Skip to content
Snippets Groups Projects
Commit d4bdb0be authored by Stephane Eranian's avatar Stephane Eranian Committed by Peter Zijlstra
Browse files

perf/x86/intel/ds: Fix precise store latency handling


With the existing code in store_latency_data(), the memory operation (mem_op)
returned to the user is always OP_LOAD where in fact, it should be OP_STORE.
This comes from the fact that the function is simply grabbing the information
from a data source map which covers only load accesses. Intel 12th gen CPU
offers precise store sampling that captures both the data source and latency.
Therefore it can use the data source mapping table but must override the
memory operation to reflect stores instead of loads.

Fixes: 61b985e3 ("perf/x86/intel: Add perf core PMU support for Sapphire Rapids")
Signed-off-by: default avatarStephane Eranian <eranian@google.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220818054613.1548130-1-eranian@google.com
parent 7d359886
No related branches found
No related tags found
No related merge requests found
...@@ -291,6 +291,7 @@ static u64 load_latency_data(struct perf_event *event, u64 status) ...@@ -291,6 +291,7 @@ static u64 load_latency_data(struct perf_event *event, u64 status)
static u64 store_latency_data(struct perf_event *event, u64 status) static u64 store_latency_data(struct perf_event *event, u64 status)
{ {
union intel_x86_pebs_dse dse; union intel_x86_pebs_dse dse;
union perf_mem_data_src src;
u64 val; u64 val;
dse.val = status; dse.val = status;
...@@ -304,7 +305,14 @@ static u64 store_latency_data(struct perf_event *event, u64 status) ...@@ -304,7 +305,14 @@ static u64 store_latency_data(struct perf_event *event, u64 status)
val |= P(BLK, NA); val |= P(BLK, NA);
return val; /*
* the pebs_data_source table is only for loads
* so override the mem_op to say STORE instead
*/
src.val = val;
src.mem_op = P(OP,STORE);
return src.val;
} }
struct pebs_record_core { struct pebs_record_core {
......
0% Loading or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment