static int perf_sample_allowed_ns __read_mostly =
DEFAULT_SAMPLE_PERIOD_NS * DEFAULT_CPU_TIME_MAX_PERCENT / 100;
-void update_perf_cpu_limits(void)
+static void update_perf_cpu_limits(void)
{
u64 tmp = perf_sample_period_ns;
* mode SWOUT : schedule out everything
* mode SWIN : schedule in based on cgroup for next
*/
-void perf_cgroup_switch(struct task_struct *task, int mode)
+static void perf_cgroup_switch(struct task_struct *task, int mode)
{
struct perf_cpu_context *cpuctx;
struct pmu *pmu;
PERF_EVENT_STATE_INACTIVE;
}
-/*
- * Called at perf_event creation and when events are attached/detached from a
- * group.
- */
-static void perf_event__read_size(struct perf_event *event)
+static void __perf_event_read_size(struct perf_event *event, int nr_siblings)
{
int entry = sizeof(u64); /* value */
int size = 0;
entry += sizeof(u64);
if (event->attr.read_format & PERF_FORMAT_GROUP) {
- nr += event->group_leader->nr_siblings;
+ nr += nr_siblings;
size += sizeof(u64);
}
event->read_size = size;
}
-static void perf_event__header_size(struct perf_event *event)
+static void __perf_event_header_size(struct perf_event *event, u64 sample_type)
{
struct perf_sample_data *data;
- u64 sample_type = event->attr.sample_type;
u16 size = 0;
- perf_event__read_size(event);
-
if (sample_type & PERF_SAMPLE_IP)
size += sizeof(data->ip);
event->header_size = size;
}
+/*
+ * Called at perf_event creation and when events are attached/detached from a
+ * group.
+ */
+static void perf_event__header_size(struct perf_event *event)
+{
+ __perf_event_read_size(event,
+ event->group_leader->nr_siblings);
+ __perf_event_header_size(event, event->attr.sample_type);
+}
+
static void perf_event__id_header_size(struct perf_event *event)
{
struct perf_sample_data *data;
event->id_header_size = size;
}
+static bool perf_event_validate_size(struct perf_event *event)
+{
+ /*
+ * The values computed here will be over-written when we actually
+ * attach the event.
+ */
+ __perf_event_read_size(event, event->group_leader->nr_siblings + 1);
+ __perf_event_header_size(event, event->attr.sample_type & ~PERF_SAMPLE_READ);
+ perf_event__id_header_size(event);
+
+ /*
+ * Sum the lot; should not exceed the 64k limit we have on records.
+ * Conservative limit to allow for callchains and other variable fields.
+ */
+ if (event->read_size + event->header_size +
+ event->id_header_size + sizeof(struct perf_event_header) >= 16*1024)
+ return false;
+
+ return true;
+}
+
static void perf_group_attach(struct perf_event *event)
{
struct perf_event *group_leader = event->group_leader, *pos;
if (group_event->state == PERF_EVENT_STATE_OFF)
return 0;
- pmu->start_txn(pmu);
+ pmu->start_txn(pmu, PERF_PMU_TXN_ADD);
if (event_sched_in(group_event, cpuctx, ctx)) {
pmu->cancel_txn(pmu);
rcu_read_unlock();
}
+struct perf_read_data {
+ struct perf_event *event;
+ bool group;
+ int ret;
+};
+
/*
* Cross CPU call to read the hardware event
*/
static void __perf_event_read(void *info)
{
- struct perf_event *event = info;
+ struct perf_read_data *data = info;
+ struct perf_event *sub, *event = data->event;
struct perf_event_context *ctx = event->ctx;
struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
+ struct pmu *pmu = event->pmu;
/*
* If this is a task context, we need to check whether it is
update_context_time(ctx);
update_cgrp_time_from_event(event);
}
+
update_event_times(event);
- if (event->state == PERF_EVENT_STATE_ACTIVE)
- event->pmu->read(event);
+ if (event->state != PERF_EVENT_STATE_ACTIVE)
+ goto unlock;
+
+ if (!data->group) {
+ pmu->read(event);
+ data->ret = 0;
+ goto unlock;
+ }
+
+ pmu->start_txn(pmu, PERF_PMU_TXN_READ);
+
+ pmu->read(event);
+
+ list_for_each_entry(sub, &event->sibling_list, group_entry) {
+ update_event_times(sub);
+ if (sub->state == PERF_EVENT_STATE_ACTIVE) {
+ /*
+ * Use sibling's PMU rather than @event's since
+ * sibling could be on different (eg: software) PMU.
