#include <linux/file.h>
#include <linux/poll.h>
#include <linux/sysfs.h>
-#include <linux/ptrace.h>
+#include <linux/dcache.h>
#include <linux/percpu.h>
+#include <linux/ptrace.h>
#include <linux/vmstat.h>
#include <linux/hardirq.h>
#include <linux/rculist.h>
#include <linux/anon_inodes.h>
#include <linux/kernel_stat.h>
#include <linux/perf_counter.h>
-#include <linux/dcache.h>
#include <asm/irq_regs.h>
static int perf_overcommit __read_mostly = 1;
static atomic_t nr_counters __read_mostly;
-static atomic_t nr_mmap_tracking __read_mostly;
-static atomic_t nr_munmap_tracking __read_mostly;
-static atomic_t nr_comm_tracking __read_mostly;
+static atomic_t nr_mmap_counters __read_mostly;
+static atomic_t nr_comm_counters __read_mostly;
+static atomic_t nr_task_counters __read_mostly;
+
+/*
+ * perf counter paranoia level:
+ * 0 - not paranoid
+ * 1 - disallow cpu counters to unpriv
+ * 2 - disallow kernel profiling to unpriv
+ */
+int sysctl_perf_counter_paranoid __read_mostly;
+
+static inline bool perf_paranoid_cpu(void)
+{
+ return sysctl_perf_counter_paranoid > 0;
+}
+
+static inline bool perf_paranoid_kernel(void)
+{
+ return sysctl_perf_counter_paranoid > 1;
+}
-int sysctl_perf_counter_priv __read_mostly; /* do we need to be privileged */
int sysctl_perf_counter_mlock __read_mostly = 512; /* 'free' kb per user */
/*
+ * max perf counter sample rate
+ */
+int sysctl_perf_counter_sample_rate __read_mostly = 100000;
+
+static atomic64_t perf_counter_id;
+
+/*
* Lock for (sysadmin-configurable) counter reservations:
*/
static DEFINE_SPINLOCK(perf_resource_lock);
void __weak hw_perf_enable(void) { barrier(); }
void __weak hw_perf_counter_setup(int cpu) { barrier(); }
-int __weak hw_perf_group_sched_in(struct perf_counter *group_leader,
+void __weak hw_perf_counter_setup_online(int cpu) { barrier(); }
+
+int __weak
+hw_perf_group_sched_in(struct perf_counter *group_leader,
struct perf_cpu_context *cpuctx,
struct perf_counter_context *ctx, int cpu)
{
static void get_ctx(struct perf_counter_context *ctx)
{
- atomic_inc(&ctx->refcount);
+ WARN_ON(!atomic_inc_not_zero(&ctx->refcount));
+}
+
+static void free_ctx(struct rcu_head *head)
+{
+ struct perf_counter_context *ctx;
+
+ ctx = container_of(head, struct perf_counter_context, rcu_head);
+ kfree(ctx);
}
static void put_ctx(struct perf_counter_context *ctx)
if (atomic_dec_and_test(&ctx->refcount)) {
if (ctx->parent_ctx)
put_ctx(ctx->parent_ctx);
- kfree(ctx);
+ if (ctx->task)
+ put_task_struct(ctx->task);
+ call_rcu(&ctx->rcu_head, free_ctx);
+ }
+}
+
+static void unclone_ctx(struct perf_counter_context *ctx)
+{
+ if (ctx->parent_ctx) {
+ put_ctx(ctx->parent_ctx);
+ ctx->parent_ctx = NULL;
+ }
+}
+
+/*
+ * If we inherit counters we want to return the parent counter id
+ * to userspace.
+ */
+static u64 primary_counter_id(struct perf_counter *counter)
+{
+ u64 id = counter->id;
+
+ if (counter->parent)
+ id = counter->parent->id;
+
+ return id;
+}
+
+/*
+ * Get the perf_counter_context for a task and lock it.
+ * This has to cope with with the fact that until it is locked,
+ * the context could get moved to another task.
+ */
+static struct perf_counter_context *
+perf_lock_task_context(struct task_struct *task, unsigned long *flags)
+{
+ struct perf_counter_context *ctx;
+
+ rcu_read_lock();
+ retry:
+ ctx = rcu_dereference(task->perf_counter_ctxp);
+ if (ctx) {
+ /*
+ * If this context is a clone of another, it might
+ * get swapped for another underneath us by
+ * perf_counter_task_sched_out, though the
+ * rcu_read_lock() protects us from any context
+ * getting freed. Lock the context and check if it
+ * got swapped before we could get the lock, and retry
+ * if so. If we locked the right context, then it
+ * can't get swapped on us any more.
+ */
+ spin_lock_irqsave(&ctx->lock, *flags);
+ if (ctx != rcu_dereference(task->perf_counter_ctxp)) {
+ spin_unlock_irqrestore(&ctx->lock, *flags);
+ goto retry;
+ }
+
+ if (!atomic_inc_not_zero(&ctx->refcount)) {
+ spin_unlock_irqrestore(&ctx->lock, *flags);
+ ctx = NULL;
+ }
+ }
+ rcu_read_unlock();
+ return ctx;
+}
+
+/*
+ * Get the context for a task and increment its pin_count so it
+ * can't get swapped to another task. This also increments its
+ * reference count so that the context can't get freed.
+ */
+static struct perf_counter_context *perf_pin_task_context(struct task_struct *task)
+{
+ struct perf_counter_context *ctx;
+ unsigned long flags;
+
+ ctx = perf_lock_task_context(task, &flags);
+ if (ctx) {
+ ++ctx->pin_count;
+ spin_unlock_irqrestore(&ctx->lock, flags);
}
+ return ctx;
+}
+
+static void perf_unpin_context(struct perf_counter_context *ctx)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&ctx->lock, flags);
+ --ctx->pin_count;
+ spin_unlock_irqrestore(&ctx->lock, flags);
+ put_ctx(ctx);
}
/*
list_add_rcu(&counter->event_entry, &ctx->event_list);
ctx->nr_counters++;
- if (counter->state >= PERF_COUNTER_STATE_INACTIVE)
- ctx->nr_enabled++;
+ if (counter->attr.inherit_stat)
+ ctx->nr_stat++;
}
/*
if (list_empty(&counter->list_entry))
return;
ctx->nr_counters--;
- if (counter->state >= PERF_COUNTER_STATE_INACTIVE)
- ctx->nr_enabled--;
+ if (counter->attr.inherit_stat)
+ ctx->nr_stat--;
list_del_init(&counter->list_entry);
list_del_rcu(&counter->event_entry);
return;
counter->state = PERF_COUNTER_STATE_INACTIVE;
+ if (counter->pending_disable) {
+ counter->pending_disable = 0;
+ counter->state = PERF_COUNTER_STATE_OFF;
+ }
counter->tstamp_stopped = ctx->time;
counter->pmu->disable(counter);
counter->oncpu = -1;
if (!is_software_counter(counter))
cpuctx->active_oncpu--;
ctx->nr_active--;
- if (counter->hw_event.exclusive || !cpuctx->active_oncpu)
+ if (counter->attr.exclusive || !cpuctx->active_oncpu)
cpuctx->exclusive = 0;
}
list_for_each_entry(counter, &group_counter->sibling_list, list_entry)
counter_sched_out(counter, cpuctx, ctx);
- if (group_counter->hw_event.exclusive)
+ if (group_counter->attr.exclusive)
cpuctx->exclusive = 0;
}
/*
- * Mark this context as not being a clone of another.
- * Called when counters are added to or removed from this context.
- * We also increment our generation number so that anything that
- * was cloned from this context before this will not match anything
- * cloned from this context after this.
- */
-static void unclone_ctx(struct perf_counter_context *ctx)
-{
- ++ctx->generation;
- if (!ctx->parent_ctx)
- return;
- put_ctx(ctx->parent_ctx);
- ctx->parent_ctx = NULL;
-}
-
-/*
* Cross CPU call to remove a performance counter
*
* We disable the counter on the hardware level first. After that we
struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
struct perf_counter *counter = info;
struct perf_counter_context *ctx = counter->ctx;
- unsigned long flags;
/*
* If this is a task context, we need to check whether it is
if (ctx->task && cpuctx->task_ctx != ctx)
return;
- spin_lock_irqsave(&ctx->lock, flags);
+ spin_lock(&ctx->lock);
/*
* Protect the list operation against NMI by disabling the
* counters on a global level.
}
perf_enable();
- spin_unlock_irqrestore(&ctx->lock, flags);
+ spin_unlock(&ctx->lock);
}
*
* CPU counters are removed with a smp call. For task counters we only
* call when the task is on a CPU.
+ *
+ * If counter->ctx is a cloned context, callers must make sure that
+ * every task struct that counter->ctx->task could possibly point to
+ * remains valid. This is OK when called from perf_release since
+ * that only calls us on the top-level context, which can't be a clone.
+ * When called from perf_counter_exit_task, it's OK because the
+ * context has been detached from its task.
*/
static void perf_counter_remove_from_context(struct perf_counter *counter)
{
struct perf_counter_context *ctx = counter->ctx;
struct task_struct *task = ctx->task;
- unclone_ctx(ctx);
if (!task) {
/*
* Per cpu counters are removed via an smp call and
struct perf_counter *counter = info;
struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
struct perf_counter_context *ctx = counter->ctx;
- unsigned long flags;
/*
* If this is a per-task counter, need to check whether this
if (ctx->task && cpuctx->task_ctx != ctx)
return;
- spin_lock_irqsave(&ctx->lock, flags);
+ spin_lock(&ctx->lock);
/*
* If the counter is on, turn it off.
else
counter_sched_out(counter, cpuctx, ctx);
counter->state = PERF_COUNTER_STATE_OFF;
- ctx->nr_enabled--;
}
- spin_unlock_irqrestore(&ctx->lock, flags);
+ spin_unlock(&ctx->lock);
}
/*
* Disable a counter.
+ *
+ * If counter->ctx is a cloned context, callers must make sure that
+ * every task struct that counter->ctx->task could possibly point to
+ * remains valid. This condition is satisifed when called through
+ * perf_counter_for_each_child or perf_counter_for_each because they
+ * hold the top-level counter's child_mutex, so any descendant that
+ * goes to exit will block in sync_child_counter.
+ * When called from perf_pending_counter it's OK because counter->ctx
+ * is the current context on this CPU and preemption is disabled,
+ * hence we can't get into perf_counter_task_sched_out for this context.
*/
static void perf_counter_disable(struct perf_counter *counter)
{
if (counter->state == PERF_COUNTER_STATE_INACTIVE) {
update_counter_times(counter);
counter->state = PERF_COUNTER_STATE_OFF;
- ctx->nr_enabled--;
}
spin_unlock_irq(&ctx->lock);
cpuctx->active_oncpu++;
ctx->nr_active++;
- if (counter->hw_event.exclusive)
+ if (counter->attr.exclusive)
cpuctx->exclusive = 1;
return 0;
if (ret)
return ret < 0 ? ret : 0;
- group_counter->prev_state = group_counter->state;
if (counter_sched_in(group_counter, cpuctx, ctx, cpu))
return -EAGAIN;
* Schedule in siblings as one group (if any):
*/
list_for_each_entry(counter, &group_counter->sibling_list, list_entry) {
- counter->prev_state = counter->state;
if (counter_sched_in(counter, cpuctx, ctx, cpu)) {
partial_group = counter;
goto group_error;
* If this group is exclusive and there are already
* counters on the CPU, it can't go on.
*/
- if (counter->hw_event.exclusive && cpuctx->active_oncpu)
+ if (counter->attr.exclusive && cpuctx->active_oncpu)
return 0;
/*
* Otherwise, try to add it if all previous groups were able
struct perf_counter_context *ctx)
{
list_add_counter(counter, ctx);
- counter->prev_state = PERF_COUNTER_STATE_OFF;
counter->tstamp_enabled = ctx->time;
counter->tstamp_running = ctx->time;
counter->tstamp_stopped = ctx->time;
struct perf_counter_context *ctx = counter->ctx;
struct perf_counter *leader = counter->group_leader;
int cpu = smp_processor_id();
- unsigned long flags;
int err;
/*
cpuctx->task_ctx = ctx;
}
- spin_lock_irqsave(&ctx->lock, flags);
+ spin_lock(&ctx->lock);
ctx->is_active = 1;
update_context_time(ctx);
*/
if (leader != counter)
group_sched_out(leader, cpuctx, ctx);
- if (leader->hw_event.pinned) {
+ if (leader->attr.pinned) {
update_group_times(leader);
leader->state = PERF_COUNTER_STATE_ERROR;
}
unlock:
perf_enable();
- spin_unlock_irqrestore(&ctx->lock, flags);
+ spin_unlock(&ctx->lock);
}
/*
struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
struct perf_counter_context *ctx = counter->ctx;
struct perf_counter *leader = counter->group_leader;
- unsigned long flags;
int err;
/*
cpuctx->task_ctx = ctx;
}
- spin_lock_irqsave(&ctx->lock, flags);
+ spin_lock(&ctx->lock);
ctx->is_active = 1;
update_context_time(ctx);
- counter->prev_state = counter->state;
if (counter->state >= PERF_COUNTER_STATE_INACTIVE)
goto unlock;
counter->state = PERF_COUNTER_STATE_INACTIVE;
counter->tstamp_enabled = ctx->time - counter->total_time_enabled;
- ctx->nr_enabled++;
/*
* If the counter is in a group and isn't the group leader,
*/
if (leader != counter)
group_sched_out(leader, cpuctx, ctx);
- if (leader->hw_event.pinned) {
+ if (leader->attr.pinned) {
update_group_times(leader);
leader->state = PERF_COUNTER_STATE_ERROR;
}
}
unlock:
- spin_unlock_irqrestore(&ctx->lock, flags);
+ spin_unlock(&ctx->lock);
}
/*
* Enable a counter.
+ *
+ * If counter->ctx is a cloned context, callers must make sure that
+ * every task struct that counter->ctx->task could possibly point to
+ * remains valid. This condition is satisfied when called through
+ * perf_counter_for_each_child or perf_counter_for_each as described
+ * for perf_counter_disable.
