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

[Shuah Khan]

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.rant...@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