+ */
+ sub->pmu->read(sub);
+ }
+ }
+
+ data->ret = pmu->commit_txn(pmu);
+
+unlock:
raw_spin_unlock(&ctx->lock);
}
return val;
}
-static u64 perf_event_read(struct perf_event *event)
+static int perf_event_read(struct perf_event *event, bool group)
{
+ int ret = 0;
+
/*
* If event is enabled and currently active on a CPU, update the
* value in the event structure:
*/
if (event->state == PERF_EVENT_STATE_ACTIVE) {
+ struct perf_read_data data = {
+ .event = event,
+ .group = group,
+ .ret = 0,
+ };
smp_call_function_single(event->oncpu,
- __perf_event_read, event, 1);
+ __perf_event_read, &data, 1);
+ ret = data.ret;
} else if (event->state == PERF_EVENT_STATE_INACTIVE) {
struct perf_event_context *ctx = event->ctx;
unsigned long flags;
update_context_time(ctx);
update_cgrp_time_from_event(event);
}
- update_event_times(event);
+ if (group)
+ update_group_times(event);
+ else
+ update_event_times(event);
raw_spin_unlock_irqrestore(&ctx->lock, flags);
}
- return perf_event_count(event);
+ return ret;
}
/*
* see the comment there.
*
* 2) there is a lock-inversion with mmap_sem through
- * perf_event_read_group(), which takes faults while
+ * perf_read_group(), which takes faults while
* holding ctx->mutex, however this is called after
* the last filedesc died, so there is no possibility
* to trigger the AB-BA case.
*running = 0;
mutex_lock(&event->child_mutex);
- total += perf_event_read(event);
+
+ (void)perf_event_read(event, false);
+ total += perf_event_count(event);
+
*enabled += event->total_time_enabled +
atomic64_read(&event->child_total_time_enabled);
*running += event->total_time_running +
atomic64_read(&event->child_total_time_running);
list_for_each_entry(child, &event->child_list, child_list) {
- total += perf_event_read(child);
+ (void)perf_event_read(child, false);
+ total += perf_event_count(child);
*enabled += child->total_time_enabled;
*running += child->total_time_running;
}
}
EXPORT_SYMBOL_GPL(perf_event_read_value);
-static int perf_event_read_group(struct perf_event *event,
- u64 read_format, char __user *buf)
+static int __perf_read_group_add(struct perf_event *leader,
+ u64 read_format, u64 *values)
{
- struct perf_event *leader = event->group_leader, *sub;
- struct perf_event_context *ctx = leader->ctx;
- int n = 0, size = 0, ret;
- u64 count, enabled, running;
- u64 values[5];
+ struct perf_event *sub;
+ int n = 1; /* skip @nr */
+ int ret;
- lockdep_assert_held(&ctx->mutex);
+ ret = perf_event_read(leader, true);
+ if (ret)
+ return ret;
- count = perf_event_read_value(leader, &enabled, &running);
+ /*
+ * Since we co-schedule groups, {enabled,running} times of siblings
+ * will be identical to those of the leader, so we only publish one
+ * set.
+ */
+ if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
+ values[n++] += leader->total_time_enabled +
+ atomic64_read(&leader->child_total_time_enabled);
+ }
- values[n++] = 1 + leader->nr_siblings;
- if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
- values[n++] = enabled;
- if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
- values[n++] = running;
- values[n++] = count;
+ if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
+ values[n++] += leader->total_time_running +
+ atomic64_read(&leader->child_total_time_running);
+ }
+
+ /*
+ * Write {count,id} tuples for every sibling.
