diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/events/core.c | 1 | ||||
| -rw-r--r-- | kernel/sched/core.c | 187 | ||||
| -rw-r--r-- | kernel/sched/fair.c | 29 | ||||
| -rw-r--r-- | kernel/sched/rt.c | 2 | ||||
| -rw-r--r-- | kernel/sched/sched.h | 2 | ||||
| -rw-r--r-- | kernel/sys.c | 60 | ||||
| -rw-r--r-- | kernel/time/tick-sched.c | 190 | ||||
| -rw-r--r-- | kernel/time/timekeeping.c | 2 | ||||
| -rw-r--r-- | kernel/time/timer_list.c | 4 |
9 files changed, 310 insertions, 167 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 5b06cbbf6931..f85c0154b333 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3181,7 +3181,6 @@ static void perf_event_for_each(struct perf_event *event, event = event->group_leader; perf_event_for_each_child(event, func); - func(event); list_for_each_entry(sibling, &event->sibling_list, group_entry) perf_event_for_each_child(sibling, func); mutex_unlock(&ctx->mutex); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index c46958e26121..d5594a4268d4 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5556,15 +5556,20 @@ static cpumask_var_t sched_domains_tmpmask; /* sched_domains_mutex */ #ifdef CONFIG_SCHED_DEBUG -static __read_mostly int sched_domain_debug_enabled; +static __read_mostly int sched_debug_enabled; -static int __init sched_domain_debug_setup(char *str) +static int __init sched_debug_setup(char *str) { - sched_domain_debug_enabled = 1; + sched_debug_enabled = 1; return 0; } -early_param("sched_debug", sched_domain_debug_setup); +early_param("sched_debug", sched_debug_setup); + +static inline bool sched_debug(void) +{ + return sched_debug_enabled; +} static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, struct cpumask *groupmask) @@ -5604,7 +5609,12 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, break; } - if (!group->sgp->power) { + /* + * Even though we initialize ->power to something semi-sane, + * we leave power_orig unset. This allows us to detect if + * domain iteration is still funny without causing /0 traps. + */ + if (!group->sgp->power_orig) { printk(KERN_CONT "\n"); printk(KERN_ERR "ERROR: domain->cpu_power not " "set\n"); @@ -5652,7 +5662,7 @@ static void sched_domain_debug(struct sched_domain *sd, int cpu) { int level = 0; - if (!sched_domain_debug_enabled) + if (!sched_debug_enabled) return; if (!sd) { @@ -5673,6 +5683,10 @@ static void sched_domain_debug(struct sched_domain *sd, int cpu) } #else /* !CONFIG_SCHED_DEBUG */ # define sched_domain_debug(sd, cpu) do { } while (0) +static inline bool sched_debug(void) +{ + return false; +} #endif /* CONFIG_SCHED_DEBUG */ static int sd_degenerate(struct sched_domain *sd) @@ -5994,6 +6008,44 @@ struct sched_domain_topology_level { struct sd_data data; }; +/* + * Build an iteration mask that can exclude certain CPUs from the upwards + * domain traversal. + * + * Asymmetric node setups can result in situations where the domain tree is of + * unequal depth, make sure to skip domains that already cover the entire + * range. + * + * In that case build_sched_domains() will have terminated the iteration early + * and our sibling sd spans will be empty. Domains should always include the + * cpu they're built on, so check that. + * + */ +static void build_group_mask(struct sched_domain *sd, struct sched_group *sg) +{ + const struct cpumask *span = sched_domain_span(sd); + struct sd_data *sdd = sd->private; + struct sched_domain *sibling; + int i; + + for_each_cpu(i, span) { + sibling = *per_cpu_ptr(sdd->sd, i); + if (!cpumask_test_cpu(i, sched_domain_span(sibling))) + continue; + + cpumask_set_cpu(i, sched_group_mask(sg)); + } +} + +/* + * Return the canonical balance cpu for this group, this is the first cpu + * of this group that's also in the iteration mask. + */ +int group_balance_cpu(struct sched_group *sg) +{ + return cpumask_first_and(sched_group_cpus(sg), sched_group_mask(sg)); +} + static