[PATCH v2 1/2] perf tools: Fix record failure when mixed with ARM SPE event

Wei Li liwei391 at huawei.com
Fri Jul 24 03:11:10 EDT 2020


When recording with cache-misses and arm_spe_x event, i found that
it will just fail without showing any error info if i put cache-misses
after 'arm_spe_x' event.

[root at localhost 0620]# perf record -e cache-misses -e \
arm_spe_0/ts_enable=1,pct_enable=1,pa_enable=1,load_filter=1,\
jitter=1,store_filter=1,min_latency=0/ sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.067 MB perf.data ]
[root at localhost 0620]# perf record -e \
arm_spe_0/ts_enable=1,pct_enable=1,pa_enable=1,load_filter=1,jitter=1,\
store_filter=1,min_latency=0/ -e cache-misses sleep 1
[root at localhost 0620]#

The current code can only work if the only event to be traced is an
'arm_spe_x', or if it is the last event to be specified. Otherwise the
last event type will be checked against all the arm_spe_pmus[i]->types,
none will match and an out of bound 'i' index will be used in
arm_spe_recording_init().

We don't support concurrent multiple arm_spe_x events currently, that
is checked in arm_spe_recording_options(), and it will show the relevant
info. So add the check and record of the first found 'arm_spe_pmu' to
fix this issue here.

Fixes: ffd3d18c20b8d ("perf tools: Add ARM Statistical Profiling Extensions (SPE) support")
Signed-off-by: Wei Li <liwei391 at huawei.com>
---
 tools/perf/arch/arm/util/auxtrace.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/perf/arch/arm/util/auxtrace.c b/tools/perf/arch/arm/util/auxtrace.c
index 0a6e75b8777a..28a5d0c18b1d 100644
--- a/tools/perf/arch/arm/util/auxtrace.c
+++ b/tools/perf/arch/arm/util/auxtrace.c
@@ -56,7 +56,7 @@ struct auxtrace_record
 	struct perf_pmu	*cs_etm_pmu;
 	struct evsel *evsel;
 	bool found_etm = false;
-	bool found_spe = false;
+	struct perf_pmu *found_spe = NULL;
 	static struct perf_pmu **arm_spe_pmus = NULL;
 	static int nr_spes = 0;
 	int i = 0;
@@ -74,12 +74,12 @@ struct auxtrace_record
 		    evsel->core.attr.type == cs_etm_pmu->type)
 			found_etm = true;
 
-		if (!nr_spes)
+		if (!nr_spes || found_spe)
 			continue;
 
 		for (i = 0; i < nr_spes; i++) {
 			if (evsel->core.attr.type == arm_spe_pmus[i]->type) {
-				found_spe = true;
+				found_spe = arm_spe_pmus[i];
 				break;
 			}
 		}
@@ -96,7 +96,7 @@ struct auxtrace_record
 
 #if defined(__aarch64__)
 	if (found_spe)
-		return arm_spe_recording_init(err, arm_spe_pmus[i]);
+		return arm_spe_recording_init(err, found_spe);
 #endif
 
 	/*
-- 
2.17.1




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