*/
static void perf_counter_enable(struct perf_counter *counter)
{
counter->state = PERF_COUNTER_STATE_INACTIVE;
counter->tstamp_enabled =
ctx->time - counter->total_time_enabled;
- ctx->nr_enabled++;
}
out:
spin_unlock_irq(&ctx->lock);
/*
* not supported on inherited counters
*/
- if (counter->hw_event.inherit)
+ if (counter->attr.inherit)
return -EINVAL;
atomic_add(refresh, &counter->event_limit);
{
return ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx
&& ctx1->parent_gen == ctx2->parent_gen
- && ctx1->nr_enabled == ctx2->nr_enabled;
+ && !ctx1->pin_count && !ctx2->pin_count;
+}
+
+static void __perf_counter_read(void *counter);
+
+static void __perf_counter_sync_stat(struct perf_counter *counter,
+ struct perf_counter *next_counter)
+{
+ u64 value;
+
+ if (!counter->attr.inherit_stat)
+ return;
+
+ /*
+ * Update the counter value, we cannot use perf_counter_read()
+ * because we're in the middle of a context switch and have IRQs
+ * disabled, which upsets smp_call_function_single(), however
+ * we know the counter must be on the current CPU, therefore we
+ * don't need to use it.
+ */
+ switch (counter->state) {
+ case PERF_COUNTER_STATE_ACTIVE:
+ __perf_counter_read(counter);
+ break;
+
+ case PERF_COUNTER_STATE_INACTIVE:
+ update_counter_times(counter);
+ break;
+
+ default:
+ break;
+ }
+
+ /*
+ * In order to keep per-task stats reliable we need to flip the counter
+ * values when we flip the contexts.
+ */
+ value = atomic64_read(&next_counter->count);
+ value = atomic64_xchg(&counter->count, value);
+ atomic64_set(&next_counter->count, value);
+
+ swap(counter->total_time_enabled, next_counter->total_time_enabled);
+ swap(counter->total_time_running, next_counter->total_time_running);
+
+ /*
+ * Since we swizzled the values, update the user visible data too.
+ */
+ perf_counter_update_userpage(counter);
+ perf_counter_update_userpage(next_counter);
+}
+
+#define list_next_entry(pos, member) \
+ list_entry(pos->member.next, typeof(*pos), member)
+
+static void perf_counter_sync_stat(struct perf_counter_context *ctx,
+ struct perf_counter_context *next_ctx)
+{
+ struct perf_counter *counter, *next_counter;
+
+ if (!ctx->nr_stat)
+ return;
+
+ counter = list_first_entry(&ctx->event_list,
+ struct perf_counter, event_entry);
+
+ next_counter = list_first_entry(&next_ctx->event_list,
+ struct perf_counter, event_entry);
+
+ while (&counter->event_entry != &ctx->event_list &&
+ &next_counter->event_entry != &next_ctx->event_list) {
+
+ __perf_counter_sync_stat(counter, next_counter);
+
+ counter = list_next_entry(counter, event_entry);
+ next_counter = list_next_entry(next_counter, event_entry);
+ }
}
/*
struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu);
struct perf_counter_context *ctx = task->perf_counter_ctxp;
struct perf_counter_context *next_ctx;
+ struct perf_counter_context *parent;
struct pt_regs *regs;
+ int do_switch = 1;
+
+ regs = task_pt_regs(task);
+ perf_swcounter_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, regs, 0);
if (likely(!ctx || !cpuctx->task_ctx))
return;
update_context_time(ctx);
- regs = task_pt_regs(task);
- perf_swcounter_event(PERF_COUNT_CONTEXT_SWITCHES, 1, 1, regs, 0);
-
+ rcu_read_lock();
+ parent = rcu_dereference(ctx->parent_ctx);
next_ctx = next->perf_counter_ctxp;
- if (next_ctx && context_equiv(ctx, next_ctx)) {
- task->perf_counter_ctxp = next_ctx;
- next->perf_counter_ctxp = ctx;
- ctx->task = next;
- next_ctx->task = task;
- return;
- }
+ if (parent && next_ctx &&
+ rcu_dereference(next_ctx->parent_ctx) == parent) {
+ /*
+ * Looks like the two contexts are clones, so we might be
+ * able to optimize the context switch. We lock both
+ * contexts and check that they are clones under the
+ * lock (including re-checking that neither has been
+ * uncloned in the meantime). It doesn't matter which
+ * order we take the locks because no other cpu could
+ * be trying to lock both of these tasks.
+ */
+ spin_lock(&ctx->lock);
+ spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING);
+ if (context_equiv(ctx, next_ctx)) {
+ /*
+ * XXX do we need a memory barrier of sorts
+ * wrt to rcu_dereference() of perf_counter_ctxp
+ */
+ task->perf_counter_ctxp = next_ctx;
+ next->perf_counter_ctxp = ctx;
+ ctx->task = next;
+ next_ctx->task = task;
+ do_switch = 0;
- __perf_counter_sched_out(ctx, cpuctx);
+ perf_counter_sync_stat(ctx, next_ctx);
+ }
+ spin_unlock(&next_ctx->lock);
+ spin_unlock(&ctx->lock);
+ }
+ rcu_read_unlock();
- cpuctx->task_ctx = NULL;
+ if (do_switch) {
+ __perf_counter_sched_out(ctx, cpuctx);
+ cpuctx->task_ctx = NULL;
+ }
}
+/*
+ * Called with IRQs disabled
+ */
static void __perf_counter_task_sched_out(struct perf_counter_context *ctx)
{
struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
if (!cpuctx->task_ctx)
return;
+
+ if (WARN_ON_ONCE(ctx != cpuctx->task_ctx))
+ return;
+
__perf_counter_sched_out(ctx, cpuctx);
cpuctx->task_ctx = NULL;
}
+/*
+ * Called with IRQs disabled
+ */
static void perf_counter_cpu_sched_out(struct perf_cpu_context *cpuctx)
{
__perf_counter_sched_out(&cpuctx->ctx, cpuctx);
*/
list_for_each_entry(counter, &ctx->counter_list, list_entry) {
if (counter->state <= PERF_COUNTER_STATE_OFF ||
- !counter->hw_event.pinned)
+ !counter->attr.pinned)
continue;
if (counter->cpu != -1 && counter->cpu != cpu)
continue;
* ignore pinned counters since we did them already.
*/
if (counter->state <= PERF_COUNTER_STATE_OFF ||
- counter->hw_event.pinned)
+ counter->attr.pinned)
continue;
/*
__perf_counter_sched_in(ctx, cpuctx, cpu);
}
-int perf_counter_task_disable(void)
-{
- struct task_struct *curr = current;
- struct perf_counter_context *ctx = curr->perf_counter_ctxp;
- struct perf_counter *counter;
- unsigned long flags;
-
- if (!ctx || !ctx->nr_counters)
- return 0;
-
- local_irq_save(flags);
+#define MAX_INTERRUPTS (~0ULL)
- __perf_counter_task_sched_out(ctx);
+static void perf_log_throttle(struct perf_counter *counter, int enable);
- spin_lock(&ctx->lock);
+static void perf_adjust_period(struct perf_counter *counter, u64 events)
+{
+ struct hw_perf_counter *hwc = &counter->hw;
+ u64 period, sample_period;
+ s64 delta;
- /*
- * Disable all the counters:
- */
- perf_disable();
+ events *= hwc->sample_period;
+ period = div64_u64(events, counter->attr.sample_freq);
- list_for_each_entry(counter, &ctx->counter_list, list_entry) {
- if (counter->state != PERF_COUNTER_STATE_ERROR) {
- update_group_times(counter);
- counter->state = PERF_COUNTER_STATE_OFF;
- }
- }
+ delta = (s64)(period - hwc->sample_period);
+ delta = (delta + 7) / 8; /* low pass filter */
- perf_enable();
+ sample_period = hwc->sample_period + delta;
- spin_unlock_irqrestore(&ctx->lock, flags);
+ if (!sample_period)
+ sample_period = 1;
- return 0;
+ hwc->sample_period = sample_period;
}
-int perf_counter_task_enable(void)
+static void perf_ctx_adjust_freq(struct perf_counter_context *ctx)
{
- struct task_struct *curr = current;
- struct perf_counter_context *ctx = curr->perf_counter_ctxp;
struct perf_counter *counter;
- unsigned long flags;
- int cpu;
-
- if (!ctx || !ctx->nr_counters)
- return 0;
-
- local_irq_save(flags);
- cpu = smp_processor_id();
-
- __perf_counter_task_sched_out(ctx);
+ struct hw_perf_counter *hwc;
+ u64 interrupts, freq;
spin_lock(&ctx->lock);
-
- /*
- * Disable all the counters:
- */
- perf_disable();
-
list_for_each_entry(counter, &ctx->counter_list, list_entry) {
- if (counter->state > PERF_COUNTER_STATE_OFF)
+ if (counter->state != PERF_COUNTER_STATE_ACTIVE)
continue;
- counter->state = PERF_COUNTER_STATE_INACTIVE;
- counter->tstamp_enabled =
- ctx->time - counter->total_time_enabled;
- counter->hw_event.disabled = 0;
- }
- perf_enable();
-
- spin_unlock(&ctx->lock);
-
- perf_counter_task_sched_in(curr, cpu);
-
- local_irq_restore(flags);
- return 0;
-}
+ hwc = &counter->hw;
-static void perf_log_period(struct perf_counter *counter, u64 period);
-
-static void perf_adjust_freq(struct perf_counter_context *ctx)
-{
- struct perf_counter *counter;
- u64 irq_period;
- u64 events, period;
- s64 delta;
+ interrupts = hwc->interrupts;
+ hwc->interrupts = 0;
- spin_lock(&ctx->lock);
- list_for_each_entry(counter, &ctx->counter_list, list_entry) {
- if (counter->state != PERF_COUNTER_STATE_ACTIVE)
- continue;
+ /*
+ * unthrottle counters on the tick
+ */
+ if (interrupts == MAX_INTERRUPTS) {
+ perf_log_throttle(counter, 1);
+ counter->pmu->unthrottle(counter);
+ interrupts = 2*sysctl_perf_counter_sample_rate/HZ;
+ }
- if (!counter->hw_event.freq || !counter->hw_event.irq_freq)
+ if (!counter->attr.freq || !counter->attr.sample_freq)
continue;
- events = HZ * counter->hw.interrupts * counter->hw.irq_period;
- period = div64_u64(events, counter->hw_event.irq_freq);
+ /*
+ * if the specified freq < HZ then we need to skip ticks
+ */
+ if (counter->attr.sample_freq < HZ) {
+ freq = counter->attr.sample_freq;
- delta = (s64)(1 + period - counter->hw.irq_period);
- delta >>= 1;
+ hwc->freq_count += freq;
+ hwc->freq_interrupts += interrupts;
- irq_period = counter->hw.irq_period + delta;
+ if (hwc->freq_count < HZ)
+ continue;
- if (!irq_period)
- irq_period = 1;
+ interrupts = hwc->freq_interrupts;
+ hwc->freq_interrupts = 0;
+ hwc->freq_count -= HZ;
+ } else
+ freq = HZ;
- perf_log_period(counter, irq_period);
+ perf_adjust_period(counter, freq * interrupts);
- counter->hw.irq_period = irq_period;
- counter->hw.interrupts = 0;
+ /*
+ * In order to avoid being stalled by an (accidental) huge
+ * sample period, force reset the sample period if we didn't
+ * get any events in this freq period.
+ */
+ if (!interrupts) {
+ perf_disable();
+ counter->pmu->disable(counter);
+ atomic64_set(&hwc->period_left, 0);
+ counter->pmu->enable(counter);
+ perf_enable();
+ }
}
spin_unlock(&ctx->lock);
}
cpuctx = &per_cpu(perf_cpu_context, cpu);
ctx = curr->perf_counter_ctxp;
- perf_adjust_freq(&cpuctx->ctx);
+ perf_ctx_adjust_freq(&cpuctx->ctx);
if (ctx)
- perf_adjust_freq(ctx);
+ perf_ctx_adjust_freq(ctx);
perf_counter_cpu_sched_out(cpuctx);
if (ctx)
}
/*
- * Cross CPU call to read the hardware counter
+ * Enable all of a task's counters that have been marked enable-on-exec.
+ * This expects task == current.
*/
-static void __read(void *info)
+static void perf_counter_enable_on_exec(struct task_struct *task)
{
- struct perf_counter *counter = info;
- struct perf_counter_context *ctx = counter->ctx;
+ struct perf_counter_context *ctx;
+ struct perf_counter *counter;
unsigned long flags;
+ int enabled = 0;
local_irq_save(flags);
- if (ctx->is_active)
- update_context_time(ctx);
- counter->pmu->read(counter);
- update_counter_times(counter);
- local_irq_restore(flags);
-}
+ ctx = task->perf_counter_ctxp;
+ if (!ctx || !ctx->nr_counters)
+ goto out;
-static u64 perf_counter_read(struct perf_counter *counter)
-{
- /*
+ __perf_counter_task_sched_out(ctx);
+
+ spin_lock(&ctx->lock);
+
+ list_for_each_entry(counter, &ctx->counter_list, list_entry) {
+ if (!counter->attr.enable_on_exec)
+ continue;
+ counter->attr.enable_on_exec = 0;
+ if (counter->state >= PERF_COUNTER_STATE_INACTIVE)
+ continue;
+ counter->state = PERF_COUNTER_STATE_INACTIVE;
+ counter->tstamp_enabled =
+ ctx->time - counter->total_time_enabled;
+ enabled = 1;
+ }
+
+ /*
+ * Unclone this context if we enabled any counter.
+ */
+ if (enabled)
+ unclone_ctx(ctx);
+
+ spin_unlock(&ctx->lock);
+
+ perf_counter_task_sched_in(task, smp_processor_id());
+ out:
+ local_irq_restore(flags);
+}
+
+/*
+ * Cross CPU call to read the hardware counter
+ */
+static void __perf_counter_read(void *info)
+{
+ struct perf_counter *counter = info;
+ struct perf_counter_context *ctx = counter->ctx;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ if (ctx->is_active)
+ update_context_time(ctx);
+ counter->pmu->read(counter);
+ update_counter_times(counter);
+ local_irq_restore(flags);
+}
+
+static u64 perf_counter_read(struct perf_counter *counter)
+{
+ /*
* If counter is enabled and currently active on a CPU, update the
* value in the counter structure:
*/
if (counter->state == PERF_COUNTER_STATE_ACTIVE) {
smp_call_function_single(counter->oncpu,
- __read, counter, 1);
+ __perf_counter_read, counter, 1);
} else if (counter->state == PERF_COUNTER_STATE_INACTIVE) {
update_counter_times(counter);
}
ctx->task = task;
}
-static void put_context(struct perf_counter_context *ctx)
-{
- if (ctx->task)
- put_task_struct(ctx->task);
-}
-
static struct perf_counter_context *find_get_context(pid_t pid, int cpu)
{
- struct perf_cpu_context *cpuctx;
struct perf_counter_context *ctx;
- struct perf_counter_context *tctx;
+ struct perf_cpu_context *cpuctx;
struct task_struct *task;
+ unsigned long flags;
+ int err;
/*
* If cpu is not a wildcard then this is a percpu counter:
*/
if (cpu != -1) {
/* Must be root to operate on a CPU counter: */
- if (sysctl_perf_counter_priv && !capable(CAP_SYS_ADMIN))
+ if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
return ERR_PTR(-EACCES);
if (cpu < 0 || cpu > num_possible_cpus())
cpuctx = &per_cpu(perf_cpu_context, cpu);
ctx = &cpuctx->ctx;
+ get_ctx(ctx);
return ctx;
}
if (!task)
return ERR_PTR(-ESRCH);
+ /*
+ * Can't attach counters to a dying task.
