6.1-stable review patch. If anyone has any objections, please let me know.
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From: Namhyung Kim namhyung@kernel.org
[ Upstream commit 39281709a6e2301ac4c6ac7015c7793392ca2dfe ]
The sqrtloop creates a child process to run an infinite loop calling sqrt() with rand(). This is needed for ARM SPE fork test.
$ perf test -w sqrtloop
It can take an optional argument to specify how long it will run in seconds (default: 1).
Committer notes:
Explicitely ignored the sqrt() return to fix the build on systems where the compiler complains it isn't being used.
And added a sqrtloop specific CFLAGS to disable optimizations to make this a bit more robust wrt dead code elimination.
Doing that a -U_FORTIFY_SOURCE needs to be added, as -O0 is incompatible with it.
Signed-off-by: Namhyung Kim namhyung@kernel.org Cc: Adrian Hunter adrian.hunter@intel.com Cc: Athira Jajeev atrajeev@linux.vnet.ibm.com Cc: German Gomez german.gomez@arm.com Cc: Ian Rogers irogers@google.com Cc: Ingo Molnar mingo@kernel.org Cc: James Clark james.clark@arm.com Cc: Jiri Olsa jolsa@kernel.org Cc: Leo Yan leo.yan@linaro.org Cc: Peter Zijlstra peterz@infradead.org Cc: Zhengjun Xing zhengjun.xing@linux.intel.com Link: https://lore.kernel.org/r/20221116233854.1596378-8-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Stable-dep-of: 256ef072b384 ("perf tests: Make "test data symbol" more robust on Neoverse N1") Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/tests/builtin-test.c | 1 + tools/perf/tests/tests.h | 1 + tools/perf/tests/workloads/Build | 2 ++ tools/perf/tests/workloads/sqrtloop.c | 45 +++++++++++++++++++++++++++ 4 files changed, 49 insertions(+) create mode 100644 tools/perf/tests/workloads/sqrtloop.c
diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c index 0ed5ac452f6ee..9acb7a93eeb97 100644 --- a/tools/perf/tests/builtin-test.c +++ b/tools/perf/tests/builtin-test.c @@ -122,6 +122,7 @@ static struct test_workload *workloads[] = { &workload__noploop, &workload__thloop, &workload__leafloop, + &workload__sqrtloop, };
static int num_subtests(const struct test_suite *t) diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h index 86804dd6452b7..18c40319e67c7 100644 --- a/tools/perf/tests/tests.h +++ b/tools/perf/tests/tests.h @@ -203,5 +203,6 @@ struct test_workload workload__##work = { \ DECLARE_WORKLOAD(noploop); DECLARE_WORKLOAD(thloop); DECLARE_WORKLOAD(leafloop); +DECLARE_WORKLOAD(sqrtloop);
#endif /* TESTS_H */ diff --git a/tools/perf/tests/workloads/Build b/tools/perf/tests/workloads/Build index 03dc675a4a7c8..2312a338f01c0 100644 --- a/tools/perf/tests/workloads/Build +++ b/tools/perf/tests/workloads/Build @@ -3,5 +3,7 @@ perf-y += noploop.o perf-y += thloop.o perf-y += leafloop.o +perf-y += sqrtloop.o
+CFLAGS_sqrtloop.o = -g -O0 -fno-inline -U_FORTIFY_SOURCE CFLAGS_leafloop.o = -g -O0 -fno-inline -fno-omit-frame-pointer -U_FORTIFY_SOURCE diff --git a/tools/perf/tests/workloads/sqrtloop.c b/tools/perf/tests/workloads/sqrtloop.c new file mode 100644 index 0000000000000..ccc94c6a6676a --- /dev/null +++ b/tools/perf/tests/workloads/sqrtloop.c @@ -0,0 +1,45 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include <math.h> +#include <signal.h> +#include <stdlib.h> +#include <unistd.h> +#include <linux/compiler.h> +#include <sys/wait.h> +#include "../tests.h" + +static volatile sig_atomic_t done; + +static void sighandler(int sig __maybe_unused) +{ + done = 1; +} + +static int __sqrtloop(int sec) +{ + signal(SIGALRM, sighandler); + alarm(sec); + + while (!done) + (void)sqrt(rand()); + return 0; +} + +static int sqrtloop(int argc, const char **argv) +{ + int sec = 1; + + if (argc > 0) + sec = atoi(argv[0]); + + switch (fork()) { + case 0: + return __sqrtloop(sec); + case -1: + return -1; + default: + wait(NULL); + } + return 0; +} + +DEFINE_WORKLOAD(sqrtloop);