diff options
| -rw-r--r-- | include/linux/perf_event.h | 6 | ||||
| -rw-r--r-- | kernel/perf_event.c | 75 |
2 files changed, 80 insertions, 1 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index df9d964c15f..fa151d49a2e 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -744,6 +744,12 @@ extern int hw_perf_group_sched_in(struct perf_event *group_leader, struct perf_cpu_context *cpuctx, struct perf_event_context *ctx, int cpu); extern void perf_event_update_userpage(struct perf_event *event); +extern int perf_event_release_kernel(struct perf_event *event); +extern struct perf_event * +perf_event_create_kernel_counter(struct perf_event_attr *attr, + int cpu, + pid_t pid); +extern u64 perf_event_read_value(struct perf_event *event); struct perf_sample_data { u64 type; diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 12b5ec39bf9..02d4ff041b0 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -1725,6 +1725,26 @@ static int perf_release(struct inode *inode, struct file *file) return 0; } +int perf_event_release_kernel(struct perf_event *event) +{ + struct perf_event_context *ctx = event->ctx; + + WARN_ON_ONCE(ctx->parent_ctx); + mutex_lock(&ctx->mutex); + perf_event_remove_from_context(event); + mutex_unlock(&ctx->mutex); + + mutex_lock(&event->owner->perf_event_mutex); + list_del_init(&event->owner_entry); + mutex_unlock(&event->owner->perf_event_mutex); + put_task_struct(event->owner); + + free_event(event); + + return 0; +} +EXPORT_SYMBOL_GPL(perf_event_release_kernel); + static int perf_event_read_size(struct perf_event *event) { int entry = sizeof(u64); /* value */ @@ -1750,7 +1770,7 @@ static int perf_event_read_size(struct perf_event *event) return size; } -static u64 perf_event_read_value(struct perf_event *event) +u64 perf_event_read_value(struct perf_event *event) { struct perf_event *child; u64 total = 0; @@ -1761,6 +1781,7 @@ static u64 perf_event_read_value(struct perf_event *event) return total; } +EXPORT_SYMBOL_GPL(perf_event_read_value); static int perf_event_read_entry(struct perf_event *event, u64 read_format, char __user *buf) @@ -4638,6 +4659,58 @@ err_put_context: return err; } +/** + * perf_event_create_kernel_counter + * + * @attr: attributes of the counter to create + * @cpu: cpu in which the counter is bound + * @pid: task to profile + */ +struct perf_event * +perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, + pid_t pid) +{ + struct perf_event *event; + struct perf_event_context *ctx; + int err; + + /* + * Get the target context (task or percpu): + */ + + ctx = find_get_context(pid, cpu); + if (IS_ERR(ctx)) + return NULL ; + + event = perf_event_alloc(attr, cpu, ctx, NULL, + NULL, GFP_KERNEL); + err = PTR_ERR(event); + if (IS_ERR(event)) + goto err_put_context; + + event->filp = NULL; + WARN_ON_ONCE(ctx->parent_ctx); + mutex_lock(&ctx->mutex); + perf_install_in_context(ctx, event, cpu); + ++ctx->generation; + mutex_unlock(&ctx->mutex); + + event->owner = current; + get_task_struct(current); + mutex_lock(¤t->perf_event_mutex); + list_add_tail(&event->owner_entry, ¤t->perf_event_list); + mutex_unlock(¤t->perf_event_mutex); + + return event; + +err_put_context: + if (err < 0) + put_ctx(ctx); + + return NULL; +} +EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter); + /* * inherit a event from parent task to child task: */ |