+ */
+ err = -ESRCH;
+ if (task->flags & PF_EXITING)
+ goto errout;
+
/* Reuse ptrace permission checks for now. */
- if (!ptrace_may_access(task, PTRACE_MODE_READ)) {
- put_task_struct(task);
- return ERR_PTR(-EACCES);
+ err = -EACCES;
+ if (!ptrace_may_access(task, PTRACE_MODE_READ))
+ goto errout;
+
+ retry:
+ ctx = perf_lock_task_context(task, &flags);
+ if (ctx) {
+ unclone_ctx(ctx);
+ spin_unlock_irqrestore(&ctx->lock, flags);
}
- ctx = task->perf_counter_ctxp;
if (!ctx) {
ctx = kmalloc(sizeof(struct perf_counter_context), GFP_KERNEL);
- if (!ctx) {
- put_task_struct(task);
- return ERR_PTR(-ENOMEM);
- }
+ err = -ENOMEM;
+ if (!ctx)
+ goto errout;
__perf_counter_init_context(ctx, task);
- /*
- * Make sure other cpus see correct values for *ctx
- * once task->perf_counter_ctxp is visible to them.
- */
- smp_wmb();
- tctx = cmpxchg(&task->perf_counter_ctxp, NULL, ctx);
- if (tctx) {
+ get_ctx(ctx);
+ if (cmpxchg(&task->perf_counter_ctxp, NULL, ctx)) {
/*
* We raced with some other task; use
* the context they set.
*/
kfree(ctx);
- ctx = tctx;
+ goto retry;
}
+ get_task_struct(task);
}
+ put_task_struct(task);
return ctx;
+
+ errout:
+ put_task_struct(task);
+ return ERR_PTR(err);
}
static void free_counter_rcu(struct rcu_head *head)
struct perf_counter *counter;
counter = container_of(head, struct perf_counter, rcu_head);
- put_ctx(counter->ctx);
+ if (counter->ns)
+ put_pid_ns(counter->ns);
kfree(counter);
}
{
perf_pending_sync(counter);
- atomic_dec(&nr_counters);
- if (counter->hw_event.mmap)
- atomic_dec(&nr_mmap_tracking);
- if (counter->hw_event.munmap)
- atomic_dec(&nr_munmap_tracking);
- if (counter->hw_event.comm)
- atomic_dec(&nr_comm_tracking);
+ if (!counter->parent) {
+ atomic_dec(&nr_counters);
+ if (counter->attr.mmap)
+ atomic_dec(&nr_mmap_counters);
+ if (counter->attr.comm)
+ atomic_dec(&nr_comm_counters);
+ if (counter->attr.task)
+ atomic_dec(&nr_task_counters);
+ }
if (counter->destroy)
counter->destroy(counter);
+ put_ctx(counter->ctx);
call_rcu(&counter->rcu_head, free_counter_rcu);
}
file->private_data = NULL;
+ WARN_ON_ONCE(ctx->parent_ctx);
mutex_lock(&ctx->mutex);
perf_counter_remove_from_context(counter);
mutex_unlock(&ctx->mutex);
+ mutex_lock(&counter->owner->perf_counter_mutex);
+ list_del_init(&counter->owner_entry);
+ mutex_unlock(&counter->owner->perf_counter_mutex);
+ put_task_struct(counter->owner);
+
free_counter(counter);
- put_context(ctx);
return 0;
}
+static int perf_counter_read_size(struct perf_counter *counter)
+{
+ int entry = sizeof(u64); /* value */
+ int size = 0;
+ int nr = 1;
+
+ if (counter->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
+ size += sizeof(u64);
+
+ if (counter->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
+ size += sizeof(u64);
+
+ if (counter->attr.read_format & PERF_FORMAT_ID)
+ entry += sizeof(u64);
+
+ if (counter->attr.read_format & PERF_FORMAT_GROUP) {
+ nr += counter->group_leader->nr_siblings;
+ size += sizeof(u64);
+ }
+
+ size += entry * nr;
+
+ return size;
+}
+
+static u64 perf_counter_read_value(struct perf_counter *counter)
+{
+ struct perf_counter *child;
+ u64 total = 0;
+
+ total += perf_counter_read(counter);
+ list_for_each_entry(child, &counter->child_list, child_list)
+ total += perf_counter_read(child);
+
+ return total;
+}
+
+static int perf_counter_read_entry(struct perf_counter *counter,
+ u64 read_format, char __user *buf)
+{
+ int n = 0, count = 0;
+ u64 values[2];
+
+ values[n++] = perf_counter_read_value(counter);
+ if (read_format & PERF_FORMAT_ID)
+ values[n++] = primary_counter_id(counter);
+
+ count = n * sizeof(u64);
+
+ if (copy_to_user(buf, values, count))
+ return -EFAULT;
+
+ return count;
+}
+
+static int perf_counter_read_group(struct perf_counter *counter,
+ u64 read_format, char __user *buf)
+{
+ struct perf_counter *leader = counter->group_leader, *sub;
+ int n = 0, size = 0, err = -EFAULT;
+ u64 values[3];
+
+ values[n++] = 1 + leader->nr_siblings;
+ if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
+ values[n++] = leader->total_time_enabled +
+ atomic64_read(&leader->child_total_time_enabled);
+ }
+ if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
+ values[n++] = leader->total_time_running +
+ atomic64_read(&leader->child_total_time_running);
+ }
+
+ size = n * sizeof(u64);
+
+ if (copy_to_user(buf, values, size))
+ return -EFAULT;
+
+ err = perf_counter_read_entry(leader, read_format, buf + size);
+ if (err < 0)
+ return err;
+
+ size += err;
+
+ list_for_each_entry(sub, &leader->sibling_list, list_entry) {
+ err = perf_counter_read_entry(counter, read_format,
+ buf + size);
+ if (err < 0)
+ return err;
+
+ size += err;
+ }
+
+ return size;
+}
+
+static int perf_counter_read_one(struct perf_counter *counter,
+ u64 read_format, char __user *buf)
+{
+ u64 values[4];
+ int n = 0;
+
+ values[n++] = perf_counter_read_value(counter);
+ if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
+ values[n++] = counter->total_time_enabled +
+ atomic64_read(&counter->child_total_time_enabled);
+ }
+ if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
+ values[n++] = counter->total_time_running +
+ atomic64_read(&counter->child_total_time_running);
+ }
+ if (read_format & PERF_FORMAT_ID)
+ values[n++] = primary_counter_id(counter);
+
+ if (copy_to_user(buf, values, n * sizeof(u64)))
+ return -EFAULT;
+
+ return n * sizeof(u64);
+}
+
/*
* Read the performance counter - simple non blocking version for now
*/
static ssize_t
perf_read_hw(struct perf_counter *counter, char __user *buf, size_t count)
{
- u64 values[3];
- int n;
+ u64 read_format = counter->attr.read_format;
+ int ret;
/*
* Return end-of-file for a read on a counter that is in
if (counter->state == PERF_COUNTER_STATE_ERROR)
return 0;
+ if (count < perf_counter_read_size(counter))
+ return -ENOSPC;
+
+ WARN_ON_ONCE(counter->ctx->parent_ctx);
mutex_lock(&counter->child_mutex);
- values[0] = perf_counter_read(counter);
- n = 1;
- if (counter->hw_event.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
- values[n++] = counter->total_time_enabled +
- atomic64_read(&counter->child_total_time_enabled);
- if (counter->hw_event.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
- values[n++] = counter->total_time_running +
- atomic64_read(&counter->child_total_time_running);
+ if (read_format & PERF_FORMAT_GROUP)
+ ret = perf_counter_read_group(counter, read_format, buf);
+ else
+ ret = perf_counter_read_one(counter, read_format, buf);
mutex_unlock(&counter->child_mutex);
- if (count < n * sizeof(u64))
- return -EINVAL;
- count = n * sizeof(u64);
-
- if (copy_to_user(buf, values, count))
- return -EFAULT;
-
- return count;
+ return ret;
}
static ssize_t
perf_counter_update_userpage(counter);
}
-static void perf_counter_for_each_sibling(struct perf_counter *counter,
- void (*func)(struct perf_counter *))
-{
- struct perf_counter_context *ctx = counter->ctx;
- struct perf_counter *sibling;
-
- mutex_lock(&ctx->mutex);
- counter = counter->group_leader;
-
- func(counter);
- list_for_each_entry(sibling, &counter->sibling_list, list_entry)
- func(sibling);
- mutex_unlock(&ctx->mutex);
-}
-
+/*
+ * Holding the top-level counter's child_mutex means that any
+ * descendant process that has inherited this counter will block
+ * in sync_child_counter if it goes to exit, thus satisfying the
+ * task existence requirements of perf_counter_enable/disable.
+ */
static void perf_counter_for_each_child(struct perf_counter *counter,
void (*func)(struct perf_counter *))
{
struct perf_counter *child;
+ WARN_ON_ONCE(counter->ctx->parent_ctx);
mutex_lock(&counter->child_mutex);
func(counter);
list_for_each_entry(child, &counter->child_list, child_list)
static void perf_counter_for_each(struct perf_counter *counter,
void (*func)(struct perf_counter *))
{
- struct perf_counter *child;
+ struct perf_counter_context *ctx = counter->ctx;
+ struct perf_counter *sibling;
- mutex_lock(&counter->child_mutex);
- perf_counter_for_each_sibling(counter, func);
- list_for_each_entry(child, &counter->child_list, child_list)
- perf_counter_for_each_sibling(child, func);
- mutex_unlock(&counter->child_mutex);
+ WARN_ON_ONCE(ctx->parent_ctx);
+ mutex_lock(&ctx->mutex);
+ counter = counter->group_leader;
+
+ perf_counter_for_each_child(counter, func);
+ func(counter);
+ list_for_each_entry(sibling, &counter->sibling_list, list_entry)
+ perf_counter_for_each_child(counter, func);
+ mutex_unlock(&ctx->mutex);
+}
+
+static int perf_counter_period(struct perf_counter *counter, u64 __user *arg)
+{
+ struct perf_counter_context *ctx = counter->ctx;
+ unsigned long size;
+ int ret = 0;
+ u64 value;
+
+ if (!counter->attr.sample_period)
+ return -EINVAL;
+
+ size = copy_from_user(&value, arg, sizeof(value));
+ if (size != sizeof(value))
+ return -EFAULT;
+
+ if (!value)
+ return -EINVAL;
+
+ spin_lock_irq(&ctx->lock);
+ if (counter->attr.freq) {
+ if (value > sysctl_perf_counter_sample_rate) {
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ counter->attr.sample_freq = value;
+ } else {
+ counter->attr.sample_period = value;
+ counter->hw.sample_period = value;
+ }
+unlock:
+ spin_unlock_irq(&ctx->lock);
+
+ return ret;
}
static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case PERF_COUNTER_IOC_REFRESH:
return perf_counter_refresh(counter, arg);
+
+ case PERF_COUNTER_IOC_PERIOD:
+ return perf_counter_period(counter, (u64 __user *)arg);
+
default:
return -ENOTTY;
}
return 0;
}
+int perf_counter_task_enable(void)
+{
+ struct perf_counter *counter;
+
+ mutex_lock(¤t->perf_counter_mutex);
+ list_for_each_entry(counter, ¤t->perf_counter_list, owner_entry)
+ perf_counter_for_each_child(counter, perf_counter_enable);
+ mutex_unlock(¤t->perf_counter_mutex);
+
+ return 0;
+}
+
+int perf_counter_task_disable(void)
+{
+ struct perf_counter *counter;
+
+ mutex_lock(¤t->perf_counter_mutex);
+ list_for_each_entry(counter, ¤t->perf_counter_list, owner_entry)
+ perf_counter_for_each_child(counter, perf_counter_disable);
+ mutex_unlock(¤t->perf_counter_mutex);
+
+ return 0;
+}
+
+static int perf_counter_index(struct perf_counter *counter)
+{
+ if (counter->state != PERF_COUNTER_STATE_ACTIVE)
+ return 0;
+
+ return counter->hw.idx + 1 - PERF_COUNTER_INDEX_OFFSET;
+}
+
/*
* Callers need to ensure there can be no nesting of this function, otherwise
* the seqlock logic goes bad. We can not serialize this because the arch
*/
void perf_counter_update_userpage(struct perf_counter *counter)
{
- struct perf_mmap_data *data;
struct perf_counter_mmap_page *userpg;
+ struct perf_mmap_data *data;
rcu_read_lock();
data = rcu_dereference(counter->data);
preempt_disable();
++userpg->lock;
barrier();
- userpg->index = counter->hw.idx;
+ userpg->index = perf_counter_index(counter);
userpg->offset = atomic64_read(&counter->count);
if (counter->state == PERF_COUNTER_STATE_ACTIVE)
