perf/x86/intel: Mark MEM_LOAD_UOPS_MISS_RETIRED as precise on SNB

On Intel SNB (SNB, SNB-EP), the event MEM_LOAD_UOPS_MISS_RETIRED
supports PEBS. It was missing for the SNB PEBS event constraint
table thereby preventing any measurement with PEBS for it.

This patch adds the event to the PEBS table for SNB.

WARNING: it should be noted that this event like a few others
are subject to the erratum BT241 for Xeon E5 (SNB-EP). As such,
the event may undercount when used with PEBS unless the
workaround is implemented. But without this patch and just the
workaround, the kernel would not allow precise sampling on this
event. BT241 is documented in:

  http://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/xeon-e5-family-spec-update.pdf

Signed-off-by: Stephane Eranian <eranian@google.com>
Cc: peterz@infradead.org
Cc: ak@linux.intel.com
Cc: zheng.z.yan@intel.com
Link: http://lkml.kernel.org/r/20130913201646.GA23981@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index 3065c57a63c19873e07d18e13122f04704e2de96..4ab70acd3a8dcdfb95f041fcdabae17aa8434be7 100644 (file)
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -558,6 +558,7 @@ struct event_constraint intel_snb_pebs_event_constraints[] = {
        INTEL_EVENT_CONSTRAINT(0xd0, 0xf),    /* MEM_UOP_RETIRED.* */
        INTEL_EVENT_CONSTRAINT(0xd1, 0xf),    /* MEM_LOAD_UOPS_RETIRED.* */
        INTEL_EVENT_CONSTRAINT(0xd2, 0xf),    /* MEM_LOAD_UOPS_LLC_HIT_RETIRED.* */
+       INTEL_EVENT_CONSTRAINT(0xd3, 0xf),    /* MEM_LOAD_UOPS_LLC_MISS_RETIRED.* */
        INTEL_UEVENT_CONSTRAINT(0x02d4, 0xf), /* MEM_LOAD_UOPS_MISC_RETIRED.LLC_MISS */
        EVENT_CONSTRAINT_END
 };