+ */
+ values[n++] += perf_event_count(leader);
if (read_format & PERF_FORMAT_ID)
values[n++] = primary_event_id(leader);
- size = n * sizeof(u64);
+ list_for_each_entry(sub, &leader->sibling_list, group_entry) {
+ values[n++] += perf_event_count(sub);
+ if (read_format & PERF_FORMAT_ID)
+ values[n++] = primary_event_id(sub);
+ }
- if (copy_to_user(buf, values, size))
- return -EFAULT;
+ return 0;
+}
- ret = size;
+static int perf_read_group(struct perf_event *event,
+ u64 read_format, char __user *buf)
+{
+ struct perf_event *leader = event->group_leader, *child;
+ struct perf_event_context *ctx = leader->ctx;
+ int ret;
+ u64 *values;
- list_for_each_entry(sub, &leader->sibling_list, group_entry) {
- n = 0;
+ lockdep_assert_held(&ctx->mutex);
- values[n++] = perf_event_read_value(sub, &enabled, &running);
- if (read_format & PERF_FORMAT_ID)
- values[n++] = primary_event_id(sub);
+ values = kzalloc(event->read_size, GFP_KERNEL);
+ if (!values)
+ return -ENOMEM;
- size = n * sizeof(u64);
+ values[0] = 1 + leader->nr_siblings;
- if (copy_to_user(buf + ret, values, size)) {
- return -EFAULT;
- }
+ /*
+ * By locking the child_mutex of the leader we effectively
+ * lock the child list of all siblings.. XXX explain how.
+ */
+ mutex_lock(&leader->child_mutex);
+
+ ret = __perf_read_group_add(leader, read_format, values);
+ if (ret)
+ goto unlock;
- ret += size;
+ list_for_each_entry(child, &leader->child_list, child_list) {
+ ret = __perf_read_group_add(child, read_format, values);
+ if (ret)
+ goto unlock;
}
+ mutex_unlock(&leader->child_mutex);
+
+ ret = event->read_size;
+ if (copy_to_user(buf, values, event->read_size))
+ ret = -EFAULT;
+ goto out;
+
+unlock:
+ mutex_unlock(&leader->child_mutex);
+out:
+ kfree(values);
return ret;
}
-static int perf_event_read_one(struct perf_event *event,
+static int perf_read_one(struct perf_event *event,
u64 read_format, char __user *buf)
{
u64 enabled, running;
* Read the performance event - simple non blocking version for now
*/
static ssize_t
-perf_read_hw(struct perf_event *event, char __user *buf, size_t count)
+__perf_read(struct perf_event *event, char __user *buf, size_t count)
{
u64 read_format = event->attr.read_format;
int ret;
WARN_ON_ONCE(event->ctx->parent_ctx);
if (read_format & PERF_FORMAT_GROUP)
- ret = perf_event_read_group(event, read_format, buf);
+ ret = perf_read_group(event, read_format, buf);
else
- ret = perf_event_read_one(event, read_format, buf);
+ ret = perf_read_one(event, read_format, buf);
return ret;
}
int ret;
ctx = perf_event_ctx_lock(event);
- ret = perf_read_hw(event, buf, count);
+ ret = __perf_read(event, buf, count);
perf_event_ctx_unlock(event, ctx);
return ret;
static void _perf_event_reset(struct perf_event *event)
{
- (void)perf_event_read(event);
+ (void)perf_event_read(event, false);
local64_set(&event->count, 0);
perf_event_update_userpage(event);
}
if (sample_type & PERF_SAMPLE_RAW) {
if (data->raw) {
- perf_output_put(handle, data->raw->size);
- __output_copy(handle, data->raw->data,
- data->raw->size);
+ u32 raw_size = data->raw->size;
+ u32 real_size = round_up(raw_size + sizeof(u32),
+ sizeof(u64)) - sizeof(u32);
+ u64 zero = 0;
+
+ perf_output_put(handle, real_size);
+ __output_copy(handle, data->raw->data, raw_size);
+ if (real_size - raw_size)
+ __output_copy(handle, &zero, real_size - raw_size);
} else {
struct {
u32 size;
else
size += sizeof(u32);
- WARN_ON_ONCE(size & (sizeof(u64)-1));
- header->size += size;
+ header->size += round_up(size, sizeof(u64));
}
if (sample_type & PERF_SAMPLE_BRANCH_STACK) {
{
}
+static void perf_pmu_nop_txn(struct pmu *pmu, unsigned int flags)
+{
+}
+
static int perf_pmu_nop_int(struct pmu *pmu)
{
return 0;
}
-static void perf_pmu_start_txn(struct pmu *pmu)
