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* [PATCH] Perf stat: Fix the ratio comments of cache miss-events
@ 2020-02-13  8:55 Lin Feng
  2020-02-17  8:07 ` Qi Liu
  0 siblings, 1 reply; 2+ messages in thread
From: Lin Feng @ 2020-02-13  8:55 UTC (permalink / raw)
  To: peterz, mingo, acme, ak, liuqi115; +Cc: linux-kernel, Lin Feng

Perf stat displays miss ratio of L1-dcache, L1-icache, dTLB cache,
iTLB cache and LL-cache, while the comments for them seem a bit
misleading. Take L1-dcache for example, its miss ratio
is caculated as "L1-dcache-load-misses/L1-dcache-loads". So "of all
L1-dcache hits" is unsuitable to describe it, and "of all L1-dcache
accesses/references" seems better.

 285,132,521 cache-misses            #   53.696 % of all cache refs     [83.34%]
 531,015,219 cache-references                                           [83.20%]
 220,465,183 LLC-load-misses         #   72.33% of all LL-cache miss    [83.44%]
                                                                  ^^^^
 304,787,745 LLC-loads                                                  [66.60%]

There is an old patch here https://lkml.org/lkml/2019/11/16/37, but
seems not upstreamed yet. This patch follows suggestions by Arnaldo.
But one difference is using "refs" to follow the convention because
there is comment also for cache-misses event which uses
"of all cache refs".
The comments of L1-icache, dTLB cache, iTLB cache and LL-cache are
fixed in the same way.

P.S. Liu and Andi if you don't mind this patch adds your Reviewed-by
and Signed-off-by, thanks.

Reviewed-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Qi Liu <liuqi115@hisilicon.com>
Signed-off-by: Lin Feng <linf@wangsu.com>
---
 tools/perf/util/stat-shadow.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/tools/perf/util/stat-shadow.c b/tools/perf/util/stat-shadow.c
index 2c41d47f6f83..070e9749e934 100644
--- a/tools/perf/util/stat-shadow.c
+++ b/tools/perf/util/stat-shadow.c
@@ -506,7 +506,7 @@ static void print_l1_dcache_misses(struct perf_stat_config *config,
 
 	color = get_ratio_color(GRC_CACHE_MISSES, ratio);
 
-	out->print_metric(config, out->ctx, color, "%7.2f%%", "of all L1-dcache hits", ratio);
+	out->print_metric(config, out->ctx, color, "%7.2f%%", "of all L1-dcache refs", ratio);
 }
 
 static void print_l1_icache_misses(struct perf_stat_config *config,
@@ -527,7 +527,7 @@ static void print_l1_icache_misses(struct perf_stat_config *config,
 		ratio = avg / total * 100.0;
 
 	color = get_ratio_color(GRC_CACHE_MISSES, ratio);
-	out->print_metric(config, out->ctx, color, "%7.2f%%", "of all L1-icache hits", ratio);
+	out->print_metric(config, out->ctx, color, "%7.2f%%", "of all L1-icache refs", ratio);
 }
 
 static void print_dtlb_cache_misses(struct perf_stat_config *config,
@@ -547,7 +547,7 @@ static void print_dtlb_cache_misses(struct perf_stat_config *config,
 		ratio = avg / total * 100.0;
 
 	color = get_ratio_color(GRC_CACHE_MISSES, ratio);
-	out->print_metric(config, out->ctx, color, "%7.2f%%", "of all dTLB cache hits", ratio);
+	out->print_metric(config, out->ctx, color, "%7.2f%%", "of all dTLB cache refs", ratio);
 }
 
 static void print_itlb_cache_misses(struct perf_stat_config *config,
@@ -567,7 +567,7 @@ static void print_itlb_cache_misses(struct perf_stat_config *config,
 		ratio = avg / total * 100.0;
 
 	color = get_ratio_color(GRC_CACHE_MISSES, ratio);
-	out->print_metric(config, out->ctx, color, "%7.2f%%", "of all iTLB cache hits", ratio);
+	out->print_metric(config, out->ctx, color, "%7.2f%%", "of all iTLB cache refs", ratio);
 }
 
 static void print_ll_cache_misses(struct perf_stat_config *config,
@@ -587,7 +587,7 @@ static void print_ll_cache_misses(struct perf_stat_config *config,
 		ratio = avg / total * 100.0;
 
 	color = get_ratio_color(GRC_CACHE_MISSES, ratio);
-	out->print_metric(config, out->ctx, color, "%7.2f%%", "of all LL-cache hits", ratio);
+	out->print_metric(config, out->ctx, color, "%7.2f%%", "of all LL-cache refs", ratio);
 }
 
