diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/jump_label.c | 4 | ||||
| -rw-r--r-- | kernel/ksysfs.c | 7 | ||||
| -rw-r--r-- | kernel/locking/qspinlock_paravirt.h | 2 | ||||
| -rw-r--r-- | kernel/profile.c | 242 | ||||
| -rw-r--r-- | kernel/sched/core.c | 68 | ||||
| -rw-r--r-- | kernel/sched/cputime.c | 6 | ||||
| -rw-r--r-- | kernel/sched/stats.c | 10 | ||||
| -rw-r--r-- | kernel/task_work.c | 6 | ||||
| -rw-r--r-- | kernel/time/clocksource.c | 2 | ||||
| -rw-r--r-- | kernel/time/tick-broadcast.c | 3 |
10 files changed, 79 insertions, 271 deletions
diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 4ad5ed8adf96..6dc76b590703 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -236,7 +236,7 @@ void static_key_disable_cpuslocked(struct static_key *key) } jump_label_lock(); - if (atomic_cmpxchg(&key->enabled, 1, 0)) + if (atomic_cmpxchg(&key->enabled, 1, 0) == 1) jump_label_update(key); jump_label_unlock(); } @@ -289,7 +289,7 @@ static void __static_key_slow_dec_cpuslocked(struct static_key *key) return; guard(mutex)(&jump_label_mutex); - if (atomic_cmpxchg(&key->enabled, 1, 0)) + if (atomic_cmpxchg(&key->enabled, 1, 0) == 1) jump_label_update(key); else WARN_ON_ONCE(!static_key_slow_try_dec(key)); diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c index 07fb5987b42b..1bab21b4718f 100644 --- a/kernel/ksysfs.c +++ b/kernel/ksysfs.c @@ -92,7 +92,14 @@ static ssize_t profiling_store(struct kobject *kobj, const char *buf, size_t count) { int ret; + static DEFINE_MUTEX(lock); + /* + * We need serialization, for profile_setup() initializes prof_on + * value and profile_init() must not reallocate prof_buffer after + * once allocated. + */ + guard(mutex)(&lock); if (prof_on) return -EEXIST; /* diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h index f5a36e67b593..ac2e22502741 100644 --- a/kernel/locking/qspinlock_paravirt.h +++ b/kernel/locking/qspinlock_paravirt.h @@ -357,7 +357,7 @@ static void pv_wait_node(struct mcs_spinlock *node, struct mcs_spinlock *prev) static void pv_kick_node(struct qspinlock *lock, struct mcs_spinlock *node) { struct pv_node *pn = (struct pv_node *)node; - enum vcpu_state old = vcpu_halted; + u8 old = vcpu_halted; /* * If the vCPU is indeed halted, advance its state to match that of * pv_wait_node(). If OTOH this fails, the vCPU was running and will diff --git a/kernel/profile.c b/kernel/profile.c index 2b775cc5c28f..1fcf1adcf4eb 100644 --- a/kernel/profile.c +++ b/kernel/profile.c @@ -47,30 +47,14 @@ static unsigned short int prof_shift; int prof_on __read_mostly; EXPORT_SYMBOL_GPL(prof_on); -static cpumask_var_t prof_cpu_mask; -#if defined(CONFIG_SMP) && defined(CONFIG_PROC_FS) -static DEFINE_PER_CPU(struct profile_hit *[2], cpu_profile_hits); -static DEFINE_PER_CPU(int, cpu_profile_flip); -static DEFINE_MUTEX(profile_flip_mutex); -#endif /* CONFIG_SMP */ - int profile_setup(char *str) { static const char schedstr[] = "schedule"; - static const char sleepstr[] = "sleep"; static const char kvmstr[] = "kvm"; const char *select = NULL; int par; - if (!strncmp(str, sleepstr, strlen(sleepstr))) { -#ifdef CONFIG_SCHEDSTATS - force_schedstat_enabled(); - prof_on = SLEEP_PROFILING; - select = sleepstr; -#else - pr_warn("kernel sleep profiling requires CONFIG_SCHEDSTATS\n"); -#endif /* CONFIG_SCHEDSTATS */ - } else if (!strncmp(str, schedstr, strlen(schedstr))) { + if (!strncmp(str, schedstr, strlen(schedstr))) { prof_on = SCHED_PROFILING; select = schedstr; } else if (!strncmp(str, kvmstr, strlen(kvmstr))) { @@ -114,11 +98,6 @@ int __ref profile_init(void) buffer_bytes = prof_len*sizeof(atomic_t); - if (!alloc_cpumask_var(&prof_cpu_mask, GFP_KERNEL)) - return -ENOMEM; - - cpumask_copy(prof_cpu_mask, cpu_possible_mask); - prof_buffer = kzalloc(buffer_bytes, GFP_KERNEL|__GFP_NOWARN); if (prof_buffer) return 0; @@ -132,195 +111,16 @@ int __ref profile_init(void) if (prof_buffer) return 0; - free_cpumask_var(prof_cpu_mask); return -ENOMEM; } -#if defined(CONFIG_SMP) && defined(CONFIG_PROC_FS) -/* - * Each cpu has a pair of open-addressed hashtables for pending - * profile hits. read_profile() IPI's all cpus to request them - * to flip buffers and flushes their contents to prof_buffer itself. - * Flip requests are serialized by the profile_flip_mutex. The sole - * use of having a second hashtable is for avoiding cacheline - * contention that would otherwise happen during flushes of pending - * profile hits required for the accuracy of reported profile hits - * and so resurrect the interrupt livelock issue. - * - * The open-addressed hashtables are indexed by profile buffer slot - * and hold the number of pending hits to that profile buffer slot on - * a cpu in an entry. When the hashtable overflows, all pending hits - * are accounted to their corresponding profile buffer slots with - * atomic_add() and the hashtable emptied. As numerous pending hits - * may be accounted to a profile buffer slot in a hashtable entry, - * this amortizes a number of atomic profile buffer increments likely - * to be far larger than the number of entries in the hashtable, - * particularly given that the number of distinct profile buffer - * positions to which hits are accounted during short intervals (e.g. - * several seconds) is usually very small. Exclusion from buffer - * flipping is provided by interrupt disablement (note that for - * SCHED_PROFILING or SLEEP_PROFILING profile_hit() may be called from - * process context). - * The hash function is meant to be lightweight as opposed to strong, - * and was vaguely inspired by ppc64 firmware-supported inverted - * pagetable hash functions, but uses a full hashtable full of finite - * collision chains, not just pairs of them. - * - * -- nyc - */ -static void __profile_flip_buffers(void *unused) -{ - int cpu = smp_processor_id(); - - per_cpu(cpu_profile_flip, cpu) = !per_cpu(cpu_profile_flip, cpu); -} - -static void profile_flip_buffers(void) -{ - int i, j, cpu; - - mutex_lock(&profile_flip_mutex); - j = per_cpu(cpu_profile_flip, get_cpu()); - put_cpu(); - on_each_cpu(__profile_flip_buffers, NULL, 1); - for_each_online_cpu(cpu) { - struct profile_hit *hits = per_cpu(cpu_profile_hits, cpu)[j]; - for (i = 0; i < NR_PROFILE_HIT; ++i) { - if (!hits[i].hits) { - if (hits[i].pc) - hits[i].pc = 0; - continue; - } - atomic_add(hits[i].hits, &prof_buffer[hits[i].pc]); - hits[i].hits = hits[i].pc = 0; - } - } - mutex_unlock(&profile_flip_mutex); -} - -static void profile_discard_flip_buffers(void) -{ - int i, cpu; - - mutex_lock(&profile_flip_mutex); - i = per_cpu(cpu_profile_flip, get_cpu()); - put_cpu(); - on_each_cpu(__profile_flip_buffers, NULL, 1); - for_each_online_cpu(cpu) { - struct profile_hit *hits = per_cpu(cpu_profile_hits, cpu)[i]; - memset(hits, 0, NR_PROFILE_HIT*sizeof(struct profile_hit)); - } - mutex_unlock(&profile_flip_mutex); -} - -static void do_profile_hits(int type, void *__pc, unsigned int nr_hits) -{ - unsigned long primary, secondary, flags, pc = (unsigned long)__pc; - int i, j, cpu; - struct profile_hit *hits; - - pc = min((pc - (unsigned long)_stext) >> prof_shift, prof_len - 1); - i = primary = (pc & (NR_PROFILE_GRP - 1)) << PROFILE_GRPSHIFT; - secondary = (~(pc << 1) & (NR_PROFILE_GRP - 1)) << PROFILE_GRPSHIFT; - cpu = get_cpu(); - hits = per_cpu(cpu_profile_hits, cpu)[per_cpu(cpu_profile_flip, cpu)]; - if (!hits) { - put_cpu(); - return; - } - /* - * We buffer the global profiler buffer into a per-CPU - * queue and thus reduce the number of global (and possibly - * NUMA-alien) accesses. The write-queue is self-coalescing: - */ - local_irq_save(flags); - do { - for (j = 0; j < PROFILE_GRPSZ; ++j) { - if (hits[i + j].pc == pc) { - hits[i + j].hits += nr_hits; - goto out; - } else if (!hits[i + j].hits) { - hits[i + j].pc = pc; - hits[i + j].hits = nr_hits; - goto out; - } - } - i = (i + secondary) & (NR_PROFILE_HIT - 1); - } while (i != primary); - - /* - * Add the current hit(s) and flush the write-queue out - * to the global buffer: - */ - atomic_add(nr_hits, &prof_buffer[pc]); - for (i = 0; i < NR_PROFILE_HIT; ++i) { - atomic_add(hits[i].hits, &prof_buffer[hits[i].pc]); - hits[i].pc = hits[i].hits = 0; - } -out: - local_irq_restore(flags); - put_cpu(); -} - -static int profile_dead_cpu(unsigned int cpu) -{ - struct page *page; - int i; - - if (cpumask_available(prof_cpu_mask)) - cpumask_clear_cpu(cpu, prof_cpu_mask); - - for (i = 0; i < 2; i++) { - if (per_cpu(cpu_profile_hits, cpu)[i]) { - page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[i]); - per_cpu(cpu_profile_hits, cpu)[i] = NULL; - __free_page(page); - } - } - return 0; -} - -static int profile_prepare_cpu(unsigned int cpu) -{ - int i, node = cpu_to_mem(cpu); - struct page *page; - - per_cpu(cpu_profile_flip, cpu) = 0; - - for (i = 0; i < 2; i++) { - if (per_cpu(cpu_profile_hits, cpu)[i]) - continue; - - page = __alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO, 0); - if (!page) { - profile_dead_cpu(cpu); - return -ENOMEM; - } - per_cpu(cpu_profile_hits, cpu)[i] = page_address(page); - - } - return 0; -} - -static int profile_online_cpu(unsigned int cpu) -{ - if (cpumask_available(prof_cpu_mask)) - cpumask_set_cpu(cpu, prof_cpu_mask); - - return 0; -} - -#else /* !CONFIG_SMP */ -#define profile_flip_buffers() do { } while (0) -#define profile_discard_flip_buffers() do { } while (0) - static void do_profile_hits(int type, void *__pc, unsigned int nr_hits) { unsigned long pc; pc = ((unsigned long)__pc - (unsigned long)_stext) >> prof_shift; - atomic_add(nr_hits, &prof_buffer[min(pc, prof_len - 1)]); + if (pc < prof_len) + atomic_add(nr_hits, &prof_buffer[pc]); } -#endif /* !CONFIG_SMP */ void profile_hits(int type, void *__pc, unsigned int nr_hits) { @@ -334,8 +134,8 @@ void profile_tick(int type) { struct pt_regs *regs = get_irq_regs(); - if (!user_mode(regs) && cpumask_available(prof_cpu_mask) && - cpumask_test_cpu(smp_processor_id(), prof_cpu_mask)) + /* This is the old kernel-only legacy profiling */ + if (!user_mode(regs)) profile_hit(type, (void *)profile_pc(regs)); } @@ -358,7 +158,6 @@ read_profile(struct file *file, char __user *buf, size_t count, loff_t *ppos) char *pnt; unsigned long sample_step = 1UL << prof_shift; - profile_flip_buffers(); if (p >= (prof_len+1)*sizeof(unsigned int)) return 0; if (count > (prof_len+1)*sizeof(unsigned int) - p) @@ -404,7 +203,6 @@ static ssize_t write_profile(struct file *file, const char __user *buf, return -EINVAL; } #endif - profile_discard_flip_buffers(); memset(prof_buffer, 0, prof_len * sizeof(atomic_t)); return count; } @@ -418,40 +216,14 @@ static const struct proc_ops profile_proc_ops = { int __ref create_proc_profile(void) { struct proc_dir_entry *entry; -#ifdef CONFIG_SMP - enum cpuhp_state online_state; -#endif - int err = 0; if (!prof_on) return 0; -#ifdef CONFIG_SMP - err = cpuhp_setup_state(CPUHP_PROFILE_PREPARE, "PROFILE_PREPARE", - profile_prepare_cpu, profile_dead_cpu); - if (err) - return err; - - err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "AP_PROFILE_ONLINE", - profile_online_cpu, NULL); - if (err < 0) - goto err_state_prep; - online_state = err; - err = 0; -#endif entry = proc_create("profile", S_IWUSR | S_IRUGO, NULL, &profile_proc_ops); - if (!entry) - goto err_state_onl; - proc_set_size(entry, (1 + prof_len) * sizeof(atomic_t)); - - return err; -err_state_onl: -#ifdef CONFIG_SMP - cpuhp_remove_state(online_state); -err_state_prep: - cpuhp_remove_state(CPUHP_PROFILE_PREPARE); -#endif + if (entry) + proc_set_size(entry, (1 + prof_len) * sizeof(atomic_t)); return err; } subsys_initcall(create_proc_profile); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index a9f655025607..f3951e4a55e5 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7845,6 +7845,30 @@ void set_rq_offline(struct rq *rq) } } +static inline void sched_set_rq_online(struct rq *rq, int cpu) +{ + struct rq_flags rf; + + rq_lock_irqsave(rq, &rf); + if (rq->rd) { + BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); + set_rq_online(rq); + } + rq_unlock_irqrestore(rq, &rf); +} + +static inline void sched_set_rq_offline(struct rq *rq, int cpu) +{ + struct rq_flags rf; + + rq_lock_irqsave(rq, &rf); + if (rq->rd) { + BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); + set_rq_offline(rq); + } + rq_unlock_irqrestore(rq, &rf); +} + /* * used to mark begin/end of suspend/resume: */ @@ -7895,10 +7919,25 @@ static int cpuset_cpu_inactive(unsigned int cpu) return 0; } +static inline void sched_smt_present_inc(int cpu) +{ +#ifdef CONFIG_SCHED_SMT + if (cpumask_weight(cpu_smt_mask(cpu)) == 2) + static_branch_inc_cpuslocked(&sched_smt_present); +#endif +} + +static inline void sched_smt_present_dec(int cpu) +{ +#ifdef CONFIG_SCHED_SMT + if (cpumask_weight(cpu_smt_mask(cpu)) == 2) + static_branch_dec_cpuslocked(&sched_smt_present); +#endif +} + int sched_cpu_activate(unsigned int cpu) { struct rq *rq = cpu_rq(cpu); - struct rq_flags rf; /* * Clear the balance_push callback and prepare to schedule @@ -7906,13 +7945,10 @@ int sched_cpu_activate(unsigned int cpu) */ balance_push_set(cpu, false); -#ifdef CONFIG_SCHED_SMT /* * When going up, increment the number of cores with SMT present. */ - if (cpumask_weight(cpu_smt_mask(cpu)) == 2) - static_branch_inc_cpuslocked(&sched_smt_present); -#endif + sched_smt_present_inc(cpu); set_cpu_active(cpu, true); if (sched_smp_initialized) { @@ -7930,12 +7966,7 @@ int sched_cpu_activate(unsigned int cpu) * 2) At runtime, if cpuset_cpu_active() fails to rebuild the * domains. */ - rq_lock_irqsave(rq, &rf); - if (rq->rd) { - BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); - set_rq_online(rq); - } - rq_unlock_irqrestore(rq, &rf); + sched_set_rq_online(rq, cpu); return 0; } @@ -7943,7 +7974,6 @@ int sched_cpu_activate(unsigned int cpu) int sched_cpu_deactivate(unsigned int cpu) { struct rq *rq = cpu_rq(cpu); - struct rq_flags rf; int ret; /* @@ -7974,20 +8004,14 @@ int sched_cpu_deactivate(unsigned int cpu) */ synchronize_rcu(); - rq_lock_irqsave(rq, &rf); - if (rq->rd) { - BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); - set_rq_offline(rq); - } - rq_unlock_irqrestore(rq, &rf); + sched_set_rq_offline(rq, cpu); -#ifdef CONFIG_SCHED_SMT /* * When going down, decrement the number of cores with SMT present. */ - if (cpumask_weight(cpu_smt_mask(cpu)) == 2) - static_branch_dec_cpuslocked(&sched_smt_present); + sched_smt_present_dec(cpu); +#ifdef CONFIG_SCHED_SMT sched_core_cpu_deactivate(cpu); #endif @@ -7997,6 +8021,8 @@ int sched_cpu_deactivate(unsigned int cpu) sched_update_numa(cpu, false); ret = cpuset_cpu_inactive(cpu); if (ret) { + sched_smt_present_inc(cpu); + sched_set_rq_online(rq, cpu); balance_push_set(cpu, false); set_cpu_active(cpu, true); sched_update_numa(cpu, true); diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c index a5e00293ae43..0bed0fa1acd9 100644 --- a/kernel/sched/cputime.c +++ b/kernel/sched/cputime.c @@ -582,6 +582,12 @@ void cputime_adjust(struct task_cputime *curr, struct prev_cputime *prev, } stime = mul_u64_u64_div_u64(stime, rtime, stime + utime); + /* + * Because mul_u64_u64_div_u64() can approximate on some + * achitectures; enforce the constraint that: a*b/(b+c) <= a. + */ + if (unlikely(stime > rtime)) + stime = rtime; update: /* diff --git a/kernel/sched/stats.c b/kernel/sched/stats.c index 78e48f5426ee..eb0cdcd4d921 100644 --- a/kernel/sched/stats.c +++ b/kernel/sched/stats.c @@ -92,16 +92,6 @@ void __update_stats_enqueue_sleeper(struct rq *rq, struct task_struct *p, trace_sched_stat_blocked(p, delta); - /* - * Blocking time is in units of nanosecs, so shift by - * 20 to get a milliseconds-range estimation of the - * amount of time that the task spent sleeping: - */ - if (unlikely(prof_on == SLEEP_PROFILING)) { - profile_hits(SLEEP_PROFILING, - (void *)get_wchan(p), - delta >> 20); - } account_scheduler_latency(p, delta >> 10, 0); } } diff --git a/kernel/task_work.c b/kernel/task_work.c index 5c2daa7ad3f9..5d14d639ac71 100644 --- a/kernel/task_work.c +++ b/kernel/task_work.c @@ -6,12 +6,14 @@ static struct callback_head work_exited; /* all we need is ->next == NULL */ +#ifdef CONFIG_IRQ_WORK static void task_work_set_notify_irq(struct irq_work *entry) { test_and_set_tsk_thread_flag(current, TIF_NOTIFY_RESUME); } static DEFINE_PER_CPU(struct irq_work, irq_work_NMI_resume) = IRQ_WORK_INIT_HARD(task_work_set_notify_irq); +#endif /** * task_work_add - ask the @task to execute @work->func() @@ -57,6 +59,8 @@ int task_work_add(struct task_struct *task, struct callback_head *work, if (notify == TWA_NMI_CURRENT) { if (WARN_ON_ONCE(task != current)) return -EINVAL; + if (!IS_ENABLED(CONFIG_IRQ_WORK)) + return -EINVAL; } else { /* record the work call stack in order to print it in KASAN reports */ kasan_record_aux_stack(work); @@ -81,9 +85,11 @@ int task_work_add(struct task_struct *task, struct callback_head *work, case TWA_SIGNAL_NO_IPI: __set_notify_signal(task); break; +#ifdef CONFIG_IRQ_WORK case TWA_NMI_CURRENT: irq_work_queue(this_cpu_ptr(&irq_work_NMI_resume)); break; +#endif default: WARN_ON_ONCE(1); break; diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index d25ba49e313c..d0538a75f4c6 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -246,7 +246,7 @@ static enum wd_read_status cs_watchdog_read(struct clocksource *cs, u64 *csnow, wd_delay = cycles_to_nsec_safe(watchdog, *wdnow, wd_end); if (wd_delay <= WATCHDOG_MAX_SKEW) { - if (nretries > 1 || nretries >= max_retries) { + if (nretries > 1 && nretries >= max_retries) { pr_warn("timekeeping watchdog on CPU%d: %s retried %d times before success\n", smp_processor_id(), watchdog->name, nretries); } diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index b4843099a8da..ed58eebb4e8f 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -1141,7 +1141,6 @@ void tick_broadcast_switch_to_oneshot(void) #ifdef CONFIG_HOTPLUG_CPU void hotplug_cpu__broadcast_tick_pull(int deadcpu) { - struct tick_device *td = this_cpu_ptr(&tick_cpu_device); struct clock_event_device *bc; unsigned long flags; @@ -1167,6 +1166,8 @@ void hotplug_cpu__broadcast_tick_pull(int deadcpu) * device to avoid the starvation. */ if (tick_check_broadcast_expired()) { + struct tick_device *td = this_cpu_ptr(&tick_cpu_device); + cpumask_clear_cpu(smp_processor_id(), tick_broadcast_force_mask); tick_program_event(td->evtdev->next_event, 1); } |