#include <asm/irq_regs.h>
-static atomic_t nr_events __read_mostly;
+atomic_t perf_task_events __read_mostly;
static atomic_t nr_mmap_events __read_mostly;
static atomic_t nr_comm_events __read_mostly;
static atomic_t nr_task_events __read_mostly;
void __weak perf_event_print_debug(void) { }
+extern __weak const char *perf_pmu_name(void)
+{
+ return "pmu";
+}
+
void perf_pmu_disable(struct pmu *pmu)
{
int *count = this_cpu_ptr(pmu->pmu_disable_count);
pmu->pmu_enable(pmu);
}
+static DEFINE_PER_CPU(struct list_head, rotation_list);
+
+/*
+ * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
+ * because they're strictly cpu affine and rotate_start is called with IRQs
+ * disabled, while rotate_context is called from IRQ context.
+ */
static void perf_pmu_rotate_start(struct pmu *pmu)
{
struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
+ struct list_head *head = &__get_cpu_var(rotation_list);
- if (hrtimer_active(&cpuctx->timer))
- return;
-
- __hrtimer_start_range_ns(&cpuctx->timer,
- ns_to_ktime(cpuctx->timer_interval), 0,
- HRTIMER_MODE_REL_PINNED, 0);
-}
-
-static void perf_pmu_rotate_stop(struct pmu *pmu)
-{
- struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
+ WARN_ON(!irqs_disabled());
- hrtimer_cancel(&cpuctx->timer);
+ if (list_empty(&cpuctx->rotation_list))
+ list_add(&cpuctx->rotation_list, head);
}
static void get_ctx(struct perf_event_context *ctx)
{
struct perf_event *group_leader = event->group_leader;
- WARN_ON_ONCE(event->attach_state & PERF_ATTACH_GROUP);
+ /*
+ * We can have double attach due to group movement in perf_event_open.
+ */
+ if (event->attach_state & PERF_ATTACH_GROUP)
+ return;
+
event->attach_state |= PERF_ATTACH_GROUP;
if (group_leader == event)
return event->cpu == -1 || event->cpu == smp_processor_id();
}
-static void
-event_sched_out(struct perf_event *event,
+static int
+__event_sched_out(struct perf_event *event,
struct perf_cpu_context *cpuctx,
struct perf_event_context *ctx)
{
}
if (event->state != PERF_EVENT_STATE_ACTIVE)
- return;
+ return 0;
event->state = PERF_EVENT_STATE_INACTIVE;
if (event->pending_disable) {
event->pending_disable = 0;
event->state = PERF_EVENT_STATE_OFF;
}
- event->tstamp_stopped = ctx->time;
event->pmu->del(event, 0);
event->oncpu = -1;
ctx->nr_active--;
if (event->attr.exclusive || !cpuctx->active_oncpu)
cpuctx->exclusive = 0;
+ return 1;
+}
+
+static void
+event_sched_out(struct perf_event *event,
+ struct perf_cpu_context *cpuctx,
+ struct perf_event_context *ctx)
+{
+ int ret;
+
+ ret = __event_sched_out(event, cpuctx, ctx);
+ if (ret)
+ event->tstamp_stopped = ctx->time;
}
static void
}
static int
-event_sched_in(struct perf_event *event,
+__event_sched_in(struct perf_event *event,
struct perf_cpu_context *cpuctx,
struct perf_event_context *ctx)
{
return -EAGAIN;
}
- event->tstamp_running += ctx->time - event->tstamp_stopped;
-
if (!is_software_event(event))
cpuctx->active_oncpu++;
ctx->nr_active++;
return 0;
}
+static inline int
+event_sched_in(struct perf_event *event,
+ struct perf_cpu_context *cpuctx,
+ struct perf_event_context *ctx)
+{
+ int ret = __event_sched_in(event, cpuctx, ctx);
+ if (ret)
