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-rw-r--r--kernel/events/core.c90
1 files changed, 64 insertions, 26 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 36babfd20648..ef2d6ea10736 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3,7 +3,7 @@
*
* Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
* Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
- * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
+ * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra
* Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
*
* For licensing details see kernel-base/COPYING
@@ -435,7 +435,7 @@ static inline void update_cgrp_time_from_event(struct perf_event *event)
if (!is_cgroup_event(event))
return;
- cgrp = perf_cgroup_from_task(current);
+ cgrp = perf_cgroup_from_task(current, event->ctx);
/*
* Do not update time when cgroup is not active
*/
@@ -458,7 +458,7 @@ perf_cgroup_set_timestamp(struct task_struct *task,
if (!task || !ctx->nr_cgroups)
return;
- cgrp = perf_cgroup_from_task(task);
+ cgrp = perf_cgroup_from_task(task, ctx);
info = this_cpu_ptr(cgrp->info);
info->timestamp = ctx->timestamp;
}
@@ -489,7 +489,6 @@ static void perf_cgroup_switch(struct task_struct *task, int mode)
* we reschedule only in the presence of cgroup
* constrained events.
*/
- rcu_read_lock();
list_for_each_entry_rcu(pmu, &pmus, entry) {
cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
@@ -522,8 +521,10 @@ static void perf_cgroup_switch(struct task_struct *task, int mode)
* set cgrp before ctxsw in to allow
* event_filter_match() to not have to pass
* task around
+ * we pass the cpuctx->ctx to perf_cgroup_from_task()
+ * because cgorup events are only per-cpu
*/
- cpuctx->cgrp = perf_cgroup_from_task(task);
+ cpuctx->cgrp = perf_cgroup_from_task(task, &cpuctx->ctx);
cpu_ctx_sched_in(cpuctx, EVENT_ALL, task);
}
perf_pmu_enable(cpuctx->ctx.pmu);
@@ -531,8 +532,6 @@ static void perf_cgroup_switch(struct task_struct *task, int mode)
}
}
- rcu_read_unlock();
-
local_irq_restore(flags);
}
@@ -542,17 +541,20 @@ static inline void perf_cgroup_sched_out(struct task_struct *task,
struct perf_cgroup *cgrp1;
struct perf_cgroup *cgrp2 = NULL;
+ rcu_read_lock();
/*
* we come here when we know perf_cgroup_events > 0
+ * we do not need to pass the ctx here because we know
+ * we are holding the rcu lock
*/
- cgrp1 = perf_cgroup_from_task(task);
+ cgrp1 = perf_cgroup_from_task(task, NULL);
/*
* next is NULL when called from perf_event_enable_on_exec()
* that will systematically cause a cgroup_switch()
*/
if (next)
- cgrp2 = perf_cgroup_from_task(next);
+ cgrp2 = perf_cgroup_from_task(next, NULL);
/*
* only schedule out current cgroup events if we know
@@ -561,6 +563,8 @@ static inline void perf_cgroup_sched_out(struct task_struct *task,
*/
if (cgrp1 != cgrp2)
perf_cgroup_switch(task, PERF_CGROUP_SWOUT);
+
+ rcu_read_unlock();
}
static inline void perf_cgroup_sched_in(struct task_struct *prev,
@@ -569,13 +573,16 @@ static inline void perf_cgroup_sched_in(struct task_struct *prev,
struct perf_cgroup *cgrp1;
struct perf_cgroup *cgrp2 = NULL;
+ rcu_read_lock();
/*
* we come here when we know perf_cgroup_events > 0
+ * we do not need to pass the ctx here because we know
+ * we are holding the rcu lock
*/
- cgrp1 = perf_cgroup_from_task(task);
+ cgrp1 = perf_cgroup_from_task(task, NULL);
/* prev can never be NULL */
- cgrp2 = perf_cgroup_from_task(prev);
+ cgrp2 = perf_cgroup_from_task(prev, NULL);