userpg->offset -= atomic64_read(&counter->hw.prev_count);
+ userpg->time_enabled = counter->total_time_enabled +
+ atomic64_read(&counter->child_total_time_enabled);
+
+ userpg->time_running = counter->total_time_running +
+ atomic64_read(&counter->child_total_time_running);
+
barrier();
++userpg->lock;
preempt_enable();
struct perf_mmap_data *data;
int ret = VM_FAULT_SIGBUS;
+ if (vmf->flags & FAULT_FLAG_MKWRITE) {
+ if (vmf->pgoff == 0)
+ ret = 0;
+ return ret;
+ }
+
rcu_read_lock();
data = rcu_dereference(counter->data);
if (!data)
if ((unsigned)nr > data->nr_pages)
goto unlock;
+ if (vmf->flags & FAULT_FLAG_WRITE)
+ goto unlock;
+
vmf->page = virt_to_page(data->data_pages[nr]);
}
+
get_page(vmf->page);
+ vmf->page->mapping = vma->vm_file->f_mapping;
+ vmf->page->index = vmf->pgoff;
+
ret = 0;
unlock:
rcu_read_unlock();
return -ENOMEM;
}
+static void perf_mmap_free_page(unsigned long addr)
+{
+ struct page *page = virt_to_page((void *)addr);
+
+ page->mapping = NULL;
+ __free_page(page);
+}
+
static void __perf_mmap_data_free(struct rcu_head *rcu_head)
{
- struct perf_mmap_data *data = container_of(rcu_head,
- struct perf_mmap_data, rcu_head);
+ struct perf_mmap_data *data;
int i;
- free_page((unsigned long)data->user_page);
+ data = container_of(rcu_head, struct perf_mmap_data, rcu_head);
+
+ perf_mmap_free_page((unsigned long)data->user_page);
for (i = 0; i < data->nr_pages; i++)
- free_page((unsigned long)data->data_pages[i]);
+ perf_mmap_free_page((unsigned long)data->data_pages[i]);
+
kfree(data);
}
{
struct perf_counter *counter = vma->vm_file->private_data;
- if (atomic_dec_and_mutex_lock(&counter->mmap_count,
- &counter->mmap_mutex)) {
+ WARN_ON_ONCE(counter->ctx->parent_ctx);
+ if (atomic_dec_and_mutex_lock(&counter->mmap_count, &counter->mmap_mutex)) {
struct user_struct *user = current_user();
atomic_long_sub(counter->data->nr_pages + 1, &user->locked_vm);
}
static struct vm_operations_struct perf_mmap_vmops = {
- .open = perf_mmap_open,
- .close = perf_mmap_close,
- .fault = perf_mmap_fault,
+ .open = perf_mmap_open,
+ .close = perf_mmap_close,
+ .fault = perf_mmap_fault,
+ .page_mkwrite = perf_mmap_fault,
};
static int perf_mmap(struct file *file, struct vm_area_struct *vma)
{
struct perf_counter *counter = file->private_data;
+ unsigned long user_locked, user_lock_limit;
struct user_struct *user = current_user();
+ unsigned long locked, lock_limit;
unsigned long vma_size;
unsigned long nr_pages;
- unsigned long user_locked, user_lock_limit;
- unsigned long locked, lock_limit;
long user_extra, extra;
int ret = 0;
- if (!(vma->vm_flags & VM_SHARED) || (vma->vm_flags & VM_WRITE))
+ if (!(vma->vm_flags & VM_SHARED))
return -EINVAL;
vma_size = vma->vm_end - vma->vm_start;
if (vma->vm_pgoff != 0)
return -EINVAL;
+ WARN_ON_ONCE(counter->ctx->parent_ctx);
mutex_lock(&counter->mmap_mutex);
if (atomic_inc_not_zero(&counter->mmap_count)) {
if (nr_pages != counter->data->nr_pages)
user_extra = nr_pages + 1;
user_lock_limit = sysctl_perf_counter_mlock >> (PAGE_SHIFT - 10);
+
+ /*
+ * Increase the limit linearly with more CPUs:
+ */
+ user_lock_limit *= num_online_cpus();
+
user_locked = atomic_long_read(&user->locked_vm) + user_extra;
extra = 0;
atomic_long_add(user_extra, &user->locked_vm);
vma->vm_mm->locked_vm += extra;
counter->data->nr_locked = extra;
+ if (vma->vm_flags & VM_WRITE)
+ counter->data->writable = 1;
+
unlock:
mutex_unlock(&counter->mmap_mutex);
- vma->vm_flags &= ~VM_MAYWRITE;
vma->vm_flags |= VM_RESERVED;
vma->vm_ops = &perf_mmap_vmops;
static int perf_fasync(int fd, struct file *filp, int on)
{
- struct perf_counter *counter = filp->private_data;
struct inode *inode = filp->f_path.dentry->d_inode;
+ struct perf_counter *counter = filp->private_data;
int retval;
mutex_lock(&inode->i_mutex);
if (counter->pending_disable) {
counter->pending_disable = 0;
- perf_counter_disable(counter);
+ __perf_counter_disable(counter);
}
if (counter->pending_wakeup) {
struct perf_output_handle {
struct perf_counter *counter;
struct perf_mmap_data *data;
- unsigned int offset;
- unsigned int head;
+ unsigned long head;
+ unsigned long offset;
int nmi;
- int overflow;
+ int sample;
int locked;
unsigned long flags;
};
+static bool perf_output_space(struct perf_mmap_data *data,
+ unsigned int offset, unsigned int head)
+{
+ unsigned long tail;
+ unsigned long mask;
+
+ if (!data->writable)
+ return true;
+
+ mask = (data->nr_pages << PAGE_SHIFT) - 1;
+ /*
+ * Userspace could choose to issue a mb() before updating the tail
+ * pointer. So that all reads will be completed before the write is
+ * issued.
+ */
+ tail = ACCESS_ONCE(data->user_page->data_tail);
+ smp_rmb();
+
+ offset = (offset - tail) & mask;
+ head = (head - tail) & mask;
+
+ if ((int)(head - offset) < 0)
+ return false;
+
+ return true;
+}
+
static void perf_output_wakeup(struct perf_output_handle *handle)
{
atomic_set(&handle->data->poll, POLL_IN);
static void perf_output_unlock(struct perf_output_handle *handle)
{
struct perf_mmap_data *data = handle->data;
- int head, cpu;
+ unsigned long head;
+ int cpu;
data->done_head = data->head;
* before we publish the new head, matched by a rmb() in userspace when
* reading this position.
*/
- while ((head = atomic_xchg(&data->done_head, 0)))
+ while ((head = atomic_long_xchg(&data->done_head, 0)))
data->user_page->data_head = head;
/*
/*
* Therefore we have to validate we did not indeed do so.
*/
- if (unlikely(atomic_read(&data->done_head))) {
+ if (unlikely(atomic_long_read(&data->done_head))) {
/*
* Since we had it locked, we can lock it again.
*/
local_irq_restore(handle->flags);
}
+static void perf_output_copy(struct perf_output_handle *handle,
+ const void *buf, unsigned int len)
+{
+ unsigned int pages_mask;
+ unsigned int offset;
+ unsigned int size;
+ void **pages;
+
+ offset = handle->offset;
+ pages_mask = handle->data->nr_pages - 1;
+ pages = handle->data->data_pages;
+
+ do {
+ unsigned int page_offset;
+ int nr;
+
+ nr = (offset >> PAGE_SHIFT) & pages_mask;
+ page_offset = offset & (PAGE_SIZE - 1);
+ size = min_t(unsigned int, PAGE_SIZE - page_offset, len);
+
+ memcpy(pages[nr] + page_offset, buf, size);
+
+ len -= size;
+ buf += size;
+ offset += size;
+ } while (len);
+
+ handle->offset = offset;
+
+ /*
+ * Check we didn't copy past our reservation window, taking the
+ * possible unsigned int wrap into account.
+ */
+ WARN_ON_ONCE(((long)(handle->head - handle->offset)) < 0);
+}
+
+#define perf_output_put(handle, x) \
+ perf_output_copy((handle), &(x), sizeof(x))
+
static int perf_output_begin(struct perf_output_handle *handle,
struct perf_counter *counter, unsigned int size,
- int nmi, int overflow)
+ int nmi, int sample)
{
struct perf_mmap_data *data;
unsigned int offset, head;
+ int have_lost;
+ struct {
+ struct perf_event_header header;
+ u64 id;
+ u64 lost;
+ } lost_event;
/*
* For inherited counters we send all the output towards the parent.
if (!data)
goto out;
- handle->data = data;
- handle->counter = counter;
- handle->nmi = nmi;
- handle->overflow = overflow;
+ handle->data = data;
+ handle->counter = counter;
+ handle->nmi = nmi;
+ handle->sample = sample;
if (!data->nr_pages)
goto fail;
+ have_lost = atomic_read(&data->lost);
+ if (have_lost)
+ size += sizeof(lost_event);
+
perf_output_lock(handle);
do {
- offset = head = atomic_read(&data->head);
+ offset = head = atomic_long_read(&data->head);
head += size;
- } while (atomic_cmpxchg(&data->head, offset, head) != offset);
+ if (unlikely(!perf_output_space(data, offset, head)))
+ goto fail;
+ } while (atomic_long_cmpxchg(&data->head, offset, head) != offset);
handle->offset = offset;
handle->head = head;
if ((offset >> PAGE_SHIFT) != (head >> PAGE_SHIFT))
atomic_set(&data->wakeup, 1);
+ if (have_lost) {
+ lost_event.header.type = PERF_EVENT_LOST;
+ lost_event.header.misc = 0;
+ lost_event.header.size = sizeof(lost_event);
+ lost_event.id = counter->id;
+ lost_event.lost = atomic_xchg(&data->lost, 0);
+
+ perf_output_put(handle, lost_event);
+ }
+
return 0;
fail:
- perf_output_wakeup(handle);
+ atomic_inc(&data->lost);
+ perf_output_unlock(handle);
out:
rcu_read_unlock();
return -ENOSPC;
}
-static void perf_output_copy(struct perf_output_handle *handle,
- void *buf, unsigned int len)
+static void perf_output_end(struct perf_output_handle *handle)
{
- unsigned int pages_mask;
- unsigned int offset;
- unsigned int size;
- void **pages;
-
- offset = handle->offset;
- pages_mask = handle->data->nr_pages - 1;
- pages = handle->data->data_pages;
+ struct perf_counter *counter = handle->counter;
+ struct perf_mmap_data *data = handle->data;
- do {
- unsigned int page_offset;
- int nr;
+ int wakeup_events = counter->attr.wakeup_events;
- nr = (offset >> PAGE_SHIFT) & pages_mask;
- page_offset = offset & (PAGE_SIZE - 1);
- size = min_t(unsigned int, PAGE_SIZE - page_offset, len);
+ if (handle->sample && wakeup_events) {
+ int events = atomic_inc_return(&data->events);
+ if (events >= wakeup_events) {
+ atomic_sub(wakeup_events, &data->events);
+ atomic_set(&data->wakeup, 1);
+ }
+ }
- memcpy(pages[nr] + page_offset, buf, size);
+ perf_output_unlock(handle);
+ rcu_read_unlock();
+}
- len -= size;
- buf += size;
- offset += size;
- } while (len);
+static u32 perf_counter_pid(struct perf_counter *counter, struct task_struct *p)
+{
+ /*
+ * only top level counters have the pid namespace they were created in
+ */
+ if (counter->parent)
+ counter = counter->parent;
- handle->offset = offset;
+ return task_tgid_nr_ns(p, counter->ns);
+}
+static u32 perf_counter_tid(struct perf_counter *counter, struct task_struct *p)
+{
/*
- * Check we didn't copy past our reservation window, taking the
- * possible unsigned int wrap into account.
+ * only top level counters have the pid namespace they were created in
*/
- WARN_ON_ONCE(((int)(handle->head - handle->offset)) < 0);
+ if (counter->parent)
+ counter = counter->parent;
+
+ return task_pid_nr_ns(p, counter->ns);
}
-#define perf_output_put(handle, x) \
- perf_output_copy((handle), &(x), sizeof(x))
+static void perf_output_read_one(struct perf_output_handle *handle,
+ struct perf_counter *counter)
+{
+ u64 read_format = counter->attr.read_format;
+ u64 values[4];
+ int n = 0;
-static void perf_output_end(struct perf_output_handle *handle)
+ values[n++] = atomic64_read(&counter->count);
+ if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
+ values[n++] = counter->total_time_enabled +
+ atomic64_read(&counter->child_total_time_enabled);
+ }
+ if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
+ values[n++] = counter->total_time_running +
+ atomic64_read(&counter->child_total_time_running);
+ }
+ if (read_format & PERF_FORMAT_ID)
+ values[n++] = primary_counter_id(counter);
+
+ perf_output_copy(handle, values, n * sizeof(u64));
+}
+
+/*
+ * XXX PERF_FORMAT_GROUP vs inherited counters seems difficult.
