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authorLinus Torvalds <torvalds@linux-foundation.org>2013-12-17 12:35:05 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-12-17 12:35:05 -0800
commit1070d5ac193af55fd335ef2aacaf03c5fc4ee461 (patch)
treedc59593663b2c34f84444926ccf0cb93c81149e3
parent0eda4020ae53cc057a04ccc802a67f2a5336f8ef (diff)
parentcf30d52e2d11523c42048ab89ed4215b5021526a (diff)
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fix from Ingo Molnar: "An x86/intel event constraint fix" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86: Fix constraint table end marker bug
-rw-r--r--arch/x86/kernel/cpu/perf_event.h15
1 files changed, 12 insertions, 3 deletions
diff --git a/arch/x86/kernel/cpu/perf_event.h b/arch/x86/kernel/cpu/perf_event.h
index fd00bb29425..c1a861829d8 100644
--- a/arch/x86/kernel/cpu/perf_event.h
+++ b/arch/x86/kernel/cpu/perf_event.h
@@ -262,11 +262,20 @@ struct cpu_hw_events {
__EVENT_CONSTRAINT(c, n, INTEL_ARCH_EVENT_MASK, \
HWEIGHT(n), 0, PERF_X86_EVENT_PEBS_ST_HSW)
-#define EVENT_CONSTRAINT_END \
- EVENT_CONSTRAINT(0, 0, 0)
+/*
+ * We define the end marker as having a weight of -1
+ * to enable blacklisting of events using a counter bitmask
+ * of zero and thus a weight of zero.
+ * The end marker has a weight that cannot possibly be
+ * obtained from counting the bits in the bitmask.
+ */
+#define EVENT_CONSTRAINT_END { .weight = -1 }
+/*
+ * Check for end marker with weight == -1
+ */
#define for_each_event_constraint(e, c) \
- for ((e) = (c); (e)->weight; (e)++)
+ for ((e) = (c); (e)->weight != -1; (e)++)
/*
* Extra registers for specific events.