+ return ret;
+ event->tstamp_running += ctx->time - event->tstamp_stopped;
+ return 0;
+}
+
+static void
+group_commit_event_sched_in(struct perf_event *group_event,
+ struct perf_cpu_context *cpuctx,
+ struct perf_event_context *ctx)
+{
+ struct perf_event *event;
+ u64 now = ctx->time;
+
+ group_event->tstamp_running += now - group_event->tstamp_stopped;
+ /*
+ * Schedule in siblings as one group (if any):
+ */
+ list_for_each_entry(event, &group_event->sibling_list, group_entry) {
+ event->tstamp_running += now - event->tstamp_stopped;
+ }
+}
+
static int
group_sched_in(struct perf_event *group_event,
struct perf_cpu_context *cpuctx,
pmu->start_txn(pmu);
- if (event_sched_in(group_event, cpuctx, ctx)) {
+ /*
+ * use __event_sched_in() to delay updating tstamp_running
+ * until the transaction is committed. In case of failure
+ * we will keep an unmodified tstamp_running which is a
+ * requirement to get correct timing information
+ */
+ if (__event_sched_in(group_event, cpuctx, ctx)) {
pmu->cancel_txn(pmu);
return -EAGAIN;
}
* Schedule in siblings as one group (if any):
*/
list_for_each_entry(event, &group_event->sibling_list, group_entry) {
- if (event_sched_in(event, cpuctx, ctx)) {
+ if (__event_sched_in(event, cpuctx, ctx)) {
partial_group = event;
goto group_error;
}
}
- if (!pmu->commit_txn(pmu))
+ if (!pmu->commit_txn(pmu)) {
+ /* commit tstamp_running */
+ group_commit_event_sched_in(group_event, cpuctx, ctx);
return 0;
-
+ }
group_error:
/*
* Groups can be scheduled in as one unit only, so undo any
* partial group before returning:
+ *
+ * use __event_sched_out() to avoid updating tstamp_stopped
+ * because the event never actually ran
*/
list_for_each_entry(event, &group_event->sibling_list, group_entry) {
if (event == partial_group)
break;
- event_sched_out(event, cpuctx, ctx);
+ __event_sched_out(event, cpuctx, ctx);
}
- event_sched_out(group_event, cpuctx, ctx);
+ __event_sched_out(group_event, cpuctx, ctx);
pmu->cancel_txn(pmu);
* accessing the event control register. If a NMI hits, then it will
* not restart the event.
*/
-void perf_event_task_sched_out(struct task_struct *task,
- struct task_struct *next)
+void __perf_event_task_sched_out(struct task_struct *task,
+ struct task_struct *next)
{
int ctxn;
cpuctx->task_ctx = NULL;
}
-/*
- * Called with IRQs disabled
- */
-static void __perf_event_task_sched_out(struct perf_event_context *ctx)
-{
- task_ctx_sched_out(ctx, EVENT_ALL);
-}
-
/*
* Called with IRQs disabled
*/
* accessing the event control register. If a NMI hits, then it will
* keep the event running.
*/
-void perf_event_task_sched_in(struct task_struct *task)
+void __perf_event_task_sched_in(struct task_struct *task)
{
struct perf_event_context *ctx;
int ctxn;
}
/*
- * Cannot race with ->pmu_rotate_start() because this is ran from hardirq
- * context, and ->pmu_rotate_start() is called with irqs disabled (both are
- * cpu affine, so there are no SMP races).
+ * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
+ * because they're strictly cpu affine and rotate_start is called with IRQs
+ * disabled, while rotate_context is called from IRQ context.
