perf, x86: Use weight instead of cmask in for_each_event_constraint()

There may exist constraints with a cmask set to zero. In this case
for_each_event_constraint() will not work properly. Now weight is used
instead of the cmask for loop exit detection. Weight is always a value
other than zero since the default contains the HWEIGHT from the
counter mask and in other cases a value of zero does not fit too.

This is in preparation of ibs event constraints that wont have a
cmask.

Signed-off-by: Robert Richter <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
LKML-Reference: <1271190201[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 4e218d7ac8526a735cfb9605909fd54e5b7262c9..4a3f1f2b9b91c75e5c08e6c3a5f1b38187227b52 100644 (file)
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -170,7 +170,7 @@ struct cpu_hw_events {
        EVENT_CONSTRAINT(0, 0, 0)
 
 #define for_each_event_constraint(e, c)        \
-       for ((e) = (c); (e)->cmask; (e)++)
+       for ((e) = (c); (e)->weight; (e)++)
 
 union perf_capabilities {
        struct {