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authorLinus Torvalds <torvalds@linux-foundation.org>2014-06-08 11:31:16 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-06-08 11:31:16 -0700
commit3f17ea6dea8ba5668873afa54628a91aaa3fb1c0 (patch)
treeafbeb2accd4c2199ddd705ae943995b143a0af02 /kernel/sched/core.c
parent1860e379875dfe7271c649058aeddffe5afd9d0d (diff)
parent1a5700bc2d10cd379a795fd2bb377a190af5acd4 (diff)
Merge branch 'next' (accumulated 3.16 merge window patches) into master
Now that 3.15 is released, this merges the 'next' branch into 'master', bringing us to the normal situation where my 'master' branch is the merge window. * accumulated work in next: (6809 commits) ufs: sb mutex merge + mutex_destroy powerpc: update comments for generic idle conversion cris: update comments for generic idle conversion idle: remove cpu_idle() forward declarations nbd: zero from and len fields in NBD_CMD_DISCONNECT. mm: convert some level-less printks to pr_* MAINTAINERS: adi-buildroot-devel is moderated MAINTAINERS: add linux-api for review of API/ABI changes mm/kmemleak-test.c: use pr_fmt for logging fs/dlm/debug_fs.c: replace seq_printf by seq_puts fs/dlm/lockspace.c: convert simple_str to kstr fs/dlm/config.c: convert simple_str to kstr mm: mark remap_file_pages() syscall as deprecated mm: memcontrol: remove unnecessary memcg argument from soft limit functions mm: memcontrol: clean up memcg zoneinfo lookup mm/memblock.c: call kmemleak directly from memblock_(alloc|free) mm/mempool.c: update the kmemleak stack trace for mempool allocations lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations mm: introduce kmemleak_update_trace() mm/kmemleak.c: use %u to print ->checksum ...
Diffstat (limited to 'kernel/sched/core.c')
-rw-r--r--kernel/sched/core.c349
1 files changed, 199 insertions, 150 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 084d17f89139..48e78b657d23 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -90,6 +90,22 @@
#define CREATE_TRACE_POINTS
#include <trace/events/sched.h>
+#ifdef smp_mb__before_atomic
+void __smp_mb__before_atomic(void)
+{
+ smp_mb__before_atomic();
+}
+EXPORT_SYMBOL(__smp_mb__before_atomic);
+#endif
+
+#ifdef smp_mb__after_atomic
+void __smp_mb__after_atomic(void)
+{
+ smp_mb__after_atomic();
+}
+EXPORT_SYMBOL(__smp_mb__after_atomic);
+#endif
+
void start_bandwidth_timer(struct hrtimer *period_timer, ktime_t period)
{
unsigned long delta;
@@ -506,6 +522,39 @@ static inline void init_hrtick(void)
#endif /* CONFIG_SCHED_HRTICK */
/*
+ * cmpxchg based fetch_or, macro so it works for different integer types
+ */
+#define fetch_or(ptr, val) \
+({ typeof(*(ptr)) __old, __val = *(ptr); \
+ for (;;) { \
+ __old = cmpxchg((ptr), __val, __val | (val)); \
+ if (__old == __val) \
+ break; \
+ __val = __old; \
+ } \
+ __old; \
+})
+
+#ifdef TIF_POLLING_NRFLAG
+/*
+ * Atomically set TIF_NEED_RESCHED and test for TIF_POLLING_NRFLAG,
+ * this avoids any races wrt polling state changes and thereby avoids
+ * spurious IPIs.
+ */
+static bool set_nr_and_not_polling(struct task_struct *p)
+{
+ struct thread_info *ti = task_thread_info(p);
+ return !(fetch_or(&ti->flags, _TIF_NEED_RESCHED) & _TIF_POLLING_NRFLAG);
+}
+#else
+static bool set_nr_and_not_polling(struct task_struct *p)
+{
+ set_tsk_need_resched(p);
+ return true;
+}
+#endif
+
+/*
* resched_task - mark a task 'to be rescheduled now'.
*
* On UP this means the setting of the need_resched flag, on SMP it
@@ -521,17 +570,15 @@ void resched_task(struct task_struct *p)
if (test_tsk_need_resched(p))
return;
- set_tsk_need_resched(p);
-
cpu = task_cpu(p);
+
if (cpu == smp_processor_id()) {
+ set_tsk_need_resched(p);
set_preempt_need_resched();
return;
}
- /* NEED_RESCHED must be visible before we test polling */
- smp_mb();
- if (!tsk_is_polling(p))
+ if (set_nr_and_not_polling(p))
smp_send_reschedule(cpu);
}
@@ -1320,7 +1367,7 @@ out:
* leave kernel.