*/
-static enum hrtimer_restart perf_event_context_tick(struct hrtimer *timer)
+static void perf_rotate_context(struct perf_cpu_context *cpuctx)
{
- enum hrtimer_restart restart = HRTIMER_NORESTART;
- struct perf_cpu_context *cpuctx;
+ u64 interval = (u64)cpuctx->jiffies_interval * TICK_NSEC;
struct perf_event_context *ctx = NULL;
- int rotate = 0;
-
- cpuctx = container_of(timer, struct perf_cpu_context, timer);
+ int rotate = 0, remove = 1;
if (cpuctx->ctx.nr_events) {
- restart = HRTIMER_RESTART;
+ remove = 0;
if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active)
rotate = 1;
}
ctx = cpuctx->task_ctx;
if (ctx && ctx->nr_events) {
- restart = HRTIMER_RESTART;
+ remove = 0;
if (ctx->nr_events != ctx->nr_active)
rotate = 1;
}
perf_pmu_disable(cpuctx->ctx.pmu);
- perf_ctx_adjust_freq(&cpuctx->ctx, cpuctx->timer_interval);
+ perf_ctx_adjust_freq(&cpuctx->ctx, interval);
if (ctx)
- perf_ctx_adjust_freq(ctx, cpuctx->timer_interval);
+ perf_ctx_adjust_freq(ctx, interval);
if (!rotate)
goto done;
task_ctx_sched_in(ctx, EVENT_FLEXIBLE);
done:
+ if (remove)
+ list_del_init(&cpuctx->rotation_list);
+
perf_pmu_enable(cpuctx->ctx.pmu);
- hrtimer_forward_now(timer, ns_to_ktime(cpuctx->timer_interval));
+}
- return restart;
+void perf_event_task_tick(void)
+{
+ struct list_head *head = &__get_cpu_var(rotation_list);
+ struct perf_cpu_context *cpuctx, *tmp;
+
+ WARN_ON(!irqs_disabled());
+
+ list_for_each_entry_safe(cpuctx, tmp, head, rotation_list) {
+ if (cpuctx->jiffies_interval == 1 ||
+ !(jiffies % cpuctx->jiffies_interval))
+ perf_rotate_context(cpuctx);
+ }
}
static int event_enable_on_exec(struct perf_event *event,
unsigned long flags;
raw_spin_lock_irqsave(&ctx->lock, flags);
- update_context_time(ctx);
+ /*
+ * may read while context is not active
+ * (e.g., thread is blocked), in that case
+ * we cannot update context time
+ */
+ if (ctx->is_active)
+ update_context_time(ctx);
update_event_times(event);
raw_spin_unlock_irqrestore(&ctx->lock, flags);
}
}
}
- put_task_struct(task);
return ctx;
errout:
- put_task_struct(task);
return ERR_PTR(err);
}
kfree(event);
}
-static void perf_pending_sync(struct perf_event *event);
static void perf_buffer_put(struct perf_buffer *buffer);
static void free_event(struct perf_event *event)
{
- perf_pending_sync(event);
+ irq_work_sync(&event->pending);
if (!event->parent) {
- atomic_dec(&nr_events);
+ if (event->attach_state & PERF_ATTACH_TASK)
+ jump_label_dec(&perf_task_events);
if (event->attr.mmap || event->attr.mmap_data)
atomic_dec(&nr_mmap_events);
if (event->attr.comm)
static int perf_event_period(struct perf_event *event, u64 __user *arg)
{
struct perf_event_context *ctx = event->ctx;
- unsigned long size;
int ret = 0;
u64 value;
if (!event->attr.sample_period)
return -EINVAL;
- size = copy_from_user(&value, arg, sizeof(value));
- if (size != sizeof(value))
+ if (copy_from_user(&value, arg, sizeof(value)))
return -EFAULT;
if (!value)
}
}
-/*
- * Pending wakeups
- *
- * Handle the case where we need to wakeup up from NMI (or rq->lock) context.
- *
- * The NMI bit means we cannot possibly take locks. Therefore, maintain a
- * single linked list and use cmpxchg() to add entries lockless.
- */
-
-static void perf_pending_event(struct perf_pending_entry *entry)
+static void perf_pending_event(struct irq_work *entry)
{
struct perf_event *event = container_of(entry,
struct perf_event, pending);
}
}
-#define PENDING_TAIL ((struct perf_pending_entry *)-1UL)
-
-static DEFINE_PER_CPU(struct perf_pending_entry *, perf_pending_head) = {
- PENDING_TAIL,
-};
-
-static void perf_pending_queue(struct perf_pending_entry *entry,
- void (*func)(struct perf_pending_entry *))
-{
- struct perf_pending_entry **head;
-
- if (cmpxchg(&entry->next, NULL, PENDING_TAIL) != NULL)
- return;
-
- entry->func = func;
-
- head = &get_cpu_var(perf_pending_head);
-
- do {
- entry->next = *head;
- } while (cmpxchg(head, entry->next, entry) != entry->next);
-
- set_perf_event_pending();
-
- put_cpu_var(perf_pending_head);
-}
-
-static int __perf_pending_run(void)
-{
- struct perf_pending_entry *list;
- int nr = 0;
-
- list = xchg(&__get_cpu_var(perf_pending_head), PENDING_TAIL);
- while (list != PENDING_TAIL) {
- void (*func)(struct perf_pending_entry *);
- struct perf_pending_entry *entry = list;
-
- list = list->next;
-
- func = entry->func;
- entry->next = NULL;
- /*
- * Ensure we observe the unqueue before we issue the wakeup,
- * so that we won't be waiting forever.