int build_overlap_sched_groups(struct sched_domain *sd, int cpu) { @@ -6012,6 +6064,12 @@ build_overlap_sched_groups(struct sched_domain *sd, int cpu) if (cpumask_test_cpu(i, covered)) continue; + child = *per_cpu_ptr(sdd->sd, i); + + /* See the comment near build_group_mask(). */ + if (!cpumask_test_cpu(i, sched_domain_span(child))) + continue; + sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(), GFP_KERNEL, cpu_to_node(cpu)); @@ -6019,8 +6077,6 @@ build_overlap_sched_groups(struct sched_domain *sd, int cpu) goto fail; sg_span = sched_group_cpus(sg); - - child = *per_cpu_ptr(sdd->sd, i); if (child->child) { child = child->child; cpumask_copy(sg_span, sched_domain_span(child)); @@ -6030,13 +6086,24 @@ build_overlap_sched_groups(struct sched_domain *sd, int cpu) cpumask_or(covered, covered, sg_span); sg->sgp = *per_cpu_ptr(sdd->sgp, i); - atomic_inc(&sg->sgp->ref); + if (atomic_inc_return(&sg->sgp->ref) == 1) + build_group_mask(sd, sg); + /* + * Initialize sgp->power such that even if we mess up the + * domains and no possible iteration will get us here, we won't + * die on a /0 trap. + */ + sg->sgp->power = SCHED_POWER_SCALE * cpumask_weight(sg_span); + + /* + * Make sure the first group of this domain contains the + * canonical balance cpu. Otherwise the sched_domain iteration + * breaks. See update_sg_lb_stats(). + */ if ((!groups && cpumask_test_cpu(cpu, sg_span)) || - cpumask_first(sg_span) == cpu) { - WARN_ON_ONCE(!cpumask_test_cpu(cpu, sg_span)); + group_balance_cpu(sg) == cpu) groups = sg; - } if (!first) first = sg; @@ -6109,6 +6176,7 @@ build_sched_groups(struct sched_domain *sd, int cpu) cpumask_clear(sched_group_cpus(sg)); sg->sgp->power = 0; + cpumask_setall(sched_group_mask(sg)); for_each_cpu(j, span) { if (get_group(j, sdd, NULL) != group) @@ -6150,7 +6218,7 @@ static void init_sched_groups_power(int cpu, struct sched_domain *sd) sg = sg->next; } while (sg != sd->groups); - if (cpu != group_first_cpu(sg)) + if (cpu != group_balance_cpu(sg)) return; update_group_power(sd, cpu); @@ -6200,11 +6268,8 @@ int sched_domain_level_max; static int __init setup_relax_domain_level(char *str) { - unsigned long val; - - val = simple_strtoul(str, NULL, 0); - if (val < sched_domain_level_max) - default_relax_domain_level = val; + if (kstrtoint(str, 0, &default_relax_domain_level)) + pr_warn("Unable to set relax_domain_level\n"); return 1; } @@ -6314,14 +6379,13 @@ static struct sched_domain_topology_level *sched_domain_topology = default_topol #ifdef CONFIG_NUMA static int sched_domains_numa_levels; -static int sched_domains_numa_scale; static int *sched_domains_numa_distance; static struct cpumask ***sched_domains_numa_masks; static int sched_domains_curr_level; static inline int sd_local_flags(int level) { - if (sched_domains_numa_distance[level] > REMOTE_DISTANCE) + if (sched_domains_numa_distance[level] > RECLAIM_DISTANCE) return 0; return SD_BALANCE_EXEC | SD_BALANCE_FORK | SD_WAKE_AFFINE; @@ -6379,6 +6443,42 @@ static const struct cpumask *sd_numa_mask(int cpu) return sched_domains_numa_masks[sched_domains_curr_level][cpu_to_node(cpu)]; } +static void sched_numa_warn(const char *str) +{ + static int done = false; + int i,j; + + if (done) + return; + + done = true; + + printk(KERN_WARNING "ERROR: %s\n\n", str); + + for (i = 0; i < nr_node_ids; i++) { + printk(KERN_WARNING " "); + for (j = 0; j < nr_node_ids; j++) + printk(KERN_CONT "%02d ", node_distance(i,j)); + printk(KERN_CONT "\n"); + } + printk(KERN_WARNING "\n"); +} + +static bool find_numa_distance(int distance) +{ + int i; + + if (distance == node_distance(0, 0)) + return true; + + for (i = 0; i < sched_domains_numa_levels; i++) { + if (sched_domains_numa_distance[i] == distance) + return true; + } + + return false; +} + static void sched_init_numa(void) { int next_distance, curr_distance = node_distance(0, 0); @@ -6386,7 +6486,6 @@ static void sched_init_numa(void) int level = 0; int i, j, k; - sched_domains_numa_scale = curr_distance; sched_domains_numa_distance = kzalloc(sizeof(int) * nr_node_ids, GFP_KERNEL); if (!sched_domains_numa_distance) return; @@ -6397,23 +6496,41 @@ static void sched_init_numa(void) * * Assumes node_distance(0,j) includes all distances in * node_distance(i,j) in order to avoid cubic time. - * - * XXX: could be optimized to O(n log n) by using sort() */ next_distance = curr_distance; for (i = 0; i < nr_node_ids; i++) { for (j = 0; j < nr_node_ids; j++) { - int distance = node_distance(0, j); - if (distance > curr_distance && - (distance < next_distance || - next_distance == curr_distance)) - next_distance = distance; + for (k = 0; k < nr_node_ids; k++) { + int distance = node_distance(i, k); + + if (distance > curr_distance && + (distance < next_distance || + next_distance == curr_distance)) + next_distance = distance; + + /* + * While not a strong assumption it would be nice to know + * about cases where if node A is connected to B, B is not + * equally connected to A. + */ + if (sched_debug() && node_distance(k, i) != distance) + sched_numa_warn("Node-distance not symmetric"); + + if (sched_debug() && i && !find_numa_distance(distance)) + sched_numa_warn("Node-0 not representative"); + } + if (next_distance != curr_distance) { + sched_domains_numa_distance[level++] = next_distance; + sched_domains_numa_levels = level; + curr_distance = next_distance; + } else break; } - if (next_distance != curr_distance) { - sched_domains_numa_distance[level++] = next_distance; - sched_domains_numa_levels = level; - curr_distance = next_distance; - } else break; + + /* + * In case of sched_debug() we verify the above assumption. + */ + if (!sched_debug()) + break; } /* * 'level' contains the number of unique distances, excluding the @@ -6525,7 +6642,7 @@ static int __sdt_alloc(const struct cpumask *cpu_map) *per_cpu_ptr(sdd->sg, j) = sg; - sgp = kzalloc_node(sizeof(struct sched_group_power), + sgp = kzalloc_node(sizeof(struct sched_group_power) + cpumask_size(), GFP_KERNEL, cpu_to_node(j)); if (!sgp) return -ENOMEM; @@ -6578,7 +6695,6 @@ struct sched_domain *build_sched_domain(struct sched_domain_topology_level *tl, if (!sd) return child; - set_domain_attribute(sd, attr); cpumask_and(sched_domain_span(sd), cpu_map, tl->mask(cpu)); if (child) { sd->level = child->level + 1; @@ -6586,6 +6702,7 @@ struct sched_domain *build_sched_domain(struct sched_domain_topology_level *tl, child->parent = sd; } sd->child = child; + set_domain_attribute(sd, attr); return sd; } diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index b2a2d236f27b..c099cc6eebe3 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3602,7 +3602,7 @@ void update_group_power(struct sched_domain *sd, int cpu) } while (group != child->groups); } - sdg->sgp->power = power; + sdg->sgp->power_orig = sdg->sgp->power = power; } /* @@ -3632,7 +3632,7 @@ fix_small_capacity(struct sched_domain *sd, struct sched_group *group) /** * update_sg_lb_stats - Update sched_group's statistics for load balancing. - * @sd: The sched_domain whose statistics are to be updated. + * @env: The load balancing environment. * @group: sched_group whose statistics are to be updated. * @load_idx: Load index of sched_domain of this_cpu for load calc. * @local_group: Does group contain this_cpu. @@ -3652,7 +3652,7 @@ static inline void update_sg_lb_stats(struct lb_env *env, int i; if (local_group) - balance_cpu = group_first_cpu(group); + balance_cpu = group_balance_cpu(group); /* Tally up the load of all CPUs in the group */ max_cpu_load = 0; @@ -3667,7 +3667,8 @@ static inline void update_sg_lb_stats(struct lb_env *env, /* Bias balancing toward cpus of our domain */ if (local_group) { - if (idle_cpu(i) && !first_idle_cpu) { + if (idle_cpu(i) && !first_idle_cpu && + cpumask_test_cpu(i, sched_group_mask(group))) { first_idle_cpu = 1; balance_cpu = i; } @@ -3741,11 +3742,10 @@ static inline void update_sg_lb_stats(struct lb_env *env, /** * update_sd_pick_busiest - return 1 on busiest group - * @sd: sched_domain whose statistics are to be checked + * @env: The load balancing environment. * @sds: sched_domain statistics * @sg: sched_group candidate to be checked for being the busiest * @sgs: sched_group statistics - * @this_cpu: the current cpu * * Determine if @sg is a busier group than the previously selected * busiest group. @@ -3783,9 +3783,7 @@ static bool update_sd_pick_busiest(struct lb_env *env, /** * update_sd_lb_stats - Update sched_domain's statistics for load balancing. - * @sd: sched_domain whose statistics are to be updated. - * @this_cpu: Cpu for which load balance is currently performed. - * @idle: Idle status of this_cpu + * @env: The load balancing environment. * @cpus: Set of cpus considered for load balancing. * @balance: Should we balance. * @sds: variable to hold the statistics for this sched_domain. @@ -3874,10 +3872,8 @@ static inline void update_sd_lb_stats(struct lb_env *env, * Returns 1 when packing is required and a task should be moved to * this CPU. The amount of the imbalance is returned in *imbalance. * - * @sd: The sched_domain whose packing is to be checked. + * @env: The load balancing environment. * @sds: Statistics of the sched_domain which is to be packed - * @this_cpu: The cpu at whose sched_domain we're performing load-balance. - * @imbalance: returns amount of imbalanced due to packing. */ static int check_asym_packing(struct lb_env *env, struct sd_lb_stats *sds) { @@ -3903,9 +3899,8 @@ static int check_asym_packing(struct lb_env *env, struct sd_lb_stats *sds) * fix_small_imbalance - Calculate the minor imbalance that exists * amongst the groups of a sched_domain, during * load balancing. + * @env: The load balancing environment. * @sds: Statistics of the sched_domain whose imbalance is to be calculated. - * @this_cpu: The cpu at whose sched_domain we're performing load-balance. - * @imbalance: Variable to store the imbalance. */ static inline void fix_small_imbalance(struct lb_env *env, struct sd_lb_stats *sds) @@ -4048,11 +4043,7 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s * Also calculates the amount of weighted load which should be moved * to restore balance. * - * @sd: The sched_domain whose busiest group is to be returned. - * @this_cpu: The cpu for which load balancing is currently being performed. - * @imbalance: Variable which stores amount of weighted load which should - * be moved to restore balance/put a group to idle. - * @idle: The idle status of this_cpu. + * @env: The load balancing environment. * @cpus: The set of CPUs under consideration for load-balancing. * @balance: Pointer to a variable indicating if this_cpu * is the appropriate cpu to perform load balancing at this_level. diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 2a4e8dffbd6b..573e1ca01102 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -1562,7 +1562,7 @@ static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq) task_running(rq, task) || !task->on_rq)) { - raw_spin_unlock(&lowest_rq->lock); + double_unlock_balance(rq, lowest_rq); lowest_rq = NULL; break; } diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index ba9dccfd24ce..6d52cea7f33d 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -526,6 +526,8 @@ static inline struct sched_domain *highest_flag_domain(int cpu, int flag) DECLARE_PER_CPU(struct sched_domain *, sd_llc); DECLARE_PER_CPU(int, sd_llc_id); +extern int group_balance_cpu(struct sched_group *sg); + #endif /* CONFIG_SMP */ #include "stats.h" diff --git a/kernel/sys.c b/kernel/sys.c index 9ff89cb9657a..f0ec44dcd415 