+static DEFINE_PER_CPU(unsigned int, nop_txn_flags);
+
+static void perf_pmu_start_txn(struct pmu *pmu, unsigned int flags)
{
+ __this_cpu_write(nop_txn_flags, flags);
+
+ if (flags & ~PERF_PMU_TXN_ADD)
+ return;
+
perf_pmu_disable(pmu);
}
static int perf_pmu_commit_txn(struct pmu *pmu)
{
+ unsigned int flags = __this_cpu_read(nop_txn_flags);
+
+ __this_cpu_write(nop_txn_flags, 0);
+
+ if (flags & ~PERF_PMU_TXN_ADD)
+ return 0;
+
perf_pmu_enable(pmu);
return 0;
}
static void perf_pmu_cancel_txn(struct pmu *pmu)
{
+ unsigned int flags = __this_cpu_read(nop_txn_flags);
+
+ __this_cpu_write(nop_txn_flags, 0);
+
+ if (flags & ~PERF_PMU_TXN_ADD)
+ return;
+
perf_pmu_enable(pmu);
}
pmu->commit_txn = perf_pmu_commit_txn;
pmu->cancel_txn = perf_pmu_cancel_txn;
} else {
- pmu->start_txn = perf_pmu_nop_void;
+ pmu->start_txn = perf_pmu_nop_txn;
pmu->commit_txn = perf_pmu_nop_int;
pmu->cancel_txn = perf_pmu_nop_void;
}
return ret;
}
-struct pmu *perf_init_event(struct perf_event *event)
+static struct pmu *perf_init_event(struct perf_event *event)
{
struct pmu *pmu = NULL;
int idx;
if (move_group) {
gctx = group_leader->ctx;
+ mutex_lock_double(&gctx->mutex, &ctx->mutex);
+ } else {
+ mutex_lock(&ctx->mutex);
+ }
+ if (!perf_event_validate_size(event)) {
+ err = -E2BIG;
+ goto err_locked;
+ }
+
+ /*
+ * Must be under the same ctx::mutex as perf_install_in_context(),
+ * because we need to serialize with concurrent event creation.
+ */
+ if (!exclusive_event_installable(event, ctx)) {
+ /* exclusive and group stuff are assumed mutually exclusive */
+ WARN_ON_ONCE(move_group);
+
+ err = -EBUSY;
+ goto err_locked;
+ }
+
+ WARN_ON_ONCE(ctx->parent_ctx);
+
+ if (move_group) {
/*
* See perf_event_ctx_lock() for comments on the details
* of swizzling perf_event::ctx.
*/
- mutex_lock_double(&gctx->mutex, &ctx->mutex);
-
perf_remove_from_context(group_leader, false);
list_for_each_entry(sibling, &group_leader->sibling_list,
perf_remove_from_context(sibling, false);
put_ctx(gctx);
}
- } else {
- mutex_lock(&ctx->mutex);
- }
- WARN_ON_ONCE(ctx->parent_ctx);
-
- if (move_group) {
/*
* Wait for everybody to stop referencing the events through
* the old lists, before installing it on new lists.
perf_event__state_init(group_leader);
perf_install_in_context(ctx, group_leader, group_leader->cpu);
get_ctx(ctx);
- }
- if (!exclusive_event_installable(event, ctx)) {
- err = -EBUSY;
- mutex_unlock(&ctx->mutex);
- fput(event_file);
- goto err_context;
+ /*
+ * Now that all events are installed in @ctx, nothing
+ * references @gctx anymore, so drop the last reference we have
+ * on it.
+ */
+ put_ctx(gctx);
}
+ /*
+ * Precalculate sample_data sizes; do while holding ctx::mutex such
+ * that we're serialized against further additions and before
+ * perf_install_in_context() which is the point the event is active and
+ * can use these values.
+ */
+ perf_event__header_size(event);
+ perf_event__id_header_size(event);
+
perf_install_in_context(ctx, event, event->cpu);
perf_unpin_context(ctx);
- if (move_group) {
+ if (move_group)
mutex_unlock(&gctx->mutex);
- put_ctx(gctx);
- }
mutex_unlock(&ctx->mutex);
put_online_cpus();
list_add_tail(&event->owner_entry, ¤t->perf_event_list);
mutex_unlock(¤t->perf_event_mutex);
- /*
- * Precalculate sample_data sizes
- */
- perf_event__header_size(event);
- perf_event__id_header_size(event);
-
/*
* Drop the reference on the group_event after placing the
* new event on the sibling_list. This ensures destruction
fd_install(event_fd, event_file);
return event_fd;
+err_locked:
+ if (move_group)
+ mutex_unlock(&gctx->mutex);
+ mutex_unlock(&ctx->mutex);
+/* err_file: */
+ fput(event_file);
err_context:
perf_unpin_context(ctx);
put_ctx(ctx);
projects / karo-tx-linux.git / blobdiff