- * -- see perf_not_pending().
- */
- smp_wmb();
-
- func(entry);
- nr++;
- }
-
- return nr;
-}
-
-static inline int perf_not_pending(struct perf_event *event)
-{
- /*
- * If we flush on whatever cpu we run, there is a chance we don't
- * need to wait.
- */
- get_cpu();
- __perf_pending_run();
- put_cpu();
-
- /*
- * Ensure we see the proper queue state before going to sleep
- * so that we do not miss the wakeup. -- see perf_pending_handle()
- */
- smp_rmb();
- return event->pending.next == NULL;
-}
-
-static void perf_pending_sync(struct perf_event *event)
-{
- wait_event(event->waitq, perf_not_pending(event));
-}
-
-void perf_event_do_pending(void)
-{
- __perf_pending_run();
-}
-
/*
* We assume there is only KVM supporting the callbacks.
* Later on, we might change it to a list if there is
if (handle->nmi) {
handle->event->pending_wakeup = 1;
- perf_pending_queue(&handle->event->pending,
- perf_pending_event);
+ irq_work_queue(&handle->event->pending);
} else
perf_event_wakeup(handle->event);
}
rcu_read_lock();
list_for_each_entry_rcu(pmu, &pmus, entry) {
- cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
+ cpuctx = get_cpu_ptr(pmu->pmu_cpu_context);
perf_event_task_ctx(&cpuctx->ctx, task_event);
ctx = task_event->task_ctx;
if (!ctx) {
ctxn = pmu->task_ctx_nr;
if (ctxn < 0)
- continue;
+ goto next;
ctx = rcu_dereference(current->perf_event_ctxp[ctxn]);
}
if (ctx)
perf_event_task_ctx(ctx, task_event);
+next:
+ put_cpu_ptr(pmu->pmu_cpu_context);
}
rcu_read_unlock();
}
rcu_read_lock();
list_for_each_entry_rcu(pmu, &pmus, entry) {
- cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
+ cpuctx = get_cpu_ptr(pmu->pmu_cpu_context);
perf_event_comm_ctx(&cpuctx->ctx, comm_event);
ctxn = pmu->task_ctx_nr;
if (ctxn < 0)
- continue;
+ goto next;
ctx = rcu_dereference(current->perf_event_ctxp[ctxn]);
if (ctx)
perf_event_comm_ctx(ctx, comm_event);
+next:
+ put_cpu_ptr(pmu->pmu_cpu_context);
}
rcu_read_unlock();
}
rcu_read_lock();
list_for_each_entry_rcu(pmu, &pmus, entry) {
- cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
+ cpuctx = get_cpu_ptr(pmu->pmu_cpu_context);
perf_event_mmap_ctx(&cpuctx->ctx, mmap_event,
vma->vm_flags & VM_EXEC);
ctxn = pmu->task_ctx_nr;
if (ctxn < 0)
- continue;
+ goto next;
ctx = rcu_dereference(current->perf_event_ctxp[ctxn]);
if (ctx) {
perf_event_mmap_ctx(ctx, mmap_event,
vma->vm_flags & VM_EXEC);
}
+next:
+ put_cpu_ptr(pmu->pmu_cpu_context);
}
rcu_read_unlock();
event->pending_kill = POLL_HUP;
if (nmi) {
event->pending_disable = 1;
- perf_pending_queue(&event->pending,
- perf_pending_event);
+ irq_work_queue(&event->pending);
} else
perf_event_disable(event);
}
WARN_ON(event->parent);
- atomic_dec(&perf_swevent_enabled[event_id]);
+ jump_label_dec(&perf_swevent_enabled[event_id]);
swevent_hlist_put(event);
}
if (err)
return err;
- atomic_inc(&perf_swevent_enabled[event_id]);
+ jump_label_inc(&perf_swevent_enabled[event_id]);
event->destroy = sw_perf_event_destroy;
}
__perf_event_init_context(&cpuctx->ctx);
cpuctx->ctx.type = cpu_context;
cpuctx->ctx.pmu = pmu;
- cpuctx->timer_interval = TICK_NSEC;
- hrtimer_init(&cpuctx->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
- cpuctx->timer.function = perf_event_context_tick;
+ cpuctx->jiffies_interval = 1;
+ INIT_LIST_HEAD(&cpuctx->rotation_list);
}
got_cpu_context:
*/
static struct perf_event *
perf_event_alloc(struct perf_event_attr *attr, int cpu,
- struct perf_event *group_leader,
- struct perf_event *parent_event,
- perf_overflow_handler_t overflow_handler)
+ struct task_struct *task,
+ struct perf_event *group_leader,
+ struct perf_event *parent_event,
+ perf_overflow_handler_t overflow_handler)
{
struct pmu *pmu;
struct perf_event *event;
INIT_LIST_HEAD(&event->event_entry);
INIT_LIST_HEAD(&event->sibling_list);
init_waitqueue_head(&event->waitq);
+ init_irq_work(&event->pending, perf_pending_event);
mutex_init(&event->mmap_mutex);
event->state = PERF_EVENT_STATE_INACTIVE;
+ if (task) {
+ event->attach_state = PERF_ATTACH_TASK;
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+ /*
+ * hw_breakpoint is a bit difficult here..