*/
if (p->mm && printk_ratelimit()) {
- printk_sched("process %d (%s) no longer affine to cpu%d\n",
+ printk_deferred("process %d (%s) no longer affine to cpu%d\n",
task_pid_nr(p), p->comm, cpu);
}
}
@@ -3002,7 +3049,7 @@ EXPORT_SYMBOL(set_user_nice);
int can_nice(const struct task_struct *p, const int nice)
{
/* convert nice value [19,-20] to rlimit style value [1,40] */
- int nice_rlim = 20 - nice;
+ int nice_rlim = nice_to_rlimit(nice);
return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) ||
capable(CAP_SYS_NICE));
@@ -3026,17 +3073,10 @@ SYSCALL_DEFINE1(nice, int, increment)
* We don't have to worry. Conceptually one call occurs first
* and we have a single winner.
*/
- if (increment < -40)
- increment = -40;
- if (increment > 40)
- increment = 40;
-
+ increment = clamp(increment, -NICE_WIDTH, NICE_WIDTH);
nice = task_nice(current) + increment;
- if (nice < MIN_NICE)
- nice = MIN_NICE;
- if (nice > MAX_NICE)
- nice = MAX_NICE;
+ nice = clamp_val(nice, MIN_NICE, MAX_NICE);
if (increment < 0 && !can_nice(current, nice))
return -EPERM;
@@ -3626,13 +3666,11 @@ static int sched_copy_attr(struct sched_attr __user *uattr,
*/
attr->sched_nice = clamp(attr->sched_nice, MIN_NICE, MAX_NICE);
-out:
- return ret;
+ return 0;
err_size:
put_user(sizeof(*attr), &uattr->size);
- ret = -E2BIG;
- goto out;
+ return -E2BIG;
}
/**
@@ -3792,7 +3830,7 @@ static int sched_read_attr(struct sched_attr __user *uattr,
for (; addr < end; addr++) {
if (*addr)
- goto err_size;
+ return -EFBIG;
}
attr->size = usize;
@@ -3802,12 +3840,7 @@ static int sched_read_attr(struct sched_attr __user *uattr,
if (ret)
return -EFAULT;
-out:
- return ret;
-
-err_size:
- ret = -E2BIG;
- goto out;
+ return 0;
}
/**
@@ -4084,6 +4117,7 @@ static void __cond_resched(void)
int __sched _cond_resched(void)
{
+ rcu_cond_resched();
if (should_resched()) {
__cond_resched();
return 1;
@@ -4102,15 +4136,18 @@ EXPORT_SYMBOL(_cond_resched);
*/
int __cond_resched_lock(spinlock_t *lock)
{
+ bool need_rcu_resched = rcu_should_resched();
int resched = should_resched();
int ret = 0;
lockdep_assert_held(lock);
- if (spin_needbreak(lock) || resched) {
+ if (spin_needbreak(lock) || resched || need_rcu_resched) {
spin_unlock(lock);
if (resched)
__cond_resched();
+ else if (unlikely(need_rcu_resched))
+ rcu_resched();
else
cpu_relax();
ret = 1;
@@ -4124,6 +4161,7 @@ int __sched __cond_resched_softirq(void)
{
BUG_ON(!in_softirq());
+ rcu_cond_resched(); /* BH disabled OK, just recording QSes. */
if (should_resched()) {
local_bh_enable();
__cond_resched();
@@ -5072,10 +5110,20 @@ static struct notifier_block migration_notifier = {
.priority = CPU_PRI_MIGRATION,
};
+static void __cpuinit set_cpu_rq_start_time(void)
+{
+ int cpu = smp_processor_id();
+ struct rq *rq = cpu_rq(cpu);
+ rq->age_stamp = sched_clock_cpu(cpu);
+}
+
static int sched_cpu_active(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
switch (action & ~CPU_TASKS_FROZEN) {
+ case CPU_STARTING:
+ set_cpu_rq_start_time();
+ return NOTIFY_OK;
case CPU_DOWN_FAILED:
set_cpu_active((long)hcpu, true);
return NOTIFY_OK;
