On 01/07/2022 13:07, carsten.haitzler@foss.arm.com wrote:
From: "Carsten Haitzler (Rasterman)" raster@rasterman.com
Add a script to drive the threaded memcpy test that gathers data so it passes a minimum bar for amount and quality of content that we extract from the kernel's perf support.
On this one I get a failure about 1/50 times on N1SDP (I ran it about 150 times and saw 3 failures so it's quite consistent). Usually it records about a 1.4MB file with one aux record. But when it fails the file is only 20K and has one small aux record:
0 0 0x1a10 [0x30]: PERF_RECORD_AUXTRACE size: 0x1820 offset: 0 ref: 0x1c23126d7ff3d2ab idx: 3 tid: 682799 cpu: 3
Nothing was dropped, and the load on the system wasn't any different to when it passes. So I'm not sure if this is a real coresight bug or that the test is flaky. There was a bug in SPE before where threads weren't followed after forking, but only very rarely. It feels a bit like that.
It could also be some contention issue because 10 threads are launched but the machine only has 4 cores.
The failure message from the test looks like this:
77: CoreSight / Memcpy 16k 10 Threads : --- start --- Couldn't synthesize bpf events. [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.012 MB ./perf-memcpy_thread-16k_10.data ] Sanity check number of ASYNC is too low (3 < 10) ---- end ---- CoreSight / Memcpy 16k 10 Threads: FAILED!
I didn't see this issue on any of the other tests. Sometimes very small files were made if I loaded the system, but the tests still passed.
Thanks James
Signed-off-by: Carsten Haitzler carsten.haitzler@arm.com
.../shell/coresight/memcpy_thread_16k_10.sh | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) create mode 100755 tools/perf/tests/shell/coresight/memcpy_thread_16k_10.sh
diff --git a/tools/perf/tests/shell/coresight/memcpy_thread_16k_10.sh b/tools/perf/tests/shell/coresight/memcpy_thread_16k_10.sh new file mode 100755 index 000000000000..d21ba8545938 --- /dev/null +++ b/tools/perf/tests/shell/coresight/memcpy_thread_16k_10.sh @@ -0,0 +1,18 @@ +#!/bin/sh -e +# CoreSight / Memcpy 16k 10 Threads
+# SPDX-License-Identifier: GPL-2.0 +# Carsten Haitzler carsten.haitzler@arm.com, 2021
+TEST="memcpy_thread" +. $(dirname $0)/../lib/coresight.sh +ARGS="16 10 1" +DATV="16k_10" +DATA="$DATD/perf-$TEST-$DATV.data"
+perf record $PERFRECOPT -o "$DATA" "$BIN" $ARGS
+perf_dump_aux_verify "$DATA" 10 10 10
+err=$? +exit $err