+ */
+ if (attr->type == PERF_TYPE_BREAKPOINT)
+ event->hw.bp_target = task;
+#endif
+ }
+
if (!overflow_handler && parent_event)
overflow_handler = parent_event->overflow_handler;
event->pmu = pmu;
if (!event->parent) {
- atomic_inc(&nr_events);
+ if (event->attach_state & PERF_ATTACH_TASK)
+ jump_label_inc(&perf_task_events);
if (event->attr.mmap || event->attr.mmap_data)
atomic_inc(&nr_mmap_events);
if (event->attr.comm)
group_leader = NULL;
}
- event = perf_event_alloc(&attr, cpu, group_leader, NULL, NULL);
+ if (pid != -1) {
+ task = find_lively_task_by_vpid(pid);
+ if (IS_ERR(task)) {
+ err = PTR_ERR(task);
+ goto err_group_fd;
+ }
+ }
+
+ event = perf_event_alloc(&attr, cpu, task, group_leader, NULL, NULL);
if (IS_ERR(event)) {
err = PTR_ERR(event);
- goto err_fd;
+ goto err_task;
}
/*
}
}
- if (pid != -1)
- task = find_lively_task_by_vpid(pid);
-
/*
* Get the target context (task or percpu):
*/
ctx = find_get_context(pmu, task, cpu);
if (IS_ERR(ctx)) {
err = PTR_ERR(ctx);
- goto err_group_fd;
+ goto err_alloc;
}
/*
err_context:
put_ctx(ctx);
+err_alloc:
+ free_event(event);
+err_task:
+ if (task)
+ put_task_struct(task);
err_group_fd:
fput_light(group_file, fput_needed);
- free_event(event);
err_fd:
put_unused_fd(event_fd);
return err;
* Get the target context (task or percpu):
*/
- event = perf_event_alloc(attr, cpu, NULL, NULL, overflow_handler);
+ event = perf_event_alloc(attr, cpu, task, NULL, NULL, overflow_handler);
if (IS_ERR(event)) {
err = PTR_ERR(event);
goto err;
* our context.
*/
child_ctx = child->perf_event_ctxp[ctxn];
- __perf_event_task_sched_out(child_ctx);
+ task_ctx_sched_out(child_ctx, EVENT_ALL);
/*
* Take the context lock here so that if find_get_context is
child_event = perf_event_alloc(&parent_event->attr,
parent_event->cpu,
+ child,
group_leader, parent_event,
NULL);
if (IS_ERR(child_event))
for_each_possible_cpu(cpu) {
swhash = &per_cpu(swevent_htable, cpu);
mutex_init(&swhash->hlist_mutex);
+ INIT_LIST_HEAD(&per_cpu(rotation_list, cpu));
}
}
}
#ifdef CONFIG_HOTPLUG_CPU
+static void perf_pmu_rotate_stop(struct pmu *pmu)
+{
+ struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
+
+ WARN_ON(!irqs_disabled());
+
+ list_del_init(&cpuctx->rotation_list);
+}
+
static void __perf_event_exit_context(void *__info)
{
struct perf_event_context *ctx = __info;
projects / firefly-linux-kernel-4.4.55.git / blobdiff