@@ -5284,7 +5332,8 @@ static int sd_degenerate(struct sched_domain *sd)
SD_BALANCE_FORK |
SD_BALANCE_EXEC |
SD_SHARE_CPUPOWER |
- SD_SHARE_PKG_RESOURCES)) {
+ SD_SHARE_PKG_RESOURCES |
+ SD_SHARE_POWERDOMAIN)) {
if (sd->groups != sd->groups->next)
return 0;
}
@@ -5315,7 +5364,8 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
SD_BALANCE_EXEC |
SD_SHARE_CPUPOWER |
SD_SHARE_PKG_RESOURCES |
- SD_PREFER_SIBLING);
+ SD_PREFER_SIBLING |
+ SD_SHARE_POWERDOMAIN);
if (nr_node_ids == 1)
pflags &= ~SD_SERIALIZE;
}
@@ -5589,17 +5639,6 @@ static int __init isolated_cpu_setup(char *str)
__setup("isolcpus=", isolated_cpu_setup);
-static const struct cpumask *cpu_cpu_mask(int cpu)
-{
- return cpumask_of_node(cpu_to_node(cpu));
-}
-
-struct sd_data {
- struct sched_domain **__percpu sd;
- struct sched_group **__percpu sg;
- struct sched_group_power **__percpu sgp;
-};
-
struct s_data {
struct sched_domain ** __percpu sd;
struct root_domain *rd;
@@ -5612,21 +5651,6 @@ enum s_alloc {
sa_none,
};
-struct sched_domain_topology_level;
-
-typedef struct sched_domain *(*sched_domain_init_f)(struct sched_domain_topology_level *tl, int cpu);
-typedef const struct cpumask *(*sched_domain_mask_f)(int cpu);
-
-#define SDTL_OVERLAP 0x01
-
-struct sched_domain_topology_level {
- sched_domain_init_f init;
- sched_domain_mask_f mask;
- int flags;
- int numa_level;
- struct sd_data data;
-};
-
/*
* Build an iteration mask that can exclude certain CPUs from the upwards
* domain traversal.
@@ -5794,8 +5818,6 @@ build_sched_groups(struct sched_domain *sd, int cpu)
continue;
group = get_group(i, sdd, &sg);
- cpumask_clear(sched_group_cpus(sg));
- sg->sgp->power = 0;
cpumask_setall(sched_group_mask(sg));
for_each_cpu(j, span) {
@@ -5845,44 +5867,11 @@ static void init_sched_groups_power(int cpu, struct sched_domain *sd)
atomic_set(&sg->sgp->nr_busy_cpus, sg->group_weight);
}
-int __weak arch_sd_sibling_asym_packing(void)
-{
- return 0*SD_ASYM_PACKING;
-}
-
/*
* Initializers for schedule domains
* Non-inlined to reduce accumulated stack pressure in build_sched_domains()
*/
-#ifdef CONFIG_SCHED_DEBUG
-# define SD_INIT_NAME(sd, type) sd->name = #type
-#else
-# define SD_INIT_NAME(sd, type) do { } while (0)
-#endif
-
-#define SD_INIT_FUNC(type) \
-static noinline struct sched_domain * \
-sd_init_##type(struct sched_domain_topology_level *tl, int cpu) \
-{ \
- struct sched_domain *sd = *per_cpu_ptr(tl->data.sd, cpu); \
- *sd = SD_##type##_INIT; \
- SD_INIT_NAME(sd, type); \
- sd->private = &tl->data; \
- return sd; \
-}
-
-SD_INIT_FUNC(CPU)
-#ifdef CONFIG_SCHED_SMT
- SD_INIT_FUNC(SIBLING)
-#endif
-#ifdef CONFIG_SCHED_MC
- SD_INIT_FUNC(MC)
-#endif
-#ifdef CONFIG_SCHED_BOOK
- SD_INIT_FUNC(BOOK)
-#endif
-
static int default_relax_domain_level = -1;
int sched_domain_level_max;
@@ -5970,99 +5959,154 @@ static void claim_allocations(int cpu, struct sched_domain *sd)
*per_cpu_ptr(sdd->sgp, cpu) = NULL;
}
-#ifdef CONFIG_SCHED_SMT
-static const struct cpumask *cpu_smt_mask(int cpu)
-{
- return topology_thread_cpumask(cpu);
-}
-#endif
-
-/*
- * Topology list, bottom-up.
