if (!f.file)
return -EBADF;
- css = css_tryget_from_dir(f.file->f_dentry, &perf_event_cgrp_subsys);
+ css = css_tryget_online_from_dir(f.file->f_dentry,
+ &perf_event_cgrp_subsys);
if (IS_ERR(css)) {
ret = PTR_ERR(css);
goto out;
local_irq_restore(flags);
}
+void perf_event_exec(void)
+{
+ struct perf_event_context *ctx;
+ int ctxn;
+
+ rcu_read_lock();
+ for_each_task_context_nr(ctxn) {
+ ctx = current->perf_event_ctxp[ctxn];
+ if (!ctx)
+ continue;
+
+ perf_event_enable_on_exec(ctx);
+ }
+ rcu_read_unlock();
+}
+
/*
* Cross CPU call to read the hardware event
*/
}
static void ring_buffer_put(struct ring_buffer *rb);
-static void ring_buffer_detach(struct perf_event *event, struct ring_buffer *rb);
+static void ring_buffer_attach(struct perf_event *event,
+ struct ring_buffer *rb);
static void unaccount_event_cpu(struct perf_event *event, int cpu)
{
unaccount_event(event);
if (event->rb) {
- struct ring_buffer *rb;
-
/*
* Can happen when we close an event with re-directed output.
*
* over us; possibly making our ring_buffer_put() the last.
*/
mutex_lock(&event->mmap_mutex);
- rb = event->rb;
- if (rb) {
- rcu_assign_pointer(event->rb, NULL);
- ring_buffer_detach(event, rb);
- ring_buffer_put(rb); /* could be last */
- }
+ ring_buffer_attach(event, NULL);
mutex_unlock(&event->mmap_mutex);
}
static void ring_buffer_attach(struct perf_event *event,
struct ring_buffer *rb)
{
+ struct ring_buffer *old_rb = NULL;
unsigned long flags;
- if (!list_empty(&event->rb_entry))
- return;
+ if (event->rb) {
+ /*
+ * Should be impossible, we set this when removing
+ * event->rb_entry and wait/clear when adding event->rb_entry.
+ */
+ WARN_ON_ONCE(event->rcu_pending);
- spin_lock_irqsave(&rb->event_lock, flags);
- if (list_empty(&event->rb_entry))
- list_add(&event->rb_entry, &rb->event_list);
- spin_unlock_irqrestore(&rb->event_lock, flags);
-}
+ old_rb = event->rb;
+ event->rcu_batches = get_state_synchronize_rcu();
+ event->rcu_pending = 1;
-static void ring_buffer_detach(struct perf_event *event, struct ring_buffer *rb)
-{
- unsigned long flags;
+ spin_lock_irqsave(&old_rb->event_lock, flags);
+ list_del_rcu(&event->rb_entry);
+ spin_unlock_irqrestore(&old_rb->event_lock, flags);
+ }
- if (list_empty(&event->rb_entry))
- return;
+ if (event->rcu_pending && rb) {
+ cond_synchronize_rcu(event->rcu_batches);
+ event->rcu_pending = 0;
+ }
- spin_lock_irqsave(&rb->event_lock, flags);
- list_del_init(&event->rb_entry);
- wake_up_all(&event->waitq);
- spin_unlock_irqrestore(&rb->event_lock, flags);
+ if (rb) {
+ spin_lock_irqsave(&rb->event_lock, flags);
+ list_add_rcu(&event->rb_entry, &rb->event_list);
+ spin_unlock_irqrestore(&rb->event_lock, flags);
+ }
+
+ rcu_assign_pointer(event->rb, rb);
+
+ if (old_rb) {
+ ring_buffer_put(old_rb);
+ /*
+ * Since we detached before setting the new rb, so that we
+ * could attach the new rb, we could have missed a wakeup.
+ * Provide it now.
+ */
+ wake_up_all(&event->waitq);
+ }
}
static void ring_buffer_wakeup(struct perf_event *event)
{
struct perf_event *event = vma->vm_file->private_data;
- struct ring_buffer *rb = event->rb;
+ struct ring_buffer *rb = ring_buffer_get(event);
struct user_struct *mmap_user = rb->mmap_user;
int mmap_locked = rb->mmap_locked;
unsigned long size = perf_data_size(rb);
atomic_dec(&rb->mmap_count);
if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex))
- return;
+ goto out_put;
- /* Detach current event from the buffer. */
- rcu_assign_pointer(event->rb, NULL);
- ring_buffer_detach(event, rb);
+ ring_buffer_attach(event, NULL);
mutex_unlock(&event->mmap_mutex);
/* If there's still other mmap()s of this buffer, we're done. */
- if (atomic_read(&rb->mmap_count)) {
- ring_buffer_put(rb); /* can't be last */
- return;
- }
+ if (atomic_read(&rb->mmap_count))
+ goto out_put;
/*
* No other mmap()s, detach from all other events that might redirect
* still restart the iteration to make sure we're not now
* iterating the wrong list.