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1786,27 +1786,13 @@ SYSCALL_DEFINE1(umask, int, mask) } #ifdef CONFIG_CHECKPOINT_RESTORE -static bool vma_flags_mismatch(struct vm_area_struct *vma, - unsigned long required, - unsigned long banned) -{ - return (vma->vm_flags & required) != required || - (vma->vm_flags & banned); -} - static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd) { + struct vm_area_struct *vma; struct file *exe_file; struct dentry *dentry; int err; - /* - * Setting new mm::exe_file is only allowed when no VM_EXECUTABLE vma's - * remain. So perform a quick test first. - */ - if (mm->num_exe_file_vmas) - return -EBUSY; - exe_file = fget(fd); if (!exe_file) return -EBADF; @@ -1827,17 +1813,30 @@ static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd) if (err) goto exit; + down_write(&mm->mmap_sem); + + /* + * Forbid mm->exe_file change if there are mapped other files. + */ + err = -EBUSY; + for (vma = mm->mmap; vma; vma = vma->vm_next) { + if (vma->vm_file && !path_equal(&vma->vm_file->f_path, + &exe_file->f_path)) + goto exit_unlock; + } + /* * The symlink can be changed only once, just to disallow arbitrary * transitions malicious software might bring in. This means one * could make a snapshot over all processes running and monitor * /proc/pid/exe changes to notice unusual activity if needed. */ - down_write(&mm->mmap_sem); - if (likely(!mm->exe_file)) - set_mm_exe_file(mm, exe_file); - else - err = -EBUSY; + err = -EPERM; + if (test_and_set_bit(MMF_EXE_FILE_CHANGED, &mm->flags)) + goto exit_unlock; + + set_mm_exe_file(mm, exe_file); +exit_unlock: up_write(&mm->mmap_sem); exit: @@ -1862,7 +1861,7 @@ static int prctl_set_mm(int opt, unsigned long addr, if (opt == PR_SET_MM_EXE_FILE) return prctl_set_mm_exe_file(mm, (unsigned int)addr); - if (addr >= TASK_SIZE) + if (addr >= TASK_SIZE || addr < mmap_min_addr) return -EINVAL; error = -EINVAL; @@ -1924,12 +1923,6 @@ static int prctl_set_mm(int opt, unsigned long addr, error = -EFAULT; goto out; } -#ifdef CONFIG_STACK_GROWSUP - if (vma_flags_mismatch(vma, VM_READ | VM_WRITE | VM_GROWSUP, 0)) -#else - if (vma_flags_mismatch(vma, VM_READ | VM_WRITE | VM_GROWSDOWN, 0)) -#endif - goto out; if (opt == PR_SET_MM_START_STACK) mm->start_stack = addr; else if (opt == PR_SET_MM_ARG_START) @@ -1981,12 +1974,22 @@ out: up_read(&mm->mmap_sem); return error; } + +static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr) +{ + return put_user(me->clear_child_tid, tid_addr); +} + #else /* CONFIG_CHECKPOINT_RESTORE */ static int prctl_set_mm(int opt, unsigned long addr, unsigned long arg4, unsigned long arg5) { return -EINVAL; } +static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr) +{ + return -EINVAL; +} #endif SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, @@ -2124,6 +2127,9 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, else return -EINVAL; break; + case PR_GET_TID_ADDRESS: + error = prctl_get_tid_address(me, (int __user **)arg2); + break; default: return -EINVAL; } diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index da70c6db496c..60c9c60e9108 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -271,49 +271,15 @@ u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time) } EXPORT_SYMBOL_GPL(get_cpu_iowait_time_us); -static void tick_nohz_stop_sched_tick(struct tick_sched *ts) +static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, + ktime_t now, int cpu) { unsigned long seq, last_jiffies, next_jiffies, delta_jiffies; - ktime_t last_update, expires, now; + ktime_t last_update, expires, ret = { .tv64 = 0 }; struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev; u64 time_delta; - int cpu; - - cpu = smp_processor_id(); - ts = &per_cpu(tick_cpu_sched, cpu); - - now = tick_nohz_start_idle(cpu, ts); - - /* - * If this cpu is offline and it is the one which updates - * jiffies, then