- */
-static struct sched_domain_topology_level default_topology[] = {
-#ifdef CONFIG_SCHED_SMT
- { sd_init_SIBLING, cpu_smt_mask, },
-#endif
-#ifdef CONFIG_SCHED_MC
- { sd_init_MC, cpu_coregroup_mask, },
-#endif
-#ifdef CONFIG_SCHED_BOOK
- { sd_init_BOOK, cpu_book_mask, },
-#endif
- { sd_init_CPU, cpu_cpu_mask, },
- { NULL, },
-};
-
-static struct sched_domain_topology_level *sched_domain_topology = default_topology;
-
-#define for_each_sd_topology(tl) \
- for (tl = sched_domain_topology; tl->init; tl++)
-
#ifdef CONFIG_NUMA
-
static int sched_domains_numa_levels;
static int *sched_domains_numa_distance;
static struct cpumask ***sched_domains_numa_masks;
static int sched_domains_curr_level;
+#endif
-static inline int sd_local_flags(int level)
-{
- if (sched_domains_numa_distance[level] > RECLAIM_DISTANCE)
- return 0;
-
- return SD_BALANCE_EXEC | SD_BALANCE_FORK | SD_WAKE_AFFINE;
-}
+/*
+ * SD_flags allowed in topology descriptions.
+ *
+ * SD_SHARE_CPUPOWER - describes SMT topologies
+ * SD_SHARE_PKG_RESOURCES - describes shared caches
+ * SD_NUMA - describes NUMA topologies
+ * SD_SHARE_POWERDOMAIN - describes shared power domain
+ *
+ * Odd one out:
+ * SD_ASYM_PACKING - describes SMT quirks
+ */
+#define TOPOLOGY_SD_FLAGS \
+ (SD_SHARE_CPUPOWER | \
+ SD_SHARE_PKG_RESOURCES | \
+ SD_NUMA | \
+ SD_ASYM_PACKING | \
+ SD_SHARE_POWERDOMAIN)
static struct sched_domain *
-sd_numa_init(struct sched_domain_topology_level *tl, int cpu)
+sd_init(struct sched_domain_topology_level *tl, int cpu)
{
struct sched_domain *sd = *per_cpu_ptr(tl->data.sd, cpu);
- int level = tl->numa_level;
- int sd_weight = cpumask_weight(
- sched_domains_numa_masks[level][cpu_to_node(cpu)]);
+ int sd_weight, sd_flags = 0;
+
+#ifdef CONFIG_NUMA
+ /*
+ * Ugly hack to pass state to sd_numa_mask()...
+ */
+ sched_domains_curr_level = tl->numa_level;
+#endif
+
+ sd_weight = cpumask_weight(tl->mask(cpu));
+
+ if (tl->sd_flags)
+ sd_flags = (*tl->sd_flags)();
+ if (WARN_ONCE(sd_flags & ~TOPOLOGY_SD_FLAGS,
+ "wrong sd_flags in topology description\n"))
+ sd_flags &= ~TOPOLOGY_SD_FLAGS;
*sd = (struct sched_domain){
.min_interval = sd_weight,
.max_interval = 2*sd_weight,
.busy_factor = 32,
.imbalance_pct = 125,
- .cache_nice_tries = 2,
- .busy_idx = 3,
- .idle_idx = 2,
+
+ .cache_nice_tries = 0,
+ .busy_idx = 0,
+ .idle_idx = 0,
.newidle_idx = 0,
.wake_idx = 0,
.forkexec_idx = 0,
.flags = 1*SD_LOAD_BALANCE
| 1*SD_BALANCE_NEWIDLE
- | 0*SD_BALANCE_EXEC
- | 0*SD_BALANCE_FORK
+ | 1*SD_BALANCE_EXEC
+ | 1*SD_BALANCE_FORK
| 0*SD_BALANCE_WAKE
- | 0*SD_WAKE_AFFINE
+ | 1*SD_WAKE_AFFINE
| 0*SD_SHARE_CPUPOWER
| 0*SD_SHARE_PKG_RESOURCES
- | 1*SD_SERIALIZE
+ | 0*SD_SERIALIZE
| 0*SD_PREFER_SIBLING
- | 1*SD_NUMA
- | sd_local_flags(level)
+ | 0*SD_NUMA
+ | sd_flags
,
+
.last_balance = jiffies,
.balance_interval = sd_weight,
+ .smt_gain = 0,
.max_newidle_lb_cost = 0,
.next_decay_max_lb_cost = jiffies,
+#ifdef CONFIG_SCHED_DEBUG
+ .name = tl->name,
+#endif
};
- SD_INIT_NAME(sd, NUMA);
- sd->private = &tl->data;
/*
- * Ugly hack to pass state to sd_numa_mask()...
