[PATCH v3 04/11] perf mem: Add statistics for peer snooping

From: Leo Yan
Date: Wed May 18 2022 - 01:58:18 EST


Since the flag PERF_MEM_SNOOPX_PEER is added to support cache snooping
from peer cache line, it can come from a peer core, a peer cluster, or
a remote NUMA node.

This patch adds statistics for the flag PERF_MEM_SNOOPX_PEER. Note, we
take PERF_MEM_SNOOPX_PEER as an affiliated info, it needs to cooperate
with cache level statistics. Therefore, we account the load operations
for both the cache level's metrics (e.g. ld_l2hit, ld_llchit, etc.) and
the metric 'ld_peer' when flag PERF_MEM_SNOOPX_PEER is set.

Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
Tested-by: Ali Saidi <alisaidi@xxxxxxxxxx>
---
tools/perf/util/mem-events.c | 22 +++++++++++++++++++---
tools/perf/util/mem-events.h | 1 +
2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/mem-events.c b/tools/perf/util/mem-events.c
index 5dca1882c284..9de0eb3a1200 100644
--- a/tools/perf/util/mem-events.c
+++ b/tools/perf/util/mem-events.c
@@ -525,6 +525,7 @@ int c2c_decode_stats(struct c2c_stats *stats, struct mem_info *mi)
u64 op = data_src->mem_op;
u64 lvl = data_src->mem_lvl;
u64 snoop = data_src->mem_snoop;
+ u64 snoopx = data_src->mem_snoopx;
u64 lock = data_src->mem_lock;
u64 blk = data_src->mem_blk;
/*
@@ -567,18 +568,28 @@ do { \
if (lvl & P(LVL, IO)) stats->ld_io++;
if (lvl & P(LVL, LFB)) stats->ld_fbhit++;
if (lvl & P(LVL, L1 )) stats->ld_l1hit++;
- if (lvl & P(LVL, L2 )) stats->ld_l2hit++;
+ if (lvl & P(LVL, L2)) {
+ stats->ld_l2hit++;
+
+ if (snoopx & P(SNOOPX, PEER))
+ stats->ld_peer++;
+ }
if (lvl & P(LVL, L3 )) {
if (snoop & P(SNOOP, HITM))
HITM_INC(lcl_hitm);
else
stats->ld_llchit++;
+
+ if (snoopx & P(SNOOPX, PEER))
+ stats->ld_peer++;
}

if (lvl & P(LVL, LOC_RAM)) {
stats->lcl_dram++;
if (snoop & P(SNOOP, HIT))
stats->ld_shared++;
+ else if (snoopx & P(SNOOPX, PEER))
+ stats->ld_peer++;
else
stats->ld_excl++;
}
@@ -597,10 +608,14 @@ do { \
if ((lvl & P(LVL, REM_CCE1)) ||
(lvl & P(LVL, REM_CCE2)) ||
mrem) {
- if (snoop & P(SNOOP, HIT))
+ if (snoop & P(SNOOP, HIT)) {
stats->rmt_hit++;
- else if (snoop & P(SNOOP, HITM))
+ } else if (snoop & P(SNOOP, HITM)) {
HITM_INC(rmt_hitm);
+ } else if (snoopx & P(SNOOPX, PEER)) {
+ stats->rmt_hit++;
+ stats->ld_peer++;
+ }
}

if ((lvl & P(LVL, MISS)))
@@ -661,6 +676,7 @@ void c2c_add_stats(struct c2c_stats *stats, struct c2c_stats *add)
stats->ld_l1hit += add->ld_l1hit;
stats->ld_l2hit += add->ld_l2hit;
stats->ld_llchit += add->ld_llchit;
+ stats->ld_peer += add->ld_peer;
stats->lcl_hitm += add->lcl_hitm;
stats->rmt_hitm += add->rmt_hitm;
stats->tot_hitm += add->tot_hitm;
diff --git a/tools/perf/util/mem-events.h b/tools/perf/util/mem-events.h
index 8a8b568baeee..4879b841c841 100644
--- a/tools/perf/util/mem-events.h
+++ b/tools/perf/util/mem-events.h
@@ -75,6 +75,7 @@ struct c2c_stats {
u32 ld_l1hit; /* count of loads that hit L1D */
u32 ld_l2hit; /* count of loads that hit L2D */
u32 ld_llchit; /* count of loads that hit LLC */
+ u32 ld_peer; /* count of loads that hit peer core or cluster cache */
u32 lcl_hitm; /* count of loads with local HITM */
u32 rmt_hitm; /* count of loads with remote HITM */
u32 tot_hitm; /* count of loads with local and remote HITM */
--
2.25.1