give up the assignment and let it be taken by - * the cpu which runs the tick timer next. If we don't drop - * this here the jiffies might be stale and do_timer() never - * invoked. - */ - if (unlikely(!cpu_online(cpu))) { - if (cpu == tick_do_timer_cpu) - tick_do_timer_cpu = TICK_DO_TIMER_NONE; - } - - if (unlikely(ts->nohz_mode == NOHZ_MODE_INACTIVE)) - return; - if (need_resched()) - return; - - if (unlikely(local_softirq_pending() && cpu_online(cpu))) { - static int ratelimit; - - if (ratelimit < 10) { - printk(KERN_ERR "NOHZ: local_softirq_pending %02x\n", - (unsigned int) local_softirq_pending()); - ratelimit++; - } - return; - } - ts->idle_calls++; /* Read jiffies and the time when jiffies were updated last */ do { seq = read_seqbegin(&xtime_lock); @@ -392,6 +358,8 @@ static void tick_nohz_stop_sched_tick(struct tick_sched *ts) if (ts->tick_stopped && ktime_equal(expires, dev->next_event)) goto out; + ret = expires; + /* * nohz_stop_sched_tick can be called several times before * the nohz_restart_sched_tick is called. This happens when @@ -402,16 +370,10 @@ static void tick_nohz_stop_sched_tick(struct tick_sched *ts) if (!ts->tick_stopped) { select_nohz_load_balancer(1); - ts->idle_tick = hrtimer_get_expires(&ts->sched_timer); + ts->last_tick = hrtimer_get_expires(&ts->sched_timer); ts->tick_stopped = 1; - ts->idle_jiffies = last_jiffies; } - ts->idle_sleeps++; - - /* Mark expires */ - ts->idle_expires = expires; - /* * If the expiration time == KTIME_MAX, then * in this case we simply stop the tick timer. @@ -442,6 +404,65 @@ out: ts->next_jiffies = next_jiffies; ts->last_jiffies = last_jiffies; ts->sleep_length = ktime_sub(dev->next_event, now); + + return ret; +} + +static bool can_stop_idle_tick(int cpu, struct tick_sched *ts) +{ + /* + * If this cpu is offline and it is the one which updates + * jiffies, then give up the assignment and let it be taken by + * the cpu which runs the tick timer next. If we don't drop + * this here the jiffies might be stale and do_timer() never + * invoked. + */ + if (unlikely(!cpu_online(cpu))) { + if (cpu == tick_do_timer_cpu) + tick_do_timer_cpu = TICK_DO_TIMER_NONE; + } + + if (unlikely(ts->nohz_mode == NOHZ_MODE_INACTIVE)) + return false; + + if (need_resched()) + return false; + + if (unlikely(local_softirq_pending() && cpu_online(cpu))) { + static int ratelimit; + + if (ratelimit < 10) { + printk(KERN_ERR "NOHZ: local_softirq_pending %02x\n", + (unsigned int) local_softirq_pending()); + ratelimit++; + } + return false; + } + + return true; +} + +static void __tick_nohz_idle_enter(struct tick_sched *ts) +{ + ktime_t now, expires; + int cpu = smp_processor_id(); + + now = tick_nohz_start_idle(cpu, ts); + + if (can_stop_idle_tick(cpu, ts)) { + int was_stopped = ts->tick_stopped; + + ts->idle_calls++; + + expires = tick_nohz_stop_sched_tick(ts, now, cpu); + if (expires.tv64 > 0LL) { + ts->idle_sleeps++; + ts->idle_expires = expires; + } + + if (!was_stopped && ts->tick_stopped) + ts->idle_jiffies = ts->last_jiffies; + } } /** @@ -479,7 +500,7 @@ void tick_nohz_idle_enter(void) * update of the idle time accounting in tick_nohz_start_idle(). */ ts->inidle = 1; - tick_nohz_stop_sched_tick(ts); + __tick_nohz_idle_enter(ts); local_irq_enable(); } @@ -499,7 +520,7 @@ void tick_nohz_irq_exit(void) if (!ts->inidle) return; - tick_nohz_stop_sched_tick(ts); + __tick_nohz_idle_enter(ts); } /** @@ -517,7 +538,7 @@ ktime_t tick_nohz_get_sleep_length(void) static void tick_nohz_restart(struct tick_sched *ts, ktime_t now) { hrtimer_cancel(&ts->sched_timer); - hrtimer_set_expires(&ts->sched_timer, ts->idle_tick); + hrtimer_set_expires(&ts->sched_timer, ts->last_tick); while (1) { /* Forward the time to expire in the future */ @@ -540,6 +561,41 @@ static void tick_nohz_restart(struct tick_sched *ts, ktime_t now) } } +static void tick_nohz_restart_sched_tick(struct