Re: [PATCH] selftests: intel_pstate: ftime() is deprecated

[Shuah Khan <skhan@linuxfoundation.org>]

Hi Tommi,

On 10/16/20 7:22 AM, Tommi Rantala wrote:
> Use clock_gettime() instead of deprecated ftime().
> 
>    aperf.c: In function ‘main’:
>    aperf.c:58:2: warning: ‘ftime’ is deprecated [-Wdeprecated-declarations]
>       58 |  ftime(&before);
>          |  ^~~~~
>    In file included from aperf.c:9:
>    /usr/include/sys/timeb.h:39:12: note: declared here
>       39 | extern int ftime (struct timeb *__timebuf)
>          |            ^~~~~
> 

Thanks for the fix. One comment below

> Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com>
> ---
>   tools/testing/selftests/intel_pstate/aperf.c | 17 ++++++++++++-----
>   1 file changed, 12 insertions(+), 5 deletions(-)
> 
> diff --git a/tools/testing/selftests/intel_pstate/aperf.c b/tools/testing/selftests/intel_pstate/aperf.c
> index f6cd03a87493..eea9dbab459b 100644
> --- a/tools/testing/selftests/intel_pstate/aperf.c
> +++ b/tools/testing/selftests/intel_pstate/aperf.c
> @@ -10,6 +10,7 @@
>   #include <sched.h>
>   #include <errno.h>
>   #include <string.h>
> +#include <time.h>
>   #include "../kselftest.h"
>   
>   void usage(char *name) {
> @@ -22,7 +23,7 @@ int main(int argc, char **argv) {
>   	long long tsc, old_tsc, new_tsc;
>   	long long aperf, old_aperf, new_aperf;
>   	long long mperf, old_mperf, new_mperf;
> -	struct timeb before, after;
> +	struct timespec before, after;
>   	long long int start, finish, total;
>   	cpu_set_t cpuset;
>   
> @@ -55,7 +56,10 @@ int main(int argc, char **argv) {
>   		return 1;
>   	}
>   
> -	ftime(&before);
> +	if (clock_gettime(CLOCK_MONOTONIC, &before) < 0) {
> +		perror("clock_gettime");
> +		return 1;
> +	}
>   	pread(fd, &old_tsc,  sizeof(old_tsc), 0x10);
>   	pread(fd, &old_aperf,  sizeof(old_mperf), 0xe7);
>   	pread(fd, &old_mperf,  sizeof(old_aperf), 0xe8);
> @@ -64,7 +68,10 @@ int main(int argc, char **argv) {
>   		sqrt(i);
>   	}
>   
> -	ftime(&after);
> +	if (clock_gettime(CLOCK_MONOTONIC, &after) < 0) {
> +		perror("clock_gettime");
> +		return 1;
> +	}
>   	pread(fd, &new_tsc,  sizeof(new_tsc), 0x10);
>   	pread(fd, &new_aperf,  sizeof(new_mperf), 0xe7);
>   	pread(fd, &new_mperf,  sizeof(new_aperf), 0xe8);
> @@ -73,8 +80,8 @@ int main(int argc, char **argv) {
>   	aperf = new_aperf-old_aperf;
>   	mperf = new_mperf-old_mperf;
>   
> -	start = before.time*1000 + before.millitm;
> -	finish = after.time*1000 + after.millitm;
> +	start = before.tv_sec*1000 + before.tv_nsec/1000000L;
> +	finish = after.tv_sec*1000 + after.tv_nsec/1000000L;

Why not use timespec dNSEC_PER_MSEC define from  include/vdso/time64.h?

thanks,
-- Shuah