..b52ed1ada0be 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -780,7 +780,7 @@ struct root_domain { * NULL-terminated list of performance domains intersecting with the * CPUs of the rd. Protected by RCU. */ - struct perf_domain *pd; + struct perf_domain __rcu *pd; }; extern struct root_domain def_root_domain; @@ -869,8 +869,8 @@ struct rq { atomic_t nr_iowait; #ifdef CONFIG_SMP - struct root_domain *rd; - struct sched_domain *sd; + struct root_domain *rd; + struct sched_domain __rcu *sd; unsigned long cpu_capacity; unsigned long cpu_capacity_orig; @@ -1324,13 +1324,13 @@ static inline struct sched_domain *lowest_flag_domain(int cpu, int flag) return sd; } -DECLARE_PER_CPU(struct sched_domain *, sd_llc); +DECLARE_PER_CPU(struct sched_domain __rcu *, sd_llc); DECLARE_PER_CPU(int, sd_llc_size); DECLARE_PER_CPU(int, sd_llc_id); -DECLARE_PER_CPU(struct sched_domain_shared *, sd_llc_shared); -DECLARE_PER_CPU(struct sched_domain *, sd_numa); -DECLARE_PER_CPU(struct sched_domain *, sd_asym_packing); -DECLARE_PER_CPU(struct sched_domain *, sd_asym_cpucapacity); +DECLARE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared); +DECLARE_PER_CPU(struct sched_domain __rcu *, sd_numa); +DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing); +DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_cpucapacity); extern struct static_key_false sched_asym_cpucapacity; struct sched_group_capacity { @@ -2185,7 +2185,7 @@ static inline u64 irq_time_read(int cpu) #endif /* CONFIG_IRQ_TIME_ACCOUNTING */ #ifdef CONFIG_CPU_FREQ -DECLARE_PER_CPU(struct update_util_data *, cpufreq_update_util_data); +DECLARE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data); /** * cpufreq_update_util - Take a note about CPU utilization changes. diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index ab7f371a3a17..f53f89df837d 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -615,13 +615,13 @@ static void destroy_sched_domains(struct sched_domain *sd) * the cpumask of the domain), this allows us to quickly tell if * two CPUs are in the same cache domain, see cpus_share_cache(). */ -DEFINE_PER_CPU(struct sched_domain *, sd_llc); +DEFINE_PER_CPU(struct sched_domain __rcu *, sd_llc); DEFINE_PER_CPU(int, sd_llc_size); DEFINE_PER_CPU(int, sd_llc_id); -DEFINE_PER_CPU(struct sched_domain_shared *, sd_llc_shared); -DEFINE_PER_CPU(struct sched_domain *, sd_numa); -DEFINE_PER_CPU(struct sched_domain *, sd_asym_packing); -DEFINE_PER_CPU(struct sched_domain *, sd_asym_cpucapacity); +DEFINE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared); +DEFINE_PER_CPU(struct sched_domain __rcu *, sd_numa); +DEFINE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing); +DEFINE_PER_CPU(struct sched_domain __rcu *, sd_asym_cpucapacity); DEFINE_STATIC_KEY_FALSE(sched_asym_cpucapacity); static void update_top_cache_domain(int cpu) @@ -1059,6 +1059,7 @@ static struct sched_group *get_group(int cpu, struct sd_data *sdd) struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu); struct sched_domain *child = sd->child; struct sched_group *sg; + bool already_visited; if (child) cpu = cpumask_first(sched_domain_span(child)); @@ -1066,9 +1067,14 @@ static struct sched_group *get_group(int cpu, struct sd_data *sdd) sg = *per_cpu_ptr(sdd->sg, cpu); sg->sgc = *per_cpu_ptr(sdd->sgc, cpu); - /* For claim_allocations: */ - atomic_inc(&sg->ref); - atomic_inc(&sg->sgc->ref); + /* Increase refcounts for claim_allocations: */ + already_visited = atomic_inc_return(&sg->ref) > 1; + /* sgc visits should follow a similar trend as sg */ + WARN_ON(already_visited != (atomic_inc_return(&sg->sgc->ref) > 1)); + + /* If we have already visited that group, it's already initialized. */ + if (already_visited) + return sg; if (child) { cpumask_copy(sched_group_span(sg), sched_domain_span(child)); @@ -1087,8 +1093,8 @@ static struct sched_group *get_group(int cpu, struct sd_data *sdd) /* * build_sched_groups will build a circular linked list of the groups - * covered by the given span, and will set each group's ->cpumask correctly, - * and ->cpu_capacity to 0. + * covered by the given span, will set each group's ->cpumask correctly, + * and will initialize their ->sgc. * * Assumes the sched_domain tree is fully constructed */ @@ -2075,9 +2081,8 @@ void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms) } /* - * Set