tick_sched *ts, ktime_t now) +{ + /* Update jiffies first */ + select_nohz_load_balancer(0); + tick_do_update_jiffies64(now); + update_cpu_load_nohz(); + + touch_softlockup_watchdog(); + /* + * Cancel the scheduled timer and restore the tick + */ + ts->tick_stopped = 0; + ts->idle_exittime = now; + + tick_nohz_restart(ts, now); +} + +static void tick_nohz_account_idle_ticks(struct tick_sched *ts) +{ +#ifndef CONFIG_VIRT_CPU_ACCOUNTING + unsigned long ticks; + /* + * We stopped the tick in idle. Update process times would miss the + * time we slept as update_process_times does only a 1 tick + * accounting. Enforce that this is accounted to idle ! + */ + ticks = jiffies - ts->idle_jiffies; + /* + * We might be one off. Do not randomly account a huge number of ticks! + */ + if (ticks && ticks < LONG_MAX) + account_idle_ticks(ticks); +#endif +} + /** * tick_nohz_idle_exit - restart the idle tick from the idle task * @@ -551,9 +607,6 @@ void tick_nohz_idle_exit(void) { int cpu = smp_processor_id(); struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); -#ifndef CONFIG_VIRT_CPU_ACCOUNTING - unsigned long ticks; -#endif ktime_t now; local_irq_disable(); @@ -568,39 +621,11 @@ void tick_nohz_idle_exit(void) if (ts->idle_active) tick_nohz_stop_idle(cpu, now); - if (!ts->tick_stopped) { - local_irq_enable(); - return; + if (ts->tick_stopped) { + tick_nohz_restart_sched_tick(ts, now); + tick_nohz_account_idle_ticks(ts); } - /* Update jiffies first */ - select_nohz_load_balancer(0); - tick_do_update_jiffies64(now); - update_cpu_load_nohz(); - -#ifndef CONFIG_VIRT_CPU_ACCOUNTING - /* - * We stopped the tick in idle. Update process times would miss the - * time we slept as update_process_times does only a 1 tick - * accounting. Enforce that this is accounted to idle ! - */ - ticks = jiffies - ts->idle_jiffies; - /* - * We might be one off. Do not randomly account a huge number of ticks! - */ - if (ticks && ticks < LONG_MAX) - account_idle_ticks(ticks); -#endif - - touch_softlockup_watchdog(); - /* - * Cancel the scheduled timer and restore the tick - */ - ts->tick_stopped = 0; - ts->idle_exittime = now; - - tick_nohz_restart(ts, now); - local_irq_enable(); } @@ -804,7 +829,8 @@ static enum hrtimer_restart tick_sched_timer(struct hrtimer *timer) */ if (ts->tick_stopped) { touch_softlockup_watchdog(); - ts->idle_jiffies++; + if (idle_cpu(cpu)) + ts->idle_jiffies++; } update_process_times(user_mode(regs)); profile_tick(CPU_PROFILING); diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 6e46cacf5969..6f46a00a1e8a 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -962,6 +962,7 @@ static cycle_t logarithmic_accumulation(cycle_t offset, int shift) timekeeper.xtime.tv_sec++; leap = second_overflow(timekeeper.xtime.tv_sec); timekeeper.xtime.tv_sec += leap; + timekeeper.wall_to_monotonic.tv_sec -= leap; } /* Accumulate raw time */ @@ -1077,6 +1078,7 @@ static void update_wall_time(void) timekeeper.xtime.tv_sec++; leap = second_overflow(timekeeper.xtime.tv_sec); timekeeper.xtime.tv_sec += leap; + timekeeper.wall_to_monotonic.tv_sec -= leap; } timekeeping_update(false); diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c index 3258455549f4..af5a7e9f164b 100644 --- a/kernel/time/timer_list.c +++ b/kernel/time/timer_list.c @@ -167,7 +167,7 @@ static void print_cpu(struct seq_file *m, int cpu, u64 now) { struct tick_sched *ts = tick_get_tick_sched(cpu); P(nohz_mode); - P_ns(idle_tick); + P_ns(last_tick); P(tick_stopped); P(idle_jiffies); P(idle_calls); @@ -259,7 +259,7 @@ static int timer_list_show(struct seq_file *m, void *v) u64 now = ktime_to_ns(ktime_get()); int cpu; - SEQ_printf(m, "Timer List Version: v0.6\n"); + SEQ_printf(m, "Timer List Version: v0.7\n"); SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES); SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now); |
