Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

 * Do annotation using /proc/kcore and /proc/kallsyms, removing the
   need for a vmlinux file kernel assembly annotation. This also improves
   this use case because vmlinux has just the initial kernel image, not
   what is actually in use after various code patchings by things like
   alternatives, etc. From Adrian Hunter.

 * Add various improvements and fixes to the "vmlinux matches kallsyms"
   'perf test' entry, related to the /proc/kcore annotation feature.

 * Add --initial-delay option to 'perf stat' to skip measuring for
   the startup phase, from Andi Kleen.

 * Add perf kvm stat live mode that combines aspects of 'perf kvm stat' record
   and report, from David Ahern.

 * Add option to analyze specific VM in perf kvm stat report, from David Ahern.

 * Do not require /lib/modules/* on a guest, fix from Jason Wessel.

 * Group leader sampling, that allows just one event in a group to sample while
   the other events have just its values read, from Jiri Olsa.

 * Add support for a new modifier "D", which requests that the event, or group
   of events, be pinned to the PMU, from Michael Ellerman.

 * Fix segmentation fault on the gtk browser, from Namhyung Kim.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 11 insertions, 1 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 916cf1f593b4..e82e70025d42 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3568,6 +3568,15 @@ static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	case PERF_EVENT_IOC_PERIOD:
 		return perf_event_period(event, (u64 __user *)arg);
 
+	case PERF_EVENT_IOC_ID:
+	{
+		u64 id = primary_event_id(event);
+
+		if (copy_to_user((void __user *)arg, &id, sizeof(id)))
+			return -EFAULT;
+		return 0;
+	}
+
 	case PERF_EVENT_IOC_SET_OUTPUT:
 	{
 		int ret;
@@ -4379,7 +4388,8 @@ static void perf_output_read_group(struct perf_output_handle *handle,
 	list_for_each_entry(sub, &leader->sibling_list, group_entry) {
 		n = 0;
 
-		if (sub != event)
+		if ((sub != event) &&
+		    (sub->state == PERF_EVENT_STATE_ACTIVE))
 			sub->pmu->read(sub);
 
 		values[n++] = perf_event_count(sub);