up scheduler domains and groups. Callers must hold the hotplug lock. - * For now this just excludes isolated CPUs, but could be used to - * exclude other special cases in the future. + * Set up scheduler domains and groups. For now this just excludes isolated + * CPUs, but could be used to exclude other special cases in the future. */ int sched_init_domains(const struct cpumask *cpu_map) { diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c index df401463a191..e49e8091f9ac 100644 --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -46,6 +46,14 @@ ktime_t tick_period; * procedure also covers cpu hotplug. */ int tick_do_timer_cpu __read_mostly = TICK_DO_TIMER_BOOT; +#ifdef CONFIG_NO_HZ_FULL +/* + * tick_do_timer_boot_cpu indicates the boot CPU temporarily owns + * tick_do_timer_cpu and it should be taken over by an eligible secondary + * when one comes online. + */ +static int tick_do_timer_boot_cpu __read_mostly = -1; +#endif /* * Debugging: see timer_list.c @@ -167,6 +175,26 @@ void tick_setup_periodic(struct clock_event_device *dev, int broadcast) } } +#ifdef CONFIG_NO_HZ_FULL +static void giveup_do_timer(void *info) +{ + int cpu = *(unsigned int *)info; + + WARN_ON(tick_do_timer_cpu != smp_processor_id()); + + tick_do_timer_cpu = cpu; +} + +static void tick_take_do_timer_from_boot(void) +{ + int cpu = smp_processor_id(); + int from = tick_do_timer_boot_cpu; + + if (from >= 0 && from != cpu) + smp_call_function_single(from, giveup_do_timer, &cpu, 1); +} +#endif + /* * Setup the tick device */ @@ -186,12 +214,26 @@ static void tick_setup_device(struct tick_device *td, * this cpu: */ if (tick_do_timer_cpu == TICK_DO_TIMER_BOOT) { - if (!tick_nohz_full_cpu(cpu)) - tick_do_timer_cpu = cpu; - else - tick_do_timer_cpu = TICK_DO_TIMER_NONE; + tick_do_timer_cpu = cpu; + tick_next_period = ktime_get(); tick_period = NSEC_PER_SEC / HZ; +#ifdef CONFIG_NO_HZ_FULL + /* + * The boot CPU may be nohz_full, in which case set + * tick_do_timer_boot_cpu so the first housekeeping + * secondary that comes up will take do_timer from + * us. + */ + if (tick_nohz_full_cpu(cpu)) + tick_do_timer_boot_cpu = cpu; + + } else if (tick_do_timer_boot_cpu != -1 && + !tick_nohz_full_cpu(cpu)) { + tick_take_do_timer_from_boot(); + tick_do_timer_boot_cpu = -1; + WARN_ON(tick_do_timer_cpu != cpu); +#endif } /* diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 6fa52cd6df0b..4aa917acbe1c 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -121,10 +121,16 @@ static void tick_sched_do_timer(struct tick_sched *ts, ktime_t now) * into a long sleep. If two CPUs happen to assign themselves to * this duty, then the jiffies update is still serialized by * jiffies_lock. + * + * If nohz_full is enabled, this should not happen because the + * tick_do_timer_cpu never relinquishes. */ - if (unlikely(tick_do_timer_cpu == TICK_DO_TIMER_NONE) - && !tick_nohz_full_cpu(cpu)) + if (unlikely(tick_do_timer_cpu == TICK_DO_TIMER_NONE)) { +#ifdef CONFIG_NO_HZ_FULL + WARN_ON(tick_nohz_full_running); +#endif tick_do_timer_cpu = cpu; + } #endif /* Check, if the jiffies need an update */ @@ -395,8 +401,8 @@ void __init tick_nohz_full_setup(cpumask_var_t cpumask) static int tick_nohz_cpu_down(unsigned int cpu) { /* - * The boot CPU handles housekeeping duty (unbound timers, - * workqueues, timekeeping, ...) on behalf of full dynticks + * The tick_do_timer_cpu CPU handles housekeeping duty (unbound + * timers, workqueues, timekeeping, ...) on behalf of full dynticks * CPUs. It must remain online when nohz full is enabled. */ if (tick_nohz_full_running && tick_do_timer_cpu == cpu) @@ -423,12 +429,15 @@ void __init tick_nohz_init(void) return; } - cpu = smp_processor_id(); + if (IS_ENABLED(CONFIG_PM_SLEEP_SMP) && + !IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU)) { + cpu = smp_processor_id(); - if (cpumask_test_cpu(cpu, tick_nohz_full_mask)) { - pr_warn("NO_HZ: Clearing %d from nohz_full range for timekeeping\n", - cpu); - cpumask_clear_cpu(cpu, tick_nohz_full_mask); + if (cpumask_test_cpu(cpu, tick_nohz_full_mask)) { + pr_warn("NO_HZ: Clearing %d from nohz_full range " + "for timekeeping\n", cpu); + cpumask_clear_cpu(cpu, tick_nohz_full_mask); + } } for_each_cpu(cpu, tick_nohz_full_mask) @@ -904,8 +913,13 @@ static bool can_stop_idle_tick(int cpu, struct