+ */
+static void perf_output_read_group(struct perf_output_handle *handle,
+ struct perf_counter *counter)
{
- struct perf_counter *counter = handle->counter;
- struct perf_mmap_data *data = handle->data;
+ struct perf_counter *leader = counter->group_leader, *sub;
+ u64 read_format = counter->attr.read_format;
+ u64 values[5];
+ int n = 0;
- int wakeup_events = counter->hw_event.wakeup_events;
+ values[n++] = 1 + leader->nr_siblings;
- if (handle->overflow && wakeup_events) {
- int events = atomic_inc_return(&data->events);
- if (events >= wakeup_events) {
- atomic_sub(wakeup_events, &data->events);
- atomic_set(&data->wakeup, 1);
- }
+ if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
+ values[n++] = leader->total_time_enabled;
+
+ if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
+ values[n++] = leader->total_time_running;
+
+ if (leader != counter)
+ leader->pmu->read(leader);
+
+ values[n++] = atomic64_read(&leader->count);
+ if (read_format & PERF_FORMAT_ID)
+ values[n++] = primary_counter_id(leader);
+
+ perf_output_copy(handle, values, n * sizeof(u64));
+
+ list_for_each_entry(sub, &leader->sibling_list, list_entry) {
+ n = 0;
+
+ if (sub != counter)
+ sub->pmu->read(sub);
+
+ values[n++] = atomic64_read(&sub->count);
+ if (read_format & PERF_FORMAT_ID)
+ values[n++] = primary_counter_id(sub);
+
+ perf_output_copy(handle, values, n * sizeof(u64));
}
+}
- perf_output_unlock(handle);
- rcu_read_unlock();
+static void perf_output_read(struct perf_output_handle *handle,
+ struct perf_counter *counter)
+{
+ if (counter->attr.read_format & PERF_FORMAT_GROUP)
+ perf_output_read_group(handle, counter);
+ else
+ perf_output_read_one(handle, counter);
}
-static void perf_counter_output(struct perf_counter *counter,
- int nmi, struct pt_regs *regs, u64 addr)
+void perf_counter_output(struct perf_counter *counter, int nmi,
+ struct perf_sample_data *data)
{
int ret;
- u64 record_type = counter->hw_event.record_type;
+ u64 sample_type = counter->attr.sample_type;
struct perf_output_handle handle;
struct perf_event_header header;
u64 ip;
struct {
u32 pid, tid;
} tid_entry;
- struct {
- u64 event;
- u64 counter;
- } group_entry;
struct perf_callchain_entry *callchain = NULL;
int callchain_size = 0;
u64 time;
u32 cpu, reserved;
} cpu_entry;
- header.type = 0;
+ header.type = PERF_EVENT_SAMPLE;
header.size = sizeof(header);
- header.misc = PERF_EVENT_MISC_OVERFLOW;
- header.misc |= perf_misc_flags(regs);
+ header.misc = 0;
+ header.misc |= perf_misc_flags(data->regs);
- if (record_type & PERF_RECORD_IP) {
- ip = perf_instruction_pointer(regs);
- header.type |= PERF_RECORD_IP;
+ if (sample_type & PERF_SAMPLE_IP) {
+ ip = perf_instruction_pointer(data->regs);
header.size += sizeof(ip);
}
- if (record_type & PERF_RECORD_TID) {
+ if (sample_type & PERF_SAMPLE_TID) {
/* namespace issues */
- tid_entry.pid = current->group_leader->pid;
- tid_entry.tid = current->pid;
+ tid_entry.pid = perf_counter_pid(counter, current);
+ tid_entry.tid = perf_counter_tid(counter, current);
- header.type |= PERF_RECORD_TID;
header.size += sizeof(tid_entry);
}
- if (record_type & PERF_RECORD_TIME) {
+ if (sample_type & PERF_SAMPLE_TIME) {
/*
* Maybe do better on x86 and provide cpu_clock_nmi()
*/
time = sched_clock();
- header.type |= PERF_RECORD_TIME;
header.size += sizeof(u64);
}
- if (record_type & PERF_RECORD_ADDR) {
- header.type |= PERF_RECORD_ADDR;
+ if (sample_type & PERF_SAMPLE_ADDR)
header.size += sizeof(u64);
- }
- if (record_type & PERF_RECORD_CONFIG) {
- header.type |= PERF_RECORD_CONFIG;
+ if (sample_type & PERF_SAMPLE_ID)
+ header.size += sizeof(u64);
+
+ if (sample_type & PERF_SAMPLE_STREAM_ID)
header.size += sizeof(u64);
- }
- if (record_type & PERF_RECORD_CPU) {
- header.type |= PERF_RECORD_CPU;
+ if (sample_type & PERF_SAMPLE_CPU) {
header.size += sizeof(cpu_entry);
cpu_entry.cpu = raw_smp_processor_id();
+ cpu_entry.reserved = 0;
}
- if (record_type & PERF_RECORD_GROUP) {
- header.type |= PERF_RECORD_GROUP;
- header.size += sizeof(u64) +
- counter->nr_siblings * sizeof(group_entry);
- }
+ if (sample_type & PERF_SAMPLE_PERIOD)
+ header.size += sizeof(u64);
- if (record_type & PERF_RECORD_CALLCHAIN) {
- callchain = perf_callchain(regs);
+ if (sample_type & PERF_SAMPLE_READ)
+ header.size += perf_counter_read_size(counter);
+
+ if (sample_type & PERF_SAMPLE_CALLCHAIN) {
+ callchain = perf_callchain(data->regs);
if (callchain) {
callchain_size = (1 + callchain->nr) * sizeof(u64);
-
- header.type |= PERF_RECORD_CALLCHAIN;
header.size += callchain_size;
- }
+ } else
+ header.size += sizeof(u64);
+ }
+
+ if (sample_type & PERF_SAMPLE_RAW) {
+ int size = sizeof(u32);
+
+ if (data->raw)
+ size += data->raw->size;
+ else
+ size += sizeof(u32);
+
+ WARN_ON_ONCE(size & (sizeof(u64)-1));
+ header.size += size;
}
ret = perf_output_begin(&handle, counter, header.size, nmi, 1);
perf_output_put(&handle, header);
- if (record_type & PERF_RECORD_IP)
+ if (sample_type & PERF_SAMPLE_IP)
perf_output_put(&handle, ip);
- if (record_type & PERF_RECORD_TID)
+ if (sample_type & PERF_SAMPLE_TID)
perf_output_put(&handle, tid_entry);
- if (record_type & PERF_RECORD_TIME)
+ if (sample_type & PERF_SAMPLE_TIME)
perf_output_put(&handle, time);
- if (record_type & PERF_RECORD_ADDR)
- perf_output_put(&handle, addr);
+ if (sample_type & PERF_SAMPLE_ADDR)
+ perf_output_put(&handle, data->addr);
- if (record_type & PERF_RECORD_CONFIG)
- perf_output_put(&handle, counter->hw_event.config);
+ if (sample_type & PERF_SAMPLE_ID) {
+ u64 id = primary_counter_id(counter);
- if (record_type & PERF_RECORD_CPU)
- perf_output_put(&handle, cpu_entry);
+ perf_output_put(&handle, id);
+ }
- /*
- * XXX PERF_RECORD_GROUP vs inherited counters seems difficult.
- */
- if (record_type & PERF_RECORD_GROUP) {
- struct perf_counter *leader, *sub;
- u64 nr = counter->nr_siblings;
+ if (sample_type & PERF_SAMPLE_STREAM_ID)
+ perf_output_put(&handle, counter->id);
+
+ if (sample_type & PERF_SAMPLE_CPU)
+ perf_output_put(&handle, cpu_entry);
- perf_output_put(&handle, nr);
+ if (sample_type & PERF_SAMPLE_PERIOD)
+ perf_output_put(&handle, data->period);
- leader = counter->group_leader;
- list_for_each_entry(sub, &leader->sibling_list, list_entry) {
- if (sub != counter)
- sub->pmu->read(sub);
+ if (sample_type & PERF_SAMPLE_READ)
+ perf_output_read(&handle, counter);
- group_entry.event = sub->hw_event.config;
- group_entry.counter = atomic64_read(&sub->count);
+ if (sample_type & PERF_SAMPLE_CALLCHAIN) {
+ if (callchain)
+ perf_output_copy(&handle, callchain, callchain_size);
+ else {
+ u64 nr = 0;
+ perf_output_put(&handle, nr);
+ }
+ }
- perf_output_put(&handle, group_entry);
+ if (sample_type & PERF_SAMPLE_RAW) {
+ if (data->raw) {
+ perf_output_put(&handle, data->raw->size);
+ perf_output_copy(&handle, data->raw->data, data->raw->size);
+ } else {
+ struct {
+ u32 size;
+ u32 data;
+ } raw = {
+ .size = sizeof(u32),
+ .data = 0,
+ };
+ perf_output_put(&handle, raw);
}
}
- if (callchain)
- perf_output_copy(&handle, callchain, callchain_size);
+ perf_output_end(&handle);
+}
+
+/*
+ * read event
+ */
+
+struct perf_read_event {
+ struct perf_event_header header;
+
+ u32 pid;
+ u32 tid;
+};
+
+static void
+perf_counter_read_event(struct perf_counter *counter,
+ struct task_struct *task)
+{
+ struct perf_output_handle handle;
+ struct perf_read_event event = {
+ .header = {
+ .type = PERF_EVENT_READ,
+ .misc = 0,
+ .size = sizeof(event) + perf_counter_read_size(counter),
+ },
+ .pid = perf_counter_pid(counter, task),
+ .tid = perf_counter_tid(counter, task),
+ };
+ int ret;
+
+ ret = perf_output_begin(&handle, counter, event.header.size, 0, 0);
+ if (ret)
+ return;
+
+ perf_output_put(&handle, event);
+ perf_output_read(&handle, counter);
+
+ perf_output_end(&handle);
+}
+
+/*
+ * task tracking -- fork/exit
+ *
+ * enabled by: attr.comm | attr.mmap | attr.task
+ */
+
+struct perf_task_event {
+ struct task_struct *task;
+ struct perf_counter_context *task_ctx;
+
+ struct {
+ struct perf_event_header header;
+
+ u32 pid;
+ u32 ppid;
+ u32 tid;
+ u32 ptid;
+ } event;
+};
+
+static void perf_counter_task_output(struct perf_counter *counter,
+ struct perf_task_event *task_event)
+{
+ struct perf_output_handle handle;
+ int size = task_event->event.header.size;
+ struct task_struct *task = task_event->task;
+ int ret = perf_output_begin(&handle, counter, size, 0, 0);
+
+ if (ret)
+ return;
+
+ task_event->event.pid = perf_counter_pid(counter, task);
+ task_event->event.ppid = perf_counter_pid(counter, current);
+
+ task_event->event.tid = perf_counter_tid(counter, task);
+ task_event->event.ptid = perf_counter_tid(counter, current);
+ perf_output_put(&handle, task_event->event);
perf_output_end(&handle);
}
+static int perf_counter_task_match(struct perf_counter *counter)
+{
+ if (counter->attr.comm || counter->attr.mmap || counter->attr.task)
+ return 1;
+
+ return 0;
+}
+
+static void perf_counter_task_ctx(struct perf_counter_context *ctx,
+ struct perf_task_event *task_event)
+{
+ struct perf_counter *counter;
+
+ if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list))
+ return;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) {
+ if (perf_counter_task_match(counter))
+ perf_counter_task_output(counter, task_event);
+ }
+ rcu_read_unlock();
+}
+
+static void perf_counter_task_event(struct perf_task_event *task_event)
+{
+ struct perf_cpu_context *cpuctx;
+ struct perf_counter_context *ctx = task_event->task_ctx;
+
+ cpuctx = &get_cpu_var(perf_cpu_context);
+ perf_counter_task_ctx(&cpuctx->ctx, task_event);
+ put_cpu_var(perf_cpu_context);
+
+ rcu_read_lock();
+ if (!ctx)
+ ctx = rcu_dereference(task_event->task->perf_counter_ctxp);
+ if (ctx)
+ perf_counter_task_ctx(ctx, task_event);
+ rcu_read_unlock();
+}
+
+static void perf_counter_task(struct task_struct *task,
+ struct perf_counter_context *task_ctx,
+ int new)
+{
+ struct perf_task_event task_event;
+
+ if (!atomic_read(&nr_comm_counters) &&
+ !atomic_read(&nr_mmap_counters) &&
+ !atomic_read(&nr_task_counters))
+ return;
+
+ task_event = (struct perf_task_event){
+ .task = task,
+ .task_ctx = task_ctx,
+ .event = {
+ .header = {
+ .type = new ? PERF_EVENT_FORK : PERF_EVENT_EXIT,
+ .misc = 0,
+ .size = sizeof(task_event.event),
+ },
+ /* .pid */
+ /* .ppid */
+ /* .tid */
+ /* .ptid */
+ },
+ };
+
+ perf_counter_task_event(&task_event);
+}
+
+void perf_counter_fork(struct task_struct *task)
+{
+ perf_counter_task(task, NULL, 1);
+}
+
/*
* comm tracking
*/
struct perf_comm_event {
- struct task_struct *task;
- char *comm;
+ struct task_struct *task;
+ char *comm;
int comm_size;
struct {
if (ret)
return;
+ comm_event->event.pid = perf_counter_pid(counter, comm_event->task);
+ comm_event->event.tid = perf_counter_tid(counter, comm_event->task);
+
perf_output_put(&handle, comm_event->event);
perf_output_copy(&handle, comm_event->comm,
comm_event->comm_size);
perf_output_end(&handle);
}
-static int perf_counter_comm_match(struct perf_counter *counter,
- struct perf_comm_event *comm_event)
+static int perf_counter_comm_match(struct perf_counter *counter)
{
- if (counter->hw_event.comm &&
- comm_event->event.header.type == PERF_EVENT_COMM)
+ if (counter->attr.comm)
return 1;
return 0;
rcu_read_lock();
list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) {
- if (perf_counter_comm_match(counter, comm_event))
+ if (perf_counter_comm_match(counter))
perf_counter_comm_output(counter, comm_event);
}
rcu_read_unlock();
static void perf_counter_comm_event(struct perf_comm_event *comm_event)
{
struct perf_cpu_context *cpuctx;
+ struct perf_counter_context *ctx;
unsigned int size;
- char *comm = comm_event->task->comm;
+ char comm[TASK_COMM_LEN];
+ memset(comm, 0, sizeof(comm));
+ strncpy(comm, comm_event->task->comm, sizeof(comm));
size = ALIGN(strlen(comm)+1, sizeof(u64));
comm_event->comm = comm;
perf_counter_comm_ctx(&cpuctx->ctx, comm_event);
put_cpu_var(perf_cpu_context);
- perf_counter_comm_ctx(current->perf_counter_ctxp, comm_event);
+ rcu_read_lock();
+ /*
+ * doesn't really matter which of the child contexts the
+ * events ends up in.
+ */
+ ctx = rcu_dereference(current->perf_counter_ctxp);
+ if (ctx)
+ perf_counter_comm_ctx(ctx, comm_event);
+ rcu_read_unlock();
}
void perf_counter_comm(struct task_struct *task)
{
struct perf_comm_event comm_event;
- if (!atomic_read(&nr_comm_tracking))
- return;
- if (!current->perf_counter_ctxp)
+ if (task->perf_counter_ctxp)
+ perf_counter_enable_on_exec(task);
+
+ if (!atomic_read(&nr_comm_counters))
return;
comm_event = (struct perf_comm_event){
.task = task,
+ /* .comm */
+ /* .comm_size */
.event = {
- .header = { .type = PERF_EVENT_COMM, },
- .pid = task->group_leader->pid,
- .tid = task->pid,
+ .header = {
+ .type = PERF_EVENT_COMM,
+ .misc = 0,
+ /* .size */
+ },
+ /* .pid */
+ /* .tid */
},
};
*/
struct perf_mmap_event {
- struct file *file;
- char *file_name;
- int file_size;
+ struct vm_area_struct *vma;
+
+ const char *file_name;
+ int file_size;
struct {
struct perf_event_header header;
if (ret)
return;
+ mmap_event->event.pid = perf_counter_pid(counter, current);
+ mmap_event->event.tid = perf_counter_tid(counter, current);
+
perf_output_put(&handle, mmap_event->event);
perf_output_copy(&handle, mmap_event->file_name,
mmap_event->file_size);
static int perf_counter_mmap_match(struct perf_counter *counter,
struct perf_mmap_event *mmap_event)
{
- if (counter->hw_event.mmap &&
- mmap_event->event.header.type == PERF_EVENT_MMAP)
- return 1;
-
- if (counter->hw_event.munmap &&
- mmap_event->event.header.type == PERF_EVENT_MUNMAP)
+ if (counter->attr.mmap)
return 1;
return 0;
static void perf_counter_mmap_event(struct perf_mmap_event *mmap_event)
{
struct perf_cpu_context *cpuctx;
- struct file *file = mmap_event->file;
+ struct perf_counter_context *ctx;
+ struct vm_area_struct *vma = mmap_event->vma;
+ struct file *file = vma->vm_file;
unsigned int size;
char tmp[16];
char *buf = NULL;
- char *name;
+ const char *name;
+
+ memset(tmp, 0, sizeof(tmp));
if (file) {
- buf = kzalloc(PATH_MAX, GFP_KERNEL);
+ /*
+ * d_path works from the end of the buffer backwards, so we
+ * need to add enough zero bytes after the string to handle
+ * the 64bit alignment we do later.
