2015-12-09 16:32:29

by Vince Weaver

[permalink] [raw]
Subject: [patch] perf: remove l1-dcache-stores event for AMD


This is a long standing bug with the l1-dcache-stores generic event on
AMD machines. My perf_event testsuite has been complaining about this
for years and I'm finally getting around to trying to get it fixed.

The data_cache_refills:system event does not make sense for l1-dcache-stores.
Maybe this was a typo and it was meant to be for l1-dcache-store-misses?

In any case, the values returned are nowhere near correct for l1-dcache-stores
and in fact the umask values for the event have completely changed with
fam15h so it makes even less sense than ever. So just remove it.

Signed-off-by: Vince Weaver <[email protected]>

diff --git a/arch/x86/kernel/cpu/perf_event_amd.c b/arch/x86/kernel/cpu/perf_event_amd.c
index 1cee5d2..05e76bf 100644
--- a/arch/x86/kernel/cpu/perf_event_amd.c
+++ b/arch/x86/kernel/cpu/perf_event_amd.c
@@ -18,7 +18,7 @@ static __initconst const u64 amd_hw_cache_event_ids
[ C(RESULT_MISS) ] = 0x0141, /* Data Cache Misses */
},
[ C(OP_WRITE) ] = {
- [ C(RESULT_ACCESS) ] = 0x0142, /* Data Cache Refills :system */
+ [ C(RESULT_ACCESS) ] = 0,
[ C(RESULT_MISS) ] = 0,
},
[ C(OP_PREFETCH) ] = {