Re: [PATCH 07/12] perf test: Add 'sqrtloop' test workload

[German Gomez <german.gomez@arm.com>]

On 09/11/2022 17:46, Namhyung Kim wrote:
> 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).
>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
>  tools/perf/tests/builtin-test.c       |  1 +
>  tools/perf/tests/tests.h              |  1 +
>  tools/perf/tests/workloads/Build      |  1 +
>  tools/perf/tests/workloads/sqrtloop.c | 44 +++++++++++++++++++++++++++
>  4 files changed, 47 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 0ed5ac452f6e..9acb7a93eeb9 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 86804dd6452b..18c40319e67c 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 631596bdb2b3..1ca95cb0fdb5 100644
> --- a/tools/perf/tests/workloads/Build
> +++ b/tools/perf/tests/workloads/Build
> @@ -3,5 +3,6 @@
>  perf-y += noploop.o
>  perf-y += thloop.o
>  perf-y += leafloop.o
> +perf-y += sqrtloop.o
>  
>  CFLAGS_leafloop.o         = -g -O0 -fno-inline -fno-omit-frame-pointer
> diff --git a/tools/perf/tests/workloads/sqrtloop.c b/tools/perf/tests/workloads/sqrtloop.c
> new file mode 100644
> index 000000000000..f7d1f8d4867b
> --- /dev/null
> +++ b/tools/perf/tests/workloads/sqrtloop.c
> @@ -0,0 +1,44 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#include <math.h>
> +#include <signal.h>
> +#include <stdlib.h>
> +#include <linux/compiler.h>
> +#include <sys/wait.h>
> +#include "../tests.h"
> +
> +static volatile int done;
> +
> +static void sighandler(int sig __maybe_unused)
> +{
> +	done = 1;
> +}
> +
> +static int __sqrtloop(int sec)
> +{
> +	signal(SIGALRM, sighandler);
> +	alarm(sec);
> +
> +	while (!done)
> +		sqrt(rand());
> +	return 0;
> +}

I get some implicit declaration errors on x86 build

(gcc (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0)

.  CC      tests/workloads/sqrtloop.o
.tests/workloads/sqrtloop.c: In function ‘__sqrtloop’:
.tests/workloads/sqrtloop.c:19:2: error: implicit declaration of function ‘alarm’ [-Werror=implicit-function-declaration]
.   19 |  alarm(sec);
.      |  ^~~~~
.tests/workloads/sqrtloop.c: In function ‘sqrtloop’:
.tests/workloads/sqrtloop.c:33:10: error: implicit declaration of function ‘fork’ [-Werror=implicit-function-declaration]
.   33 |  switch (fork()) {
.      |          ^~~~

> +
> +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);