/*
* only need to schedule in cgroup events if we are changing
@@ -584,6 +591,8 @@ static inline void perf_cgroup_sched_in(struct task_struct *prev,
*/
if (cgrp1 != cgrp2)
perf_cgroup_switch(task, PERF_CGROUP_SWIN);
+
+ rcu_read_unlock();
}
static inline int perf_cgroup_connect(int fd, struct perf_event *event,
@@ -4216,7 +4225,14 @@ retry:
goto retry;
}
- __perf_event_period(&pe);
+ if (event->attr.freq) {
+ event->attr.sample_freq = value;
+ } else {
+ event->attr.sample_period = value;
+ event->hw.sample_period = value;
+ }
+
+ local64_set(&event->hw.period_left, 0);
raw_spin_unlock_irq(&ctx->lock);
return 0;
@@ -5667,6 +5683,17 @@ perf_event_aux_ctx(struct perf_event_context *ctx,
}
static void
+perf_event_aux_task_ctx(perf_event_aux_output_cb output, void *data,
+ struct perf_event_context *task_ctx)
+{
+ rcu_read_lock();
+ preempt_disable();
+ perf_event_aux_ctx(task_ctx, output, data);
+ preempt_enable();
+ rcu_read_unlock();
+}
+
+static void
perf_event_aux(perf_event_aux_output_cb output, void *data,
struct perf_event_context *task_ctx)
{
@@ -5675,14 +5702,23 @@ perf_event_aux(perf_event_aux_output_cb output, void *data,
struct pmu *pmu;
int ctxn;
+ /*
+ * If we have task_ctx != NULL we only notify
+ * the task context itself. The task_ctx is set
+ * only for EXIT events before releasing task
+ * context.
+ */
+ if (task_ctx) {
+ perf_event_aux_task_ctx(output, data, task_ctx);
+ return;
+ }
+
rcu_read_lock();
list_for_each_entry_rcu(pmu, &pmus, entry) {
cpuctx = get_cpu_ptr(pmu->pmu_cpu_context);
if (cpuctx->unique_pmu != pmu)
goto next;
perf_event_aux_ctx(&cpuctx->ctx, output, data);
- if (task_ctx)
- goto next;
ctxn = pmu->task_ctx_nr;
if (ctxn < 0)
goto next;
@@ -5692,12 +5728,6 @@ perf_event_aux(perf_event_aux_output_cb output, void *data,
next:
put_cpu_ptr(pmu->pmu_cpu_context);
}
-
- if (task_ctx) {
- preempt_disable();
- perf_event_aux_ctx(task_ctx, output, data);
- preempt_enable();
- }
rcu_read_unlock();
}
@@ -8787,10 +8817,8 @@ static void perf_event_exit_task_context(struct task_struct *child, int ctxn)
struct perf_event_context *child_ctx, *clone_ctx = NULL;
unsigned long flags;
- if (likely(!child->perf_event_ctxp[ctxn])) {
- perf_event_task(child, NULL, 0);
+ if (likely(!child->perf_event_ctxp[ctxn]))
return;
- }
local_irq_save(flags);
/*
@@ -8874,6 +8902,14 @@ void perf_event_exit_task(struct task_struct *child)
for_each_task_context_nr(ctxn)
perf_event_exit_task_context(child, ctxn);
+
+ /*
+ * The perf_event_exit_task_context calls perf_event_task
+ * with child's task_ctx, which generates EXIT events for
+ * child contexts and sets child->perf_event_ctxp[] to NULL.
+ * At this point we need to send EXIT events to cpu contexts.
+ */
+ perf_event_task(child, NULL, 0);
}
static void perf_free_event(struct perf_event *event,
@@ -9452,16 +9488,18 @@ static void perf_cgroup_css_free(struct cgroup_subsys_state *css)
static int __perf_cgroup_move(void *info)
{
struct task_struct *task = info;
+ rcu_read_lock();
perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN);
+ rcu_read_unlock();
return 0;
}
-static void perf_cgroup_attach(struct cgroup_subsys_state *css,
- struct cgroup_taskset *tset)
+static void perf_cgroup_attach(struct cgroup_taskset *tset)
{
struct task_struct *task;
+ struct cgroup_subsys_state *css;
- cgroup_taskset_for_each(task, tset)
+ cgroup_taskset_for_each(task, css, tset)
task_function_call(task, __perf_cgroup_move, task);
}