diff --git a/include/linux/sched.h b/include/linux/sched.h
index b85b10abf770ed59749cda0bd8d679430b826912..1e5f70062a9c2ab79c2f051a78bd44a95180a264 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -137,6 +137,8 @@ extern unsigned long nr_running(void);
extern unsigned long nr_uninterruptible(void);
extern unsigned long nr_active(void);
extern unsigned long nr_iowait(void);
+extern u64 cpu_nr_switches(int cpu);
+extern u64 cpu_nr_migrations(int cpu);
struct seq_file;
struct cfs_rq;
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index f27a7e9f3c417312607f3452ccba4c64b80f99a7..544193cbc47849263b5fbef8b03ca98cd0dbb56c 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -20,6 +20,8 @@
#include <linux/anon_inodes.h>
#include <linux/kernel_stat.h>
#include <linux/perf_counter.h>
+#include <linux/mm.h>
+#include <linux/vmstat.h>
/*
* Each CPU has a list of per CPU counters:
@@ -502,7 +504,6 @@ perf_install_in_context(struct perf_counter_context *ctx,
{
struct task_struct *task = ctx->task;
- counter->ctx = ctx;
if (!task) {
/*
* Per cpu counters are installed via an smp call and
@@ -1417,11 +1418,19 @@ static const struct hw_perf_counter_ops perf_ops_task_clock = {
.read = task_clock_perf_counter_read,
};
-static u64 get_page_faults(void)
+#ifdef CONFIG_VM_EVENT_COUNTERS
+#define cpu_page_faults() __get_cpu_var(vm_event_states).event[PGFAULT]
+#else
+#define cpu_page_faults() 0
+#endif
+
+static u64 get_page_faults(struct perf_counter *counter)
{
- struct task_struct *curr = current;
+ struct task_struct *curr = counter->ctx->task;
- return curr->maj_flt + curr->min_flt;
+ if (curr)
+ return curr->maj_flt + curr->min_flt;
+ return cpu_page_faults();
}
static void page_faults_perf_counter_update(struct perf_counter *counter)
@@ -1430,7 +1439,7 @@ static void page_faults_perf_counter_update(struct perf_counter *counter)
s64 delta;
prev = atomic64_read(&counter->hw.prev_count);
- now = get_page_faults();
+ now = get_page_faults(counter);
atomic64_set(&counter->hw.prev_count, now);
@@ -1446,11 +1455,7 @@ static void page_faults_perf_counter_read(struct perf_counter *counter)
static int page_faults_perf_counter_enable(struct perf_counter *counter)
{
- /*
- * page-faults is a per-task value already,
- * so we dont have to clear it on switch-in.
- */
-
+ atomic64_set(&counter->hw.prev_count, get_page_faults(counter));
return 0;
}
@@ -1465,11 +1470,13 @@ static const struct hw_perf_counter_ops perf_ops_page_faults = {
.read = page_faults_perf_counter_read,
};
-static u64 get_context_switches(void)
+static u64 get_context_switches(struct perf_counter *counter)
{
- struct task_struct *curr = current;
+ struct task_struct *curr = counter->ctx->task;
- return curr->nvcsw + curr->nivcsw;
+ if (curr)
+ return curr->nvcsw + curr->nivcsw;
+ return cpu_nr_switches(smp_processor_id());
}
static void context_switches_perf_counter_update(struct perf_counter *counter)
@@ -1478,7 +1485,7 @@ static void context_switches_perf_counter_update(struct perf_counter *counter)
s64 delta;
prev = atomic64_read(&counter->hw.prev_count);
- now = get_context_switches();
+ now = get_context_switches(counter);
atomic64_set(&counter->hw.prev_count, now);
@@ -1494,11 +1501,7 @@ static void context_switches_perf_counter_read(struct perf_counter *counter)
static int context_switches_perf_counter_enable(struct perf_counter *counter)
{
- /*
- * ->nvcsw + curr->nivcsw is a per-task value already,
- * so we dont have to clear it on switch-in.
- */
-
+ atomic64_set(&counter->hw.prev_count, get_context_switches(counter));
return 0;
}
@@ -1513,9 +1516,13 @@ static const struct hw_perf_counter_ops perf_ops_context_switches = {
.read = context_switches_perf_counter_read,
};
-static inline u64 get_cpu_migrations(void)
+static inline u64 get_cpu_migrations(struct perf_counter *counter)
{
- return current->se.nr_migrations;
+ struct task_struct *curr = counter->ctx->task;
+
+ if (curr)
+ return curr->se.nr_migrations;
+ return cpu_nr_migrations(smp_processor_id());
}
static void cpu_migrations_perf_counter_update(struct perf_counter *counter)
@@ -1524,7 +1531,7 @@ static void cpu_migrations_perf_counter_update(struct perf_counter *counter)
s64 delta;
prev = atomic64_read(&counter->hw.prev_count);
- now = get_cpu_migrations();
+ now = get_cpu_migrations(counter);
atomic64_set(&counter->hw.prev_count, now);
@@ -1540,11 +1547,7 @@ static void cpu_migrations_perf_counter_read(struct perf_counter *counter)
static int cpu_migrations_perf_counter_enable(struct perf_counter *counter)
{
- /*
- * se.nr_migrations is a per-task value already,
- * so we dont have to clear it on switch-in.