+ * Convert topological properties into behaviour.
*/
- sched_domains_curr_level = tl->numa_level;
+
+ if (sd->flags & SD_SHARE_CPUPOWER) {
+ sd->imbalance_pct = 110;
+ sd->smt_gain = 1178; /* ~15% */
+
+ } else if (sd->flags & SD_SHARE_PKG_RESOURCES) {
+ sd->imbalance_pct = 117;
+ sd->cache_nice_tries = 1;
+ sd->busy_idx = 2;
+
+#ifdef CONFIG_NUMA
+ } else if (sd->flags & SD_NUMA) {
+ sd->cache_nice_tries = 2;
+ sd->busy_idx = 3;
+ sd->idle_idx = 2;
+
+ sd->flags |= SD_SERIALIZE;
+ if (sched_domains_numa_distance[tl->numa_level] > RECLAIM_DISTANCE) {
+ sd->flags &= ~(SD_BALANCE_EXEC |
+ SD_BALANCE_FORK |
+ SD_WAKE_AFFINE);
+ }
+
+#endif
+ } else {
+ sd->flags |= SD_PREFER_SIBLING;
+ sd->cache_nice_tries = 1;
+ sd->busy_idx = 2;
+ sd->idle_idx = 1;
+ }
+
+ sd->private = &tl->data;
return sd;
}
+/*
+ * Topology list, bottom-up.
+ */
+static struct sched_domain_topology_level default_topology[] = {
+#ifdef CONFIG_SCHED_SMT
+ { cpu_smt_mask, cpu_smt_flags, SD_INIT_NAME(SMT) },
+#endif
+#ifdef CONFIG_SCHED_MC
+ { cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) },
+#endif
+ { cpu_cpu_mask, SD_INIT_NAME(DIE) },
+ { NULL, },
+};
+
+struct sched_domain_topology_level *sched_domain_topology = default_topology;
+
+#define for_each_sd_topology(tl) \
+ for (tl = sched_domain_topology; tl->mask; tl++)
+
+void set_sched_topology(struct sched_domain_topology_level *tl)
+{
+ sched_domain_topology = tl;
+}
+
+#ifdef CONFIG_NUMA
+
static const struct cpumask *sd_numa_mask(int cpu)
{
return sched_domains_numa_masks[sched_domains_curr_level][cpu_to_node(cpu)];
@@ -6206,7 +6250,10 @@ static void sched_init_numa(void)
}
}
- tl = kzalloc((ARRAY_SIZE(default_topology) + level) *
+ /* Compute default topology size */
+ for (i = 0; sched_domain_topology[i].mask; i++);
+
+ tl = kzalloc((i + level + 1) *
sizeof(struct sched_domain_topology_level), GFP_KERNEL);
if (!tl)
return;
@@ -6214,18 +6261,19 @@ static void sched_init_numa(void)
/*
* Copy the default topology bits..
*/
- for (i = 0; default_topology[i].init; i++)
- tl[i] = default_topology[i];
+ for (i = 0; sched_domain_topology[i].mask; i++)
+ tl[i] = sched_domain_topology[i];
/*
* .. and append 'j' levels of NUMA goodness.
*/
for (j = 0; j < level; i++, j++) {
tl[i] = (struct sched_domain_topology_level){
- .init = sd_numa_init,
.mask = sd_numa_mask,
+ .sd_flags = cpu_numa_flags,
.flags = SDTL_OVERLAP,
.numa_level = j,
+ SD_INIT_NAME(NUMA)
};
}
@@ -6383,7 +6431,7 @@ struct sched_domain *build_sched_domain(struct sched_domain_topology_level *tl,
const struct cpumask *cpu_map, struct sched_domain_attr *attr,
struct sched_domain *child, int cpu)
{
- struct sched_domain *sd = tl->init(tl, cpu);
+ struct sched_domain *sd = sd_init(tl, cpu);
if (!sd)
return child;
@@ -6953,6 +7001,7 @@ void __init sched_init(void)
if (cpu_isolated_map == NULL)
zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
idle_thread_set_boot_cpu();
+ set_cpu_rq_start_time();
#endif
init_sched_fair_class();