 /*
@@ -872,7 +872,7 @@ void perf_stat__print_shadow_stats(struct perf_stat_config *config,
 		if (runtime_stat_n(st, STAT_L1_DCACHE, ctx, cpu) != 0)
 			print_l1_dcache_misses(config, cpu, evsel, avg, out, st);
 		else
-			print_metric(config, ctxp, NULL, NULL, "of all L1-dcache hits", 0);
+			print_metric(config, ctxp, NULL, NULL, "of all L1-dcache refs", 0);
 	} else if (
 		evsel->core.attr.type == PERF_TYPE_HW_CACHE &&
 		evsel->core.attr.config ==  ( PERF_COUNT_HW_CACHE_L1I |
@@ -882,7 +882,7 @@ void perf_stat__print_shadow_stats(struct perf_stat_config *config,
 		if (runtime_stat_n(st, STAT_L1_ICACHE, ctx, cpu) != 0)
 			print_l1_icache_misses(config, cpu, evsel, avg, out, st);
 		else
-			print_metric(config, ctxp, NULL, NULL, "of all L1-icache hits", 0);
+			print_metric(config, ctxp, NULL, NULL, "of all L1-icache refs", 0);
 	} else if (
 		evsel->core.attr.type == PERF_TYPE_HW_CACHE &&
 		evsel->core.attr.config ==  ( PERF_COUNT_HW_CACHE_DTLB |
@@ -892,7 +892,7 @@ void perf_stat__print_shadow_stats(struct perf_stat_config *config,
 		if (runtime_stat_n(st, STAT_DTLB_CACHE, ctx, cpu) != 0)
 			print_dtlb_cache_misses(config, cpu, evsel, avg, out, st);
 		else
-			print_metric(config, ctxp, NULL, NULL, "of all dTLB cache hits", 0);
+			print_metric(config, ctxp, NULL, NULL, "of all dTLB cache refs", 0);
 	} else if (
 		evsel->core.attr.type == PERF_TYPE_HW_CACHE &&
 		evsel->core.attr.config ==  ( PERF_COUNT_HW_CACHE_ITLB |
@@ -902,7 +902,7 @@ void perf_stat__print_shadow_stats(struct perf_stat_config *config,
 		if (runtime_stat_n(st, STAT_ITLB_CACHE, ctx, cpu) != 0)
 			print_itlb_cache_misses(config, cpu, evsel, avg, out, st);
 		else
-			print_metric(config, ctxp, NULL, NULL, "of all iTLB cache hits", 0);
+			print_metric(config, ctxp, NULL, NULL, "of all iTLB cache refs", 0);
 	} else if (
 		evsel->core.attr.type == PERF_TYPE_HW_CACHE &&
 		evsel->core.attr.config ==  ( PERF_COUNT_HW_CACHE_LL |
@@ -912,7 +912,7 @@ void perf_stat__print_shadow_stats(struct perf_stat_config *config,
 		if (runtime_stat_n(st, STAT_LL_CACHE, ctx, cpu) != 0)
 			print_ll_cache_misses(config, cpu, evsel, avg, out, st);
 		else
-			print_metric(config, ctxp, NULL, NULL, "of all LL-cache hits", 0);
+			print_metric(config, ctxp, NULL, NULL, "of all LL-cache refs", 0);
 	} else if (perf_evsel__match(evsel, HARDWARE, HW_CACHE_MISSES)) {
 		total = runtime_stat_avg(st, STAT_CACHEREFS, ctx, cpu);
 
-- 
2.20.1


^ permalink raw reply	[flat|nested] 2+ messages in thread
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2020-02-13  8:55 [PATCH] Perf stat: Fix the ratio comments of cache miss-events Lin Feng
2020-02-17  8:07 ` Qi Liu

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