- */
-
+ atomic64_set(&counter->hw.prev_count, get_cpu_migrations(counter));
return 0;
}
@@ -1569,7 +1572,14 @@ sw_perf_counter_init(struct perf_counter *counter)
hw_ops = &perf_ops_cpu_clock;
break;
case PERF_COUNT_TASK_CLOCK:
- hw_ops = &perf_ops_task_clock;
+ /*
+ * If the user instantiates this as a per-cpu counter,
+ * use the cpu_clock counter instead.
+ */
+ if (counter->ctx->task)
+ hw_ops = &perf_ops_task_clock;
+ else
+ hw_ops = &perf_ops_cpu_clock;
break;
case PERF_COUNT_PAGE_FAULTS:
hw_ops = &perf_ops_page_faults;
@@ -1592,6 +1602,7 @@ sw_perf_counter_init(struct perf_counter *counter)
static struct perf_counter *
perf_counter_alloc(struct perf_counter_hw_event *hw_event,
int cpu,
+ struct perf_counter_context *ctx,
struct perf_counter *group_leader,
gfp_t gfpflags)
{
@@ -1623,6 +1634,7 @@ perf_counter_alloc(struct perf_counter_hw_event *hw_event,
counter->wakeup_pending = 0;
counter->group_leader = group_leader;
counter->hw_ops = NULL;
+ counter->ctx = ctx;
counter->state = PERF_COUNTER_STATE_INACTIVE;
if (hw_event->disabled)
@@ -1631,7 +1643,7 @@ perf_counter_alloc(struct perf_counter_hw_event *hw_event,
hw_ops = NULL;
if (!hw_event->raw && hw_event->type < 0)
hw_ops = sw_perf_counter_init(counter);
- if (!hw_ops)
+ else
hw_ops = hw_perf_counter_init(counter);
if (!hw_ops) {
@@ -1707,7 +1719,8 @@ sys_perf_counter_open(struct perf_counter_hw_event *hw_event_uptr __user,
}
ret = -EINVAL;
- counter = perf_counter_alloc(&hw_event, cpu, group_leader, GFP_KERNEL);
+ counter = perf_counter_alloc(&hw_event, cpu, ctx, group_leader,
+ GFP_KERNEL);
if (!counter)
goto err_put_context;
@@ -1777,15 +1790,14 @@ inherit_counter(struct perf_counter *parent_counter,
parent_counter = parent_counter->parent;
child_counter = perf_counter_alloc(&parent_counter->hw_event,
- parent_counter->cpu, group_leader,
- GFP_KERNEL);
+ parent_counter->cpu, child_ctx,
+ group_leader, GFP_KERNEL);
if (!child_counter)
return NULL;
/*
* Link it up in the child's context:
*/
- child_counter->ctx = child_ctx;
child_counter->task = child;
list_add_counter(child_counter, child_ctx);
child_ctx->nr_counters++;
diff --git a/kernel/sched.c b/kernel/sched.c
index 8db1a4cf2082ff96894e5618d9cd16cad3d3568b..173768f142ad76d489ce2a5efdd1753ade03a59a 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -558,6 +558,7 @@ struct rq {
struct load_weight load;
unsigned long nr_load_updates;
u64 nr_switches;
+ u64 nr_migrations_in;
struct cfs_rq cfs;
struct rt_rq rt;
@@ -1908,6 +1909,7 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
#endif
if (old_cpu != new_cpu) {
p->se.nr_migrations++;
+ new_rq->nr_migrations_in++;
#ifdef CONFIG_SCHEDSTATS
if (task_hot(p, old_rq->clock, NULL))
schedstat_inc(p, se.nr_forced2_migrations);
@@ -2810,6 +2812,21 @@ unsigned long nr_active(void)
return running + uninterruptible;
}
+/*
+ * Externally visible per-cpu scheduler statistics:
+ * cpu_nr_switches(cpu) - number of context switches on that cpu
+ * cpu_nr_migrations(cpu) - number of migrations into that cpu
+ */
+u64 cpu_nr_switches(int cpu)
+{
+ return cpu_rq(cpu)->nr_switches;
+}
+
+u64 cpu_nr_migrations(int cpu)
+{
+ return cpu_rq(cpu)->nr_migrations_in;
+}
+
/*
* Update rq->cpu_load[] statistics. This function is usually called every
* scheduler tick (TICK_NSEC).