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>
&workload__noploop,
&workload__thloop,
&workload__leafloop,
+ &workload__sqrtloop,
};
static int num_subtests(const struct test_suite *t)
DECLARE_WORKLOAD(noploop);
DECLARE_WORKLOAD(thloop);
DECLARE_WORKLOAD(leafloop);
+DECLARE_WORKLOAD(sqrtloop);
#endif /* TESTS_H */
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
--- /dev/null
+/* 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);