tick_sched *ts) /* * Boot safety: make sure the timekeeping duty has been * assigned before entering dyntick-idle mode, + * tick_do_timer_cpu is TICK_DO_TIMER_BOOT */ - if (tick_do_timer_cpu == TICK_DO_TIMER_NONE) + if (unlikely(tick_do_timer_cpu == TICK_DO_TIMER_BOOT)) + return false; + + /* Should not happen for nohz-full */ + if (WARN_ON_ONCE(tick_do_timer_cpu == TICK_DO_TIMER_NONE)) return false; } diff --git a/kernel/workqueue.c b/kernel/workqueue.c index ddee541ea97a..56180c9286f5 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -841,43 +841,32 @@ static void wake_up_worker(struct worker_pool *pool) } /** - * wq_worker_waking_up - a worker is waking up + * wq_worker_running - a worker is running again * @task: task waking up - * @cpu: CPU @task is waking up to * - * This function is called during try_to_wake_up() when a worker is - * being awoken. - * - * CONTEXT: - * spin_lock_irq(rq->lock) + * This function is called when a worker returns from schedule() */ -void wq_worker_waking_up(struct task_struct *task, int cpu) +void wq_worker_running(struct task_struct *task) { struct worker *worker = kthread_data(task); - if (!(worker->flags & WORKER_NOT_RUNNING)) { - WARN_ON_ONCE(worker->pool->cpu != cpu); + if (!worker->sleeping) + return; + if (!(worker->flags & WORKER_NOT_RUNNING)) atomic_inc(&worker->pool->nr_running); - } + worker->sleeping = 0; } /** * wq_worker_sleeping - a worker is going to sleep * @task: task going to sleep * - * This function is called during schedule() when a busy worker is - * going to sleep. Worker on the same cpu can be woken up by - * returning pointer to its task. - * - * CONTEXT: - * spin_lock_irq(rq->lock) - * - * Return: - * Worker task on @cpu to wake up, %NULL if none. + * This function is called from schedule() when a busy worker is + * going to sleep. */ -struct task_struct *wq_worker_sleeping(struct task_struct *task) +void wq_worker_sleeping(struct task_struct *task) { - struct worker *worker = kthread_data(task), *to_wakeup = NULL; + struct worker *next, *worker = kthread_data(task); struct worker_pool *pool; /* @@ -886,13 +875,15 @@ struct task_struct *wq_worker_sleeping(struct task_struct *task) * checking NOT_RUNNING. */ if (worker->flags & WORKER_NOT_RUNNING) - return NULL; + return; pool = worker->pool; - /* this can only happen on the local cpu */ - if (WARN_ON_ONCE(pool->cpu != raw_smp_processor_id())) - return NULL; + if (WARN_ON_ONCE(worker->sleeping)) + return; + + worker->sleeping = 1; + spin_lock_irq(&pool->lock); /* * The counterpart of the following dec_and_test, implied mb, @@ -906,9 +897,12 @@ struct task_struct *wq_worker_sleeping(struct task_struct *task) * lock is safe. */ if (atomic_dec_and_test(&pool->nr_running) && - !list_empty(&pool->worklist)) - to_wakeup = first_idle_worker(pool); - return to_wakeup ? to_wakeup->task : NULL; + !list_empty(&pool->worklist)) { + next = first_idle_worker(pool); + if (next) + wake_up_process(next->task); + } + spin_unlock_irq(&pool->lock); } /** @@ -4929,7 +4923,7 @@ static void rebind_workers(struct worker_pool *pool) * * WRITE_ONCE() is necessary because @worker->flags may be * tested without holding any lock in - * wq_worker_waking_up(). Without it, NOT_RUNNING test may + * wq_worker_running(). Without it, NOT_RUNNING test may * fail incorrectly leading to premature concurrency * management operations. */ diff --git a/kernel/workqueue_internal.h b/kernel/workqueue_internal.h index cb68b03ca89a..498de0e909a4 100644 --- a/kernel/workqueue_internal.h +++ b/kernel/workqueue_internal.h @@ -44,6 +44,7 @@ struct worker { unsigned long last_active; /* L: last active timestamp */ unsigned int flags; /* X: flags */ int id; /* I: worker id */ + int sleeping; /* None */ /* * Opaque string set with work_set_desc(). Printed out with task @@ -72,8 +73,8 @@ static inline struct worker *current_wq_worker(void) * Scheduler hooks for concurrency managed workqueue. Only to be used from * sched/ and workqueue.c. */ -void wq_worker_waking_up(struct task_struct *task, int cpu); -struct task_struct *wq_worker_sleeping(struct task_struct *task); +void wq_worker_running(struct task_struct *task); +void wq_worker_sleeping(struct task_struct *task); work_func_t wq_worker_last_func(struct task_struct *task); #endif /* _KERNEL_WORKQUEUE_INTERNAL_H */ |