+ */
+ buf = kzalloc(PATH_MAX + sizeof(u64), GFP_KERNEL);
if (!buf) {
name = strncpy(tmp, "//enomem", sizeof(tmp));
goto got_name;
goto got_name;
}
} else {
+ if (arch_vma_name(mmap_event->vma)) {
+ name = strncpy(tmp, arch_vma_name(mmap_event->vma),
+ sizeof(tmp));
+ goto got_name;
+ }
+
+ if (!vma->vm_mm) {
+ name = strncpy(tmp, "[vdso]", sizeof(tmp));
+ goto got_name;
+ }
+
name = strncpy(tmp, "//anon", sizeof(tmp));
goto got_name;
}
perf_counter_mmap_ctx(&cpuctx->ctx, mmap_event);
put_cpu_var(perf_cpu_context);
- perf_counter_mmap_ctx(current->perf_counter_ctxp, mmap_event);
+ rcu_read_lock();
+ /*
+ * doesn't really matter which of the child contexts the
+ * events ends up in.
+ */
+ ctx = rcu_dereference(current->perf_counter_ctxp);
+ if (ctx)
+ perf_counter_mmap_ctx(ctx, mmap_event);
+ rcu_read_unlock();
kfree(buf);
}
-void perf_counter_mmap(unsigned long addr, unsigned long len,
- unsigned long pgoff, struct file *file)
-{
- struct perf_mmap_event mmap_event;
-
- if (!atomic_read(&nr_mmap_tracking))
- return;
- if (!current->perf_counter_ctxp)
- return;
-
- mmap_event = (struct perf_mmap_event){
- .file = file,
- .event = {
- .header = { .type = PERF_EVENT_MMAP, },
- .pid = current->group_leader->pid,
- .tid = current->pid,
- .start = addr,
- .len = len,
- .pgoff = pgoff,
- },
- };
-
- perf_counter_mmap_event(&mmap_event);
-}
-
-void perf_counter_munmap(unsigned long addr, unsigned long len,
- unsigned long pgoff, struct file *file)
+void __perf_counter_mmap(struct vm_area_struct *vma)
{
struct perf_mmap_event mmap_event;
- if (!atomic_read(&nr_munmap_tracking))
+ if (!atomic_read(&nr_mmap_counters))
return;
mmap_event = (struct perf_mmap_event){
- .file = file,
+ .vma = vma,
+ /* .file_name */
+ /* .file_size */
.event = {
- .header = { .type = PERF_EVENT_MUNMAP, },
- .pid = current->group_leader->pid,
- .tid = current->pid,
- .start = addr,
- .len = len,
- .pgoff = pgoff,
+ .header = {
+ .type = PERF_EVENT_MMAP,
+ .misc = 0,
+ /* .size */
+ },
+ /* .pid */
+ /* .tid */
+ .start = vma->vm_start,
+ .len = vma->vm_end - vma->vm_start,
+ .pgoff = vma->vm_pgoff,
},
};
}
/*
- * Log irq_period changes so that analyzing tools can re-normalize the
- * event flow.
+ * IRQ throttle logging
*/
-static void perf_log_period(struct perf_counter *counter, u64 period)
+static void perf_log_throttle(struct perf_counter *counter, int enable)
{
struct perf_output_handle handle;
int ret;
struct {
struct perf_event_header header;
u64 time;
- u64 period;
- } freq_event = {
+ u64 id;
+ u64 stream_id;
+ } throttle_event = {
.header = {
- .type = PERF_EVENT_PERIOD,
+ .type = PERF_EVENT_THROTTLE,
.misc = 0,
- .size = sizeof(freq_event),
+ .size = sizeof(throttle_event),
},
- .time = sched_clock(),
- .period = period,
+ .time = sched_clock(),
+ .id = primary_counter_id(counter),
+ .stream_id = counter->id,
};
- if (counter->hw.irq_period == period)
- return;
+ if (enable)
+ throttle_event.header.type = PERF_EVENT_UNTHROTTLE;
- ret = perf_output_begin(&handle, counter, sizeof(freq_event), 0, 0);
+ ret = perf_output_begin(&handle, counter, sizeof(throttle_event), 1, 0);
if (ret)
return;
- perf_output_put(&handle, freq_event);
+ perf_output_put(&handle, throttle_event);
perf_output_end(&handle);
}
/*
- * Generic counter overflow handling.
+ * Generic counter overflow handling, sampling.
*/
-int perf_counter_overflow(struct perf_counter *counter,
- int nmi, struct pt_regs *regs, u64 addr)
+int perf_counter_overflow(struct perf_counter *counter, int nmi,
+ struct perf_sample_data *data)
{
int events = atomic_read(&counter->event_limit);
+ int throttle = counter->pmu->unthrottle != NULL;
+ struct hw_perf_counter *hwc = &counter->hw;
int ret = 0;
- counter->hw.interrupts++;
+ if (!throttle) {
+ hwc->interrupts++;
+ } else {
+ if (hwc->interrupts != MAX_INTERRUPTS) {
+ hwc->interrupts++;
+ if (HZ * hwc->interrupts >
+ (u64)sysctl_perf_counter_sample_rate) {
+ hwc->interrupts = MAX_INTERRUPTS;
+ perf_log_throttle(counter, 0);
+ ret = 1;
+ }
+ } else {
+ /*
+ * Keep re-disabling counters even though on the previous
+ * pass we disabled it - just in case we raced with a
+ * sched-in and the counter got enabled again:
+ */
+ ret = 1;
+ }
+ }
+
+ if (counter->attr.freq) {
+ u64 now = sched_clock();
+ s64 delta = now - hwc->freq_stamp;
+
+ hwc->freq_stamp = now;
+
+ if (delta > 0 && delta < TICK_NSEC)
+ perf_adjust_period(counter, NSEC_PER_SEC / (int)delta);
+ }
/*
* XXX event_limit might not quite work as expected on inherited
perf_counter_disable(counter);
}
- perf_counter_output(counter, nmi, regs, addr);
+ perf_counter_output(counter, nmi, data);
return ret;
}
* Generic software counter infrastructure
*/
-static void perf_swcounter_update(struct perf_counter *counter)
+/*
+ * We directly increment counter->count and keep a second value in
+ * counter->hw.period_left to count intervals. This period counter
+ * is kept in the range [-sample_period, 0] so that we can use the
+ * sign as trigger.
+ */
+
+static u64 perf_swcounter_set_period(struct perf_counter *counter)
{
struct hw_perf_counter *hwc = &counter->hw;
- u64 prev, now;
- s64 delta;
+ u64 period = hwc->last_period;
+ u64 nr, offset;
+ s64 old, val;
+
+ hwc->last_period = hwc->sample_period;
again:
- prev = atomic64_read(&hwc->prev_count);
- now = atomic64_read(&hwc->count);
- if (atomic64_cmpxchg(&hwc->prev_count, prev, now) != prev)
- goto again;
+ old = val = atomic64_read(&hwc->period_left);
+ if (val < 0)
+ return 0;
- delta = now - prev;
+ nr = div64_u64(period + val, period);
+ offset = nr * period;
+ val -= offset;
+ if (atomic64_cmpxchg(&hwc->period_left, old, val) != old)
+ goto again;
- atomic64_add(delta, &counter->count);
- atomic64_sub(delta, &hwc->period_left);
+ return nr;
}
-static void perf_swcounter_set_period(struct perf_counter *counter)
+static void perf_swcounter_overflow(struct perf_counter *counter,
+ int nmi, struct perf_sample_data *data)
{
struct hw_perf_counter *hwc = &counter->hw;
- s64 left = atomic64_read(&hwc->period_left);
- s64 period = hwc->irq_period;
+ u64 overflow;
- if (unlikely(left <= -period)) {
- left = period;
- atomic64_set(&hwc->period_left, left);
- }
+ data->period = counter->hw.last_period;
+ overflow = perf_swcounter_set_period(counter);
- if (unlikely(left <= 0)) {
- left += period;
- atomic64_add(period, &hwc->period_left);
- }
+ if (hwc->interrupts == MAX_INTERRUPTS)
+ return;
- atomic64_set(&hwc->prev_count, -left);
- atomic64_set(&hwc->count, -left);
+ for (; overflow; overflow--) {
+ if (perf_counter_overflow(counter, nmi, data)) {
+ /*
+ * We inhibit the overflow from happening when
+ * hwc->interrupts == MAX_INTERRUPTS.
+ */
+ break;
+ }
+ }
}
-static enum hrtimer_restart perf_swcounter_hrtimer(struct hrtimer *hrtimer)
+static void perf_swcounter_unthrottle(struct perf_counter *counter)
{
- enum hrtimer_restart ret = HRTIMER_RESTART;
- struct perf_counter *counter;
- struct pt_regs *regs;
- u64 period;
-
- counter = container_of(hrtimer, struct perf_counter, hw.hrtimer);
- counter->pmu->read(counter);
-
- regs = get_irq_regs();
/*
- * In case we exclude kernel IPs or are somehow not in interrupt
- * context, provide the next best thing, the user IP.
+ * Nothing to do, we already reset hwc->interrupts.
*/
- if ((counter->hw_event.exclude_kernel || !regs) &&
- !counter->hw_event.exclude_user)
- regs = task_pt_regs(current);
+}
- if (regs) {
- if (perf_counter_overflow(counter, 0, regs, 0))
- ret = HRTIMER_NORESTART;
- }
+static void perf_swcounter_add(struct perf_counter *counter, u64 nr,
+ int nmi, struct perf_sample_data *data)
+{
+ struct hw_perf_counter *hwc = &counter->hw;
- period = max_t(u64, 10000, counter->hw.irq_period);
- hrtimer_forward_now(hrtimer, ns_to_ktime(period));
+ atomic64_add(nr, &counter->count);
- return ret;
+ if (!hwc->sample_period)
+ return;
+
+ if (!data->regs)
+ return;
+
+ if (!atomic64_add_negative(nr, &hwc->period_left))
+ perf_swcounter_overflow(counter, nmi, data);
}
-static void perf_swcounter_overflow(struct perf_counter *counter,
- int nmi, struct pt_regs *regs, u64 addr)
+static int perf_swcounter_is_counting(struct perf_counter *counter)
{
- perf_swcounter_update(counter);
- perf_swcounter_set_period(counter);
- if (perf_counter_overflow(counter, nmi, regs, addr))
- /* soft-disable the counter */
- ;
+ /*
+ * The counter is active, we're good!
+ */
+ if (counter->state == PERF_COUNTER_STATE_ACTIVE)
+ return 1;
+
+ /*
+ * The counter is off/error, not counting.
+ */
+ if (counter->state != PERF_COUNTER_STATE_INACTIVE)
+ return 0;
+ /*
+ * The counter is inactive, if the context is active
+ * we're part of a group that didn't make it on the 'pmu',
+ * not counting.
+ */
+ if (counter->ctx->is_active)
+ return 0;
+
+ /*
+ * We're inactive and the context is too, this means the
+ * task is scheduled out, we're counting events that happen
+ * to us, like migration events.
+ */
+ return 1;
}
static int perf_swcounter_match(struct perf_counter *counter,
- enum perf_event_types type,
+ enum perf_type_id type,
u32 event, struct pt_regs *regs)
{
- if (counter->state != PERF_COUNTER_STATE_ACTIVE)
+ if (!perf_swcounter_is_counting(counter))
return 0;
- if (perf_event_raw(&counter->hw_event))
+ if (counter->attr.type != type)
return 0;
-
- if (perf_event_type(&counter->hw_event) != type)
- return 0;
-
- if (perf_event_id(&counter->hw_event) != event)
+ if (counter->attr.config != event)
return 0;
- if (counter->hw_event.exclude_user && user_mode(regs))
- return 0;
+ if (regs) {
+ if (counter->attr.exclude_user && user_mode(regs))
+ return 0;
- if (counter->hw_event.exclude_kernel && !user_mode(regs))
- return 0;
+ if (counter->attr.exclude_kernel && !user_mode(regs))
+ return 0;
+ }
return 1;
}
-static void perf_swcounter_add(struct perf_counter *counter, u64 nr,
- int nmi, struct pt_regs *regs, u64 addr)
-{
- int neg = atomic64_add_negative(nr, &counter->hw.count);
- if (counter->hw.irq_period && !neg)
- perf_swcounter_overflow(counter, nmi, regs, addr);
-}
-
static void perf_swcounter_ctx_event(struct perf_counter_context *ctx,
- enum perf_event_types type, u32 event,
- u64 nr, int nmi, struct pt_regs *regs,
- u64 addr)
+ enum perf_type_id type,
+ u32 event, u64 nr, int nmi,
+ struct perf_sample_data *data)
{
struct perf_counter *counter;
rcu_read_lock();
list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) {
- if (perf_swcounter_match(counter, type, event, regs))
- perf_swcounter_add(counter, nr, nmi, regs, addr);
+ if (perf_swcounter_match(counter, type, event, data->regs))
+ perf_swcounter_add(counter, nr, nmi, data);
}
rcu_read_unlock();
}
return &cpuctx->recursion[0];
}
-static void __perf_swcounter_event(enum perf_event_types type, u32 event,
- u64 nr, int nmi, struct pt_regs *regs,
- u64 addr)
+static void do_perf_swcounter_event(enum perf_type_id type, u32 event,
+ u64 nr, int nmi,
+ struct perf_sample_data *data)
{
struct perf_cpu_context *cpuctx = &get_cpu_var(perf_cpu_context);
int *recursion = perf_swcounter_recursion_context(cpuctx);
+ struct perf_counter_context *ctx;
if (*recursion)
goto out;
barrier();
perf_swcounter_ctx_event(&cpuctx->ctx, type, event,
- nr, nmi, regs, addr);
- if (cpuctx->task_ctx) {
- perf_swcounter_ctx_event(cpuctx->task_ctx, type, event,
- nr, nmi, regs, addr);
- }
+ nr, nmi, data);
+ rcu_read_lock();
+ /*
+ * doesn't really matter which of the child contexts the
+ * events ends up in.
