[PATCH v5 06/17] perf mem: Add statistics for peer snooping

Leo Yan
2022-06-04T04:29:27Z

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
peer related metrics when flag PERF_MEM_SNOOPX_PEER is set.

So three new metrics are introduced: 'lcl_peer' is for local cache
access, the metric 'rmt_peer' is for remote access (includes remote DRAM
and any caches in remote node), and the metric 'tot_peer' is accounting
the sum value of 'lcl_peer' and 'rmt_peer'.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Acked-by: Ian Rogers <irogers@google.com>
Tested-by: Ali Saidi <alisaidi@amazon.com>
Reviewed-by: Ali Saidi <alisaidi@amazon.com>
---
tools/perf/util/mem-events.c | 28 +++++++++++++++++++++++++---
tools/perf/util/mem-events.h | 3 +++
2 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/mem-events.c b/tools/perf/util/mem-events.c
index 5dca1882c284..764883183519 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;
/*
@@ -544,6 +545,12 @@ do { \
stats->tot_hitm++; \
} while (0)

+#define PEER_INC(__f) \
+do { \
+ stats->__f++; \
+ stats->tot_peer++; \
+} while (0)
+
#define P(a, b) PERF_MEM_##a##_##b

stats->nr_entries++;
@@ -567,12 +574,20 @@ 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))
+ PEER_INC(lcl_peer);
+ }
if (lvl & P(LVL, L3 )) {
if (snoop & P(SNOOP, HITM))
HITM_INC(lcl_hitm);
else
stats->ld_llchit++;
+
+ if (snoopx & P(SNOOPX, PEER))
+ PEER_INC(lcl_peer);
}

if (lvl & P(LVL, LOC_RAM)) {
@@ -597,10 +612,14 @@ 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++;
+ PEER_INC(rmt_peer);
+ }
}

if ((lvl & P(LVL, MISS)))
@@ -664,6 +683,9 @@ void c2c_add_stats(struct c2c_stats *stats, struct c2c_stats *add)
stats->lcl_hitm += add->lcl_hitm;
stats->rmt_hitm += add->rmt_hitm;
stats->tot_hitm += add->tot_hitm;
+ stats->lcl_peer += add->lcl_peer;
+ stats->rmt_peer += add->rmt_peer;
+ stats->tot_peer += add->tot_peer;
stats->rmt_hit += add->rmt_hit;
stats->lcl_dram += add->lcl_dram;
stats->rmt_dram += add->rmt_dram;
diff --git a/tools/perf/util/mem-events.h b/tools/perf/util/mem-events.h
index 8a8b568baeee..12372309d60e 100644
--- a/tools/perf/util/mem-events.h
+++ b/tools/perf/util/mem-events.h
@@ -78,6 +78,9 @@ struct c2c_stats {
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 */
+ u32 lcl_peer; /* count of loads with local peer cache */
+ u32 rmt_peer; /* count of loads with remote peer cache */
+ u32 tot_peer; /* count of loads with local and remote peer cache */
u32 rmt_hit; /* count of loads with remote hit clean; */
u32 lcl_dram; /* count of loads miss to local DRAM */
u32 rmt_dram; /* count of loads miss to remote DRAM */
--
2.25.1