perf/x86/cqm: Fix CQM handling of grouping events into a cache_group

[deliverable/linux.git] / arch / x86 / events / intel / cqm.c

diff --git a/arch/x86/events/intel/cqm.c b/arch/x86/events/intel/cqm.c
index 93cb412a55792fbc68f2460da7295c77098e4532..b0226f1912a21ed92d70bf6b438150cce16e80c2 100644 (file)
--- a/arch/x86/events/intel/cqm.c
+++ b/arch/x86/events/intel/cqm.c
@@ -281,9 +281,13 @@ static bool __match_event(struct perf_event *a, struct perf_event *b)
 
        /*
         * Events that target same task are placed into the same cache group.
+        * Mark it as a multi event group, so that we update ->count
+        * for every event rather than just the group leader later.
         */
-       if (a->hw.target == b->hw.target)
+       if (a->hw.target == b->hw.target) {
+               b->hw.is_group_event = true;
                return true;
+       }
 
        /*
         * Are we an inherited event?
@@ -849,6 +853,7 @@ static void intel_cqm_setup_event(struct perf_event *event,
        bool conflict = false;
        u32 rmid;
 
+       event->hw.is_group_event = false;
        list_for_each_entry(iter, &cache_groups, hw.cqm_groups_entry) {
                rmid = iter->hw.cqm_rmid;
 
@@ -940,7 +945,9 @@ static u64 intel_cqm_event_count(struct perf_event *event)
                return __perf_event_count(event);
 
        /*
-        * Only the group leader gets to report values. This stops us
+        * Only the group leader gets to report values except in case of
+        * multiple events in the same group, we still need to read the
+        * other events.This stops us
         * reporting duplicate values to userspace, and gives us a clear
         * rule for which task gets to report the values.
         *
@@ -948,7 +955,7 @@ static u64 intel_cqm_event_count(struct perf_event *event)
         * specific packages - we forfeit that ability when we create
         * task events.
         */
-       if (!cqm_group_leader(event))
+       if (!cqm_group_leader(event) && !event->hw.is_group_event)
                return 0;
 
        /*