+ */
+ ctx = rcu_dereference(current->perf_counter_ctxp);
+ if (ctx)
+ perf_swcounter_ctx_event(ctx, type, event, nr, nmi, data);
+ rcu_read_unlock();
barrier();
(*recursion)--;
put_cpu_var(perf_cpu_context);
}
-void
-perf_swcounter_event(u32 event, u64 nr, int nmi, struct pt_regs *regs, u64 addr)
+void __perf_swcounter_event(u32 event, u64 nr, int nmi,
+ struct pt_regs *regs, u64 addr)
{
- __perf_swcounter_event(PERF_TYPE_SOFTWARE, event, nr, nmi, regs, addr);
+ struct perf_sample_data data = {
+ .regs = regs,
+ .addr = addr,
+ };
+
+ do_perf_swcounter_event(PERF_TYPE_SOFTWARE, event, nr, nmi, &data);
}
static void perf_swcounter_read(struct perf_counter *counter)
{
- perf_swcounter_update(counter);
}
static int perf_swcounter_enable(struct perf_counter *counter)
{
- perf_swcounter_set_period(counter);
+ struct hw_perf_counter *hwc = &counter->hw;
+
+ if (hwc->sample_period) {
+ hwc->last_period = hwc->sample_period;
+ perf_swcounter_set_period(counter);
+ }
return 0;
}
static void perf_swcounter_disable(struct perf_counter *counter)
{
- perf_swcounter_update(counter);
}
static const struct pmu perf_ops_generic = {
.enable = perf_swcounter_enable,
.disable = perf_swcounter_disable,
.read = perf_swcounter_read,
+ .unthrottle = perf_swcounter_unthrottle,
};
/*
+ * hrtimer based swcounter callback
+ */
+
+static enum hrtimer_restart perf_swcounter_hrtimer(struct hrtimer *hrtimer)
+{
+ enum hrtimer_restart ret = HRTIMER_RESTART;
+ struct perf_sample_data data;
+ struct perf_counter *counter;
+ u64 period;
+
+ counter = container_of(hrtimer, struct perf_counter, hw.hrtimer);
+ counter->pmu->read(counter);
+
+ data.addr = 0;
+ data.regs = get_irq_regs();
+ /*
+ * In case we exclude kernel IPs or are somehow not in interrupt
+ * context, provide the next best thing, the user IP.
+ */
+ if ((counter->attr.exclude_kernel || !data.regs) &&
+ !counter->attr.exclude_user)
+ data.regs = task_pt_regs(current);
+
+ if (data.regs) {
+ if (perf_counter_overflow(counter, 0, &data))
+ ret = HRTIMER_NORESTART;
+ }
+
+ period = max_t(u64, 10000, counter->hw.sample_period);
+ hrtimer_forward_now(hrtimer, ns_to_ktime(period));
+
+ return ret;
+}
+
+/*
* Software counter: cpu wall time clock
*/
atomic64_set(&hwc->prev_count, cpu_clock(cpu));
hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
hwc->hrtimer.function = perf_swcounter_hrtimer;
- if (hwc->irq_period) {
- u64 period = max_t(u64, 10000, hwc->irq_period);
+ if (hwc->sample_period) {
+ u64 period = max_t(u64, 10000, hwc->sample_period);
__hrtimer_start_range_ns(&hwc->hrtimer,
ns_to_ktime(period), 0,
HRTIMER_MODE_REL, 0);
static void cpu_clock_perf_counter_disable(struct perf_counter *counter)
{
- if (counter->hw.irq_period)
+ if (counter->hw.sample_period)
hrtimer_cancel(&counter->hw.hrtimer);
cpu_clock_perf_counter_update(counter);
}
atomic64_set(&hwc->prev_count, now);
hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
hwc->hrtimer.function = perf_swcounter_hrtimer;
- if (hwc->irq_period) {
- u64 period = max_t(u64, 10000, hwc->irq_period);
+ if (hwc->sample_period) {
+ u64 period = max_t(u64, 10000, hwc->sample_period);
__hrtimer_start_range_ns(&hwc->hrtimer,
ns_to_ktime(period), 0,
HRTIMER_MODE_REL, 0);
static void task_clock_perf_counter_disable(struct perf_counter *counter)
{
- if (counter->hw.irq_period)
+ if (counter->hw.sample_period)
hrtimer_cancel(&counter->hw.hrtimer);
task_clock_perf_counter_update(counter, counter->ctx->time);
.read = task_clock_perf_counter_read,
};
-/*
- * Software counter: cpu migrations
- */
-
-static inline u64 get_cpu_migrations(struct perf_counter *counter)
-{
- 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)
-{
- u64 prev, now;
- s64 delta;
-
- prev = atomic64_read(&counter->hw.prev_count);
- now = get_cpu_migrations(counter);
-
- atomic64_set(&counter->hw.prev_count, now);
-
- delta = now - prev;
-
- atomic64_add(delta, &counter->count);
-}
-
-static void cpu_migrations_perf_counter_read(struct perf_counter *counter)
-{
- cpu_migrations_perf_counter_update(counter);
-}
-
-static int cpu_migrations_perf_counter_enable(struct perf_counter *counter)
-{
- if (counter->prev_state <= PERF_COUNTER_STATE_OFF)
- atomic64_set(&counter->hw.prev_count,
- get_cpu_migrations(counter));
- return 0;
-}
-
-static void cpu_migrations_perf_counter_disable(struct perf_counter *counter)
-{
- cpu_migrations_perf_counter_update(counter);
-}
-
-static const struct pmu perf_ops_cpu_migrations = {
- .enable = cpu_migrations_perf_counter_enable,
- .disable = cpu_migrations_perf_counter_disable,
- .read = cpu_migrations_perf_counter_read,
-};
-
#ifdef CONFIG_EVENT_PROFILE
-void perf_tpcounter_event(int event_id)
+void perf_tpcounter_event(int event_id, u64 addr, u64 count, void *record,
+ int entry_size)
{
- struct pt_regs *regs = get_irq_regs();
+ struct perf_raw_record raw = {
+ .size = entry_size,
+ .data = record,
+ };
+
+ struct perf_sample_data data = {
+ .regs = get_irq_regs(),
+ .addr = addr,
+ .raw = &raw,
+ };
- if (!regs)
- regs = task_pt_regs(current);
+ if (!data.regs)
+ data.regs = task_pt_regs(current);
- __perf_swcounter_event(PERF_TYPE_TRACEPOINT, event_id, 1, 1, regs, 0);
+ do_perf_swcounter_event(PERF_TYPE_TRACEPOINT, event_id, count, 1, &data);
}
EXPORT_SYMBOL_GPL(perf_tpcounter_event);
static void tp_perf_counter_destroy(struct perf_counter *counter)
{
- ftrace_profile_disable(perf_event_id(&counter->hw_event));
+ ftrace_profile_disable(counter->attr.config);
}
static const struct pmu *tp_perf_counter_init(struct perf_counter *counter)
{
- int event_id = perf_event_id(&counter->hw_event);
- int ret;
+ /*
+ * Raw tracepoint data is a severe data leak, only allow root to
+ * have these.
+ */
+ if ((counter->attr.sample_type & PERF_SAMPLE_RAW) &&
+ !capable(CAP_SYS_ADMIN))
+ return ERR_PTR(-EPERM);
- ret = ftrace_profile_enable(event_id);
- if (ret)
+ if (ftrace_profile_enable(counter->attr.config))
return NULL;
counter->destroy = tp_perf_counter_destroy;
- counter->hw.irq_period = counter->hw_event.irq_period;
return &perf_ops_generic;
}
}
#endif
+atomic_t perf_swcounter_enabled[PERF_COUNT_SW_MAX];
+
+static void sw_perf_counter_destroy(struct perf_counter *counter)
+{
+ u64 event = counter->attr.config;
+
+ WARN_ON(counter->parent);
+
+ atomic_dec(&perf_swcounter_enabled[event]);
+}
+
static const struct pmu *sw_perf_counter_init(struct perf_counter *counter)
{
const struct pmu *pmu = NULL;
+ u64 event = counter->attr.config;
/*
* Software counters (currently) can't in general distinguish
* to be kernel events, and page faults are never hypervisor
* events.
*/
- switch (perf_event_id(&counter->hw_event)) {
- case PERF_COUNT_CPU_CLOCK:
+ switch (event) {
+ case PERF_COUNT_SW_CPU_CLOCK:
pmu = &perf_ops_cpu_clock;
break;
- case PERF_COUNT_TASK_CLOCK:
+ case PERF_COUNT_SW_TASK_CLOCK:
/*
* If the user instantiates this as a per-cpu counter,
* use the cpu_clock counter instead.
pmu = &perf_ops_cpu_clock;
break;
- case PERF_COUNT_PAGE_FAULTS:
- case PERF_COUNT_PAGE_FAULTS_MIN:
- case PERF_COUNT_PAGE_FAULTS_MAJ:
- case PERF_COUNT_CONTEXT_SWITCHES:
+ case PERF_COUNT_SW_PAGE_FAULTS:
+ case PERF_COUNT_SW_PAGE_FAULTS_MIN:
+ case PERF_COUNT_SW_PAGE_FAULTS_MAJ:
+ case PERF_COUNT_SW_CONTEXT_SWITCHES:
+ case PERF_COUNT_SW_CPU_MIGRATIONS:
+ if (!counter->parent) {
+ atomic_inc(&perf_swcounter_enabled[event]);
+ counter->destroy = sw_perf_counter_destroy;
+ }
pmu = &perf_ops_generic;
break;
- case PERF_COUNT_CPU_MIGRATIONS:
- if (!counter->hw_event.exclude_kernel)
- pmu = &perf_ops_cpu_migrations;
- break;
}
return pmu;
* Allocate and initialize a counter structure
*/
static struct perf_counter *
-perf_counter_alloc(struct perf_counter_hw_event *hw_event,
+perf_counter_alloc(struct perf_counter_attr *attr,
int cpu,
struct perf_counter_context *ctx,
struct perf_counter *group_leader,
+ struct perf_counter *parent_counter,
gfp_t gfpflags)
{
const struct pmu *pmu;
mutex_init(&counter->mmap_mutex);
- counter->cpu = cpu;
- counter->hw_event = *hw_event;
- counter->group_leader = group_leader;
- counter->pmu = NULL;
- counter->ctx = ctx;
- get_ctx(ctx);
+ counter->cpu = cpu;
+ counter->attr = *attr;
+ counter->group_leader = group_leader;
+ counter->pmu = NULL;
+ counter->ctx = ctx;
+ counter->oncpu = -1;
- counter->state = PERF_COUNTER_STATE_INACTIVE;
- if (hw_event->disabled)
+ counter->parent = parent_counter;
+
+ counter->ns = get_pid_ns(current->nsproxy->pid_ns);
+ counter->id = atomic64_inc_return(&perf_counter_id);
+
+ counter->state = PERF_COUNTER_STATE_INACTIVE;
+
+ if (attr->disabled)
counter->state = PERF_COUNTER_STATE_OFF;
pmu = NULL;
hwc = &counter->hw;
- if (hw_event->freq && hw_event->irq_freq)
- hwc->irq_period = div64_u64(TICK_NSEC, hw_event->irq_freq);
- else
- hwc->irq_period = hw_event->irq_period;
+ hwc->sample_period = attr->sample_period;
+ if (attr->freq && attr->sample_freq)
+ hwc->sample_period = 1;
+
+ atomic64_set(&hwc->period_left, hwc->sample_period);
/*
- * we currently do not support PERF_RECORD_GROUP on inherited counters
+ * we currently do not support PERF_FORMAT_GROUP on inherited counters
*/
- if (hw_event->inherit && (hw_event->record_type & PERF_RECORD_GROUP))
- goto done;
-
- if (perf_event_raw(hw_event)) {
- pmu = hw_perf_counter_init(counter);
+ if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP))
goto done;
- }
- switch (perf_event_type(hw_event)) {
+ switch (attr->type) {
+ case PERF_TYPE_RAW:
case PERF_TYPE_HARDWARE:
+ case PERF_TYPE_HW_CACHE:
pmu = hw_perf_counter_init(counter);
break;
case PERF_TYPE_TRACEPOINT:
pmu = tp_perf_counter_init(counter);
break;
+
+ default:
+ break;
}
done:
err = 0;
err = PTR_ERR(pmu);
if (err) {
+ if (counter->ns)
+ put_pid_ns(counter->ns);
kfree(counter);
return ERR_PTR(err);
}
counter->pmu = pmu;
- atomic_inc(&nr_counters);
- if (counter->hw_event.mmap)
- atomic_inc(&nr_mmap_tracking);
- if (counter->hw_event.munmap)
- atomic_inc(&nr_munmap_tracking);
- if (counter->hw_event.comm)
- atomic_inc(&nr_comm_tracking);
+ if (!counter->parent) {
+ atomic_inc(&nr_counters);
+ if (counter->attr.mmap)
+ atomic_inc(&nr_mmap_counters);
+ if (counter->attr.comm)
+ atomic_inc(&nr_comm_counters);
+ if (counter->attr.task)
+ atomic_inc(&nr_task_counters);
+ }
return counter;
}
+static int perf_copy_attr(struct perf_counter_attr __user *uattr,
+ struct perf_counter_attr *attr)
+{
+ int ret;
+ u32 size;
+
+ if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0))
+ return -EFAULT;
+
+ /*
+ * zero the full structure, so that a short copy will be nice.
+ */
+ memset(attr, 0, sizeof(*attr));
+
+ ret = get_user(size, &uattr->size);
+ if (ret)
+ return ret;
+
+ if (size > PAGE_SIZE) /* silly large */
+ goto err_size;
+
+ if (!size) /* abi compat */
+ size = PERF_ATTR_SIZE_VER0;
+
+ if (size < PERF_ATTR_SIZE_VER0)
+ goto err_size;
+
+ /*
+ * If we're handed a bigger struct than we know of,
+ * ensure all the unknown bits are 0.
