This is a note to let you know that I've just added the patch titled
perf test: Remove atomics from test_loop to avoid test failures
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
perf-test-remove-atomics-from-test_loop-to-avoid-tes.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit ac5a1760cbd37ca74bc1e3082c272b9ef277a551
Author: Nick Forrington <nick.forrington@xxxxxxx>
Date: Thu Nov 2 16:22:24 2023 +0000
perf test: Remove atomics from test_loop to avoid test failures
[ Upstream commit 72b4ca7e993e94f09bcf6d19fc385a2e8060c71f ]
The current use of atomics can lead to test failures, as tests (such as
tests/shell/record.sh) search for samples with "test_loop" as the
top-most stack frame, but find frames related to the atomic operation
(e.g. __aarch64_ldadd4_relax).
This change simply removes the "count" variable, as it is not necessary.
Fixes: 1962ab6f6e0b39e4 ("perf test workload thloop: Make count increments atomic")
Reviewed-by: James Clark <james.clark@xxxxxxx>
Signed-off-by: Nick Forrington <nick.forrington@xxxxxxx>
Acked-by: Leo Yan <leo.yan@xxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Ian Rogers <irogers@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20231102162225.50028-1-nick.forrington@xxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/tools/perf/tests/workloads/thloop.c b/tools/perf/tests/workloads/thloop.c
index af05269c2eb8..457b29f91c3e 100644
--- a/tools/perf/tests/workloads/thloop.c
+++ b/tools/perf/tests/workloads/thloop.c
@@ -7,7 +7,6 @@
#include "../tests.h"
static volatile sig_atomic_t done;
-static volatile unsigned count;
/* We want to check this symbol in perf report */
noinline void test_loop(void);
@@ -19,8 +18,7 @@ static void sighandler(int sig __maybe_unused)
noinline void test_loop(void)
{
- while (!done)
- __atomic_fetch_add(&count, 1, __ATOMIC_RELAXED);
+ while (!done);
}
static void *thfunc(void *arg)