*/
- if (event->rb == rb) {
- rcu_assign_pointer(event->rb, NULL);
- ring_buffer_detach(event, rb);
- ring_buffer_put(rb); /* can't be last, we still have one */
- }
+ if (event->rb == rb)
+ ring_buffer_attach(event, NULL);
+
mutex_unlock(&event->mmap_mutex);
put_event(event);
vma->vm_mm->pinned_vm -= mmap_locked;
free_uid(mmap_user);
+out_put:
ring_buffer_put(rb); /* could be last */
}
vma->vm_mm->pinned_vm += extra;
ring_buffer_attach(event, rb);
- rcu_assign_pointer(event->rb, rb);
perf_event_init_userpage(event);
perf_event_update_userpage(event);
NULL);
}
-void perf_event_comm(struct task_struct *task)
+void perf_event_comm(struct task_struct *task, bool exec)
{
struct perf_comm_event comm_event;
- struct perf_event_context *ctx;
- int ctxn;
-
- rcu_read_lock();
- for_each_task_context_nr(ctxn) {
- ctx = task->perf_event_ctxp[ctxn];
- if (!ctx)
- continue;
-
- perf_event_enable_on_exec(ctx);
- }
- rcu_read_unlock();
if (!atomic_read(&nr_comm_events))
return;
.event_id = {
.header = {
.type = PERF_RECORD_COMM,
- .misc = 0,
+ .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0,
/* .size */
},
/* .pid */
/* Recursion avoidance in each contexts */
int recursion[PERF_NR_CONTEXTS];
+
+ /* Keeps track of cpu being initialized/exited */
+ bool online;
};
static DEFINE_PER_CPU(struct swevent_htable, swevent_htable);
hwc->state = !(flags & PERF_EF_START);
head = find_swevent_head(swhash, event);
- if (WARN_ON_ONCE(!head))
+ if (!head) {
+ /*
+ * We can race with cpu hotplug code. Do not
+ * WARN if the cpu just got unplugged.
+ */
+ WARN_ON_ONCE(swhash->online);
return -EINVAL;
+ }
hlist_add_head_rcu(&event->hlist_entry, head);
static int
perf_event_set_output(struct perf_event *event, struct perf_event *output_event)
{
- struct ring_buffer *rb = NULL, *old_rb = NULL;
+ struct ring_buffer *rb = NULL;
int ret = -EINVAL;
if (!output_event)
if (atomic_read(&event->mmap_count))
goto unlock;
- old_rb = event->rb;
-
if (output_event) {
/* get the rb we want to redirect to */
rb = ring_buffer_get(output_event);
goto unlock;
}
- if (old_rb)
- ring_buffer_detach(event, old_rb);
-
- if (rb)
- ring_buffer_attach(event, rb);
-
- rcu_assign_pointer(event->rb, rb);
-
- if (old_rb) {
- ring_buffer_put(old_rb);
- /*
- * Since we detached before setting the new rb, so that we
- * could attach the new rb, we could have missed a wakeup.
- * Provide it now.
- */
- wake_up_all(&event->waitq);
- }
+ ring_buffer_attach(event, rb);
ret = 0;
unlock:
if (attr.freq) {
if (attr.sample_freq > sysctl_perf_event_sample_rate)
return -EINVAL;
+ } else {
+ if (attr.sample_period & (1ULL << 63))
+ return -EINVAL;
}
/*
}
}
+ if (is_sampling_event(event)) {
+ if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) {
+ err = -ENOTSUPP;
+ goto err_alloc;
+ }
+ }
+
account_event(event);
/*
static void perf_event_exit_task_context(struct task_struct *child, int ctxn)
{
- struct perf_event *child_event;
+ struct perf_event *child_event, *next;
struct perf_event_context *child_ctx;
unsigned long flags;
*/
mutex_lock(&child_ctx->mutex);
- list_for_each_entry_rcu(child_event, &child_ctx->event_list, event_entry)
+ list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry)
__perf_event_exit_task(child_event, child_ctx, child);
mutex_unlock(&child_ctx->mutex);
struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
mutex_lock(&swhash->hlist_mutex);
+ swhash->online = true;
if (swhash->hlist_refcount > 0) {
struct swevent_hlist *hlist;
perf_event_exit_cpu_context(cpu);
mutex_lock(&swhash->hlist_mutex);
+ swhash->online = false;
swevent_hlist_release(swhash);
mutex_unlock(&swhash->hlist_mutex);
}
git.samba.org / jlayton / linux.git / blobdiff