+ */
+ if (size > sizeof(*attr)) {
+ unsigned long val;
+ unsigned long __user *addr;
+ unsigned long __user *end;
+
+ addr = PTR_ALIGN((void __user *)uattr + sizeof(*attr),
+ sizeof(unsigned long));
+ end = PTR_ALIGN((void __user *)uattr + size,
+ sizeof(unsigned long));
+
+ for (; addr < end; addr += sizeof(unsigned long)) {
+ ret = get_user(val, addr);
+ if (ret)
+ return ret;
+ if (val)
+ goto err_size;
+ }
+ }
+
+ ret = copy_from_user(attr, uattr, size);
+ if (ret)
+ return -EFAULT;
+
+ /*
+ * If the type exists, the corresponding creation will verify
+ * the attr->config.
+ */
+ if (attr->type >= PERF_TYPE_MAX)
+ return -EINVAL;
+
+ if (attr->__reserved_1 || attr->__reserved_2 || attr->__reserved_3)
+ return -EINVAL;
+
+ if (attr->sample_type & ~(PERF_SAMPLE_MAX-1))
+ return -EINVAL;
+
+ if (attr->read_format & ~(PERF_FORMAT_MAX-1))
+ return -EINVAL;
+
+out:
+ return ret;
+
+err_size:
+ put_user(sizeof(*attr), &uattr->size);
+ ret = -E2BIG;
+ goto out;
+}
+
/**
* sys_perf_counter_open - open a performance counter, associate it to a task/cpu
*
- * @hw_event_uptr: event type attributes for monitoring/sampling
+ * @attr_uptr: event type attributes for monitoring/sampling
* @pid: target pid
* @cpu: target cpu
* @group_fd: group leader counter fd
*/
SYSCALL_DEFINE5(perf_counter_open,
- const struct perf_counter_hw_event __user *, hw_event_uptr,
+ struct perf_counter_attr __user *, attr_uptr,
pid_t, pid, int, cpu, int, group_fd, unsigned long, flags)
{
struct perf_counter *counter, *group_leader;
- struct perf_counter_hw_event hw_event;
+ struct perf_counter_attr attr;
struct perf_counter_context *ctx;
struct file *counter_file = NULL;
struct file *group_file = NULL;
if (flags)
return -EINVAL;
- if (copy_from_user(&hw_event, hw_event_uptr, sizeof(hw_event)) != 0)
- return -EFAULT;
+ ret = perf_copy_attr(attr_uptr, &attr);
+ if (ret)
+ return ret;
+
+ if (!attr.exclude_kernel) {
+ if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
+ return -EACCES;
+ }
+
+ if (attr.freq) {
+ if (attr.sample_freq > sysctl_perf_counter_sample_rate)
+ return -EINVAL;
+ }
/*
* Get the target context (task or percpu):
/*
* Only a group leader can be exclusive or pinned
*/
- if (hw_event.exclusive || hw_event.pinned)
+ if (attr.exclusive || attr.pinned)
goto err_put_context;
}
- counter = perf_counter_alloc(&hw_event, cpu, ctx, group_leader,
- GFP_KERNEL);
+ counter = perf_counter_alloc(&attr, cpu, ctx, group_leader,
+ NULL, GFP_KERNEL);
ret = PTR_ERR(counter);
if (IS_ERR(counter))
goto err_put_context;
goto err_free_put_context;
counter->filp = counter_file;
+ WARN_ON_ONCE(ctx->parent_ctx);
mutex_lock(&ctx->mutex);
perf_install_in_context(ctx, counter, cpu);
+ ++ctx->generation;
mutex_unlock(&ctx->mutex);
+ counter->owner = current;
+ get_task_struct(current);
+ mutex_lock(¤t->perf_counter_mutex);
+ list_add_tail(&counter->owner_entry, ¤t->perf_counter_list);
+ mutex_unlock(¤t->perf_counter_mutex);
+
fput_light(counter_file, fput_needed2);
out_fput:
kfree(counter);
err_put_context:
- put_context(ctx);
+ put_ctx(ctx);
goto out_fput;
}
if (parent_counter->parent)
parent_counter = parent_counter->parent;
- child_counter = perf_counter_alloc(&parent_counter->hw_event,
+ child_counter = perf_counter_alloc(&parent_counter->attr,
parent_counter->cpu, child_ctx,
- group_leader, GFP_KERNEL);
+ group_leader, parent_counter,
+ GFP_KERNEL);
if (IS_ERR(child_counter))
return child_counter;
+ get_ctx(child_ctx);
/*
* Make the child state follow the state of the parent counter,
- * not its hw_event.disabled bit. We hold the parent's mutex,
- * so we won't race with perf_counter_{en,dis}able_family.
+ * not its attr.disabled bit. We hold the parent's mutex,
+ * so we won't race with perf_counter_{en, dis}able_family.
*/
if (parent_counter->state >= PERF_COUNTER_STATE_INACTIVE)
child_counter->state = PERF_COUNTER_STATE_INACTIVE;
else
child_counter->state = PERF_COUNTER_STATE_OFF;
+ if (parent_counter->attr.freq)
+ child_counter->hw.sample_period = parent_counter->hw.sample_period;
+
/*
* Link it up in the child's context:
*/
add_counter_to_ctx(child_counter, child_ctx);
- child_counter->parent = parent_counter;
- /*
- * inherit into child's child as well:
- */
- child_counter->hw_event.inherit = 1;
-
/*
* Get a reference to the parent filp - we will fput it
* when the child counter exits. This is safe to do because
/*
* Link this into the parent counter's child list
*/
+ WARN_ON_ONCE(parent_counter->ctx->parent_ctx);
mutex_lock(&parent_counter->child_mutex);
list_add_tail(&child_counter->child_list, &parent_counter->child_list);
mutex_unlock(&parent_counter->child_mutex);
}
static void sync_child_counter(struct perf_counter *child_counter,
- struct perf_counter *parent_counter)
+ struct task_struct *child)
{
+ struct perf_counter *parent_counter = child_counter->parent;
u64 child_val;
+ if (child_counter->attr.inherit_stat)
+ perf_counter_read_event(child_counter, child);
+
child_val = atomic64_read(&child_counter->count);
/*
/*
* Remove this counter from the parent's list
*/
+ WARN_ON_ONCE(parent_counter->ctx->parent_ctx);
mutex_lock(&parent_counter->child_mutex);
list_del_init(&child_counter->child_list);
mutex_unlock(&parent_counter->child_mutex);
}
static void
-__perf_counter_exit_task(struct task_struct *child,
- struct perf_counter *child_counter,
- struct perf_counter_context *child_ctx)
+__perf_counter_exit_task(struct perf_counter *child_counter,
+ struct perf_counter_context *child_ctx,
+ struct task_struct *child)
{
struct perf_counter *parent_counter;
update_counter_times(child_counter);
-
- spin_lock_irq(&child_ctx->lock);
- list_del_counter(child_counter, child_ctx);
- spin_unlock_irq(&child_ctx->lock);
+ perf_counter_remove_from_context(child_counter);
parent_counter = child_counter->parent;
/*
* counters need to be zapped - but otherwise linger.
*/
if (parent_counter) {
- sync_child_counter(child_counter, parent_counter);
+ sync_child_counter(child_counter, child);
free_counter(child_counter);
}
}
/*
* When a child task exits, feed back counter values to parent counters.
- *
- * Note: we may be running in child context, but the PID is not hashed
- * anymore so new counters will not be added.
- * (XXX not sure that is true when we get called from flush_old_exec.
- * -- paulus)
*/
void perf_counter_exit_task(struct task_struct *child)
{
struct perf_counter_context *child_ctx;
unsigned long flags;
- WARN_ON_ONCE(child != current);
-
- child_ctx = child->perf_counter_ctxp;
-
- if (likely(!child_ctx))
+ if (likely(!child->perf_counter_ctxp)) {
+ perf_counter_task(child, NULL, 0);
return;
+ }
local_irq_save(flags);
+ /*
+ * We can't reschedule here because interrupts are disabled,
+ * and either child is current or it is a task that can't be
+ * scheduled, so we are now safe from rescheduling changing
+ * our context.
+ */
+ child_ctx = child->perf_counter_ctxp;
__perf_counter_task_sched_out(child_ctx);
+
+ /*
+ * Take the context lock here so that if find_get_context is
+ * reading child->perf_counter_ctxp, we wait until it has
+ * incremented the context's refcount before we do put_ctx below.
+ */
+ spin_lock(&child_ctx->lock);
child->perf_counter_ctxp = NULL;
- local_irq_restore(flags);
+ /*
+ * If this context is a clone; unclone it so it can't get
+ * swapped to another process while we're removing all
+ * the counters from it.
+ */
+ unclone_ctx(child_ctx);
+ spin_unlock_irqrestore(&child_ctx->lock, flags);
+
+ /*
+ * Report the task dead after unscheduling the counters so that we
+ * won't get any samples after PERF_EVENT_EXIT. We can however still
+ * get a few PERF_EVENT_READ events.
+ */
+ perf_counter_task(child, child_ctx, 0);
- mutex_lock(&child_ctx->mutex);
+ /*
+ * We can recurse on the same lock type through:
+ *
+ * __perf_counter_exit_task()
+ * sync_child_counter()
+ * fput(parent_counter->filp)
+ * perf_release()
+ * mutex_lock(&ctx->mutex)
+ *
+ * But since its the parent context it won't be the same instance.
+ */
+ mutex_lock_nested(&child_ctx->mutex, SINGLE_DEPTH_NESTING);
again:
list_for_each_entry_safe(child_counter, tmp, &child_ctx->counter_list,
list_entry)
- __perf_counter_exit_task(child, child_counter, child_ctx);
+ __perf_counter_exit_task(child_counter, child_ctx, child);
/*
* If the last counter was a group counter, it will have appended all
}
/*
+ * free an unexposed, unused context as created by inheritance by
+ * init_task below, used by fork() in case of fail.
+ */
+void perf_counter_free_task(struct task_struct *task)
+{
+ struct perf_counter_context *ctx = task->perf_counter_ctxp;
+ struct perf_counter *counter, *tmp;
+
+ if (!ctx)
+ return;
+
+ mutex_lock(&ctx->mutex);
+again:
+ list_for_each_entry_safe(counter, tmp, &ctx->counter_list, list_entry) {
+ struct perf_counter *parent = counter->parent;
+
+ if (WARN_ON_ONCE(!parent))
+ continue;
+
+ mutex_lock(&parent->child_mutex);
+ list_del_init(&counter->child_list);
+ mutex_unlock(&parent->child_mutex);
+
+ fput(parent->filp);
+
+ list_del_counter(counter, ctx);
+ free_counter(counter);
+ }
+
+ if (!list_empty(&ctx->counter_list))
+ goto again;
+
+ mutex_unlock(&ctx->mutex);
+
+ put_ctx(ctx);
+}
+
+/*
* Initialize the perf_counter context in task_struct
*/
-void perf_counter_init_task(struct task_struct *child)
+int perf_counter_init_task(struct task_struct *child)
{
struct perf_counter_context *child_ctx, *parent_ctx;
+ struct perf_counter_context *cloned_ctx;
struct perf_counter *counter;
struct task_struct *parent = current;
int inherited_all = 1;
+ int ret = 0;
child->perf_counter_ctxp = NULL;
+ mutex_init(&child->perf_counter_mutex);
+ INIT_LIST_HEAD(&child->perf_counter_list);
+
+ if (likely(!parent->perf_counter_ctxp))
+ return 0;
+
/*
* This is executed from the parent task context, so inherit
* counters that have been marked for cloning.
child_ctx = kmalloc(sizeof(struct perf_counter_context), GFP_KERNEL);
if (!child_ctx)
- return;
-
- parent_ctx = parent->perf_counter_ctxp;
- if (likely(!parent_ctx || !parent_ctx->nr_counters))
- return;
+ return -ENOMEM;
__perf_counter_init_context(child_ctx, child);
child->perf_counter_ctxp = child_ctx;
+ get_task_struct(child);
+
+ /*
+ * If the parent's context is a clone, pin it so it won't get
+ * swapped under us.
+ */
+ parent_ctx = perf_pin_task_context(parent);
+
+ /*
+ * No need to check if parent_ctx != NULL here; since we saw
+ * it non-NULL earlier, the only reason for it to become NULL
+ * is if we exit, and since we're currently in the middle of
+ * a fork we can't be exiting at the same time.
+ */
/*
* Lock the parent list. No need to lock the child - not PID
if (counter != counter->group_leader)
continue;
- if (!counter->hw_event.inherit) {
+ if (!counter->attr.inherit) {
inherited_all = 0;
continue;
}
- if (inherit_group(counter, parent,
- parent_ctx, child, child_ctx)) {
+ ret = inherit_group(counter, parent, parent_ctx,
+ child, child_ctx);
+ if (ret) {
inherited_all = 0;
break;
}
/*
* Mark the child context as a clone of the parent
* context, or of whatever the parent is a clone of.
+ * Note that if the parent is a clone, it could get
+ * uncloned at any point, but that doesn't matter
+ * because the list of counters and the generation
+ * count can't have changed since we took the mutex.
*/
- if (parent_ctx->parent_ctx) {
- child_ctx->parent_ctx = parent_ctx->parent_ctx;
+ cloned_ctx = rcu_dereference(parent_ctx->parent_ctx);
+ if (cloned_ctx) {
+ child_ctx->parent_ctx = cloned_ctx;
child_ctx->parent_gen = parent_ctx->parent_gen;
} else {
child_ctx->parent_ctx = parent_ctx;
}
mutex_unlock(&parent_ctx->mutex);
+
+ perf_unpin_context(parent_ctx);
+
+ return ret;
}
static void __cpuinit perf_counter_init_cpu(int cpu)
perf_counter_init_cpu(cpu);
break;
+ case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
+ hw_perf_counter_setup_online(cpu);
+ break;
+
case CPU_DOWN_PREPARE:
case CPU_DOWN_PREPARE_FROZEN:
perf_counter_exit_cpu(cpu);
return NOTIFY_OK;
}
+/*
+ * This has to have a higher priority than migration_notifier in sched.c.
+ */
static struct notifier_block __cpuinitdata perf_cpu_nb = {
.notifier_call = perf_cpu_notify,
+ .priority = 20,
};
void __init perf_counter_init(void)
{
perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_UP_PREPARE,
(void *)(long)smp_processor_id());
+ perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_ONLINE,
+ (void *)(long)smp_processor_id());
register_cpu_notifier(&perf_cpu_nb);
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff