[LTP] [PATCh v2] clock_gettime04: print more info to help debugging

[Li Wang]

We catch some sporadically failures[1] like below, but we don't know which
test loop it comes from. So adding more prints to help locate issue.

  tst_test.c:1286: TINFO: Timeout per run is 0h 05m 00s
  vdso_helpers.c:76: TINFO: Couldn't find vdso_gettime64()
  clock_gettime04.c:157: TPASS: CLOCK_REALTIME: Difference between successive readings is reasonable
  clock_gettime04.c:150: TFAIL: CLOCK_REALTIME_COARSE: Difference between successive readings greater than 5 ms (1): 8
  clock_gettime04.c:157: TPASS: CLOCK_MONOTONIC: Difference between successive readings is reasonable
  clock_gettime04.c:150: TFAIL: CLOCK_MONOTONIC_COARSE: Difference between successive readings greater than 5 ms (0): 5
  clock_gettime04.c:157: TPASS: CLOCK_MONOTONIC_RAW: Difference between successive readings is reasonable
  clock_gettime04.c:157: TPASS: CLOCK_BOOTTIME: Difference between successive readings is reasonable

After patching, it will show more details about the iteration:

  tst_test.c:1288: TINFO: Timeout per run is 0h 05m 00s
  vdso_helpers.c:76: TINFO: Couldn't find vdso_gettime64()
  clock_gettime04.c:158: TPASS: CLOCK_REALTIME: Difference between successive readings is reasonable for following variants:
  clock_gettime04.c:162: TINFO:   - vDSO or syscall with libc spec
  clock_gettime04.c:162: TINFO:   - syscall with old kernel spec
  clock_gettime04.c:162: TINFO:   - vDSO with old kernel spec
  clock_gettime04.c:162: TINFO:   - gettimeofday
  clock_gettime04.c:158: TPASS: CLOCK_REALTIME_COARSE: Difference between successive readings is reasonable for following variants:
  clock_gettime04.c:162: TINFO:   - vDSO or syscall with libc spec
  clock_gettime04.c:162: TINFO:   - syscall with old kernel spec
  clock_gettime04.c:162: TINFO:   - vDSO with old kernel spec
  clock_gettime04.c:158: TPASS: CLOCK_MONOTONIC: Difference between successive readings is reasonable for following variants:
  clock_gettime04.c:162: TINFO:   - vDSO or syscall with libc spec
  clock_gettime04.c:162: TINFO:   - syscall with old kernel spec
  clock_gettime04.c:162: TINFO:   - vDSO with old kernel spec
  clock_gettime04.c:158: TPASS: CLOCK_MONOTONIC_COARSE: Difference between successive readings is reasonable for following variants:
  clock_gettime04.c:162: TINFO:   - vDSO or syscall with libc spec
  clock_gettime04.c:162: TINFO:   - syscall with old kernel spec
  clock_gettime04.c:162: TINFO:   - vDSO with old kernel spec
  clock_gettime04.c:158: TPASS: CLOCK_MONOTONIC_RAW: Difference between successive readings is reasonable for following variants:
  clock_gettime04.c:162: TINFO:   - vDSO or syscall with libc spec
  clock_gettime04.c:162: TINFO:   - syscall with old kernel spec
  clock_gettime04.c:162: TINFO:   - vDSO with old kernel spec
  clock_gettime04.c:158: TPASS: CLOCK_BOOTTIME: Difference between successive readings is reasonable for following variants:
  clock_gettime04.c:162: TINFO:   - vDSO or syscall with libc spec
  clock_gettime04.c:162: TINFO:   - syscall with old kernel spec
  clock_gettime04.c:162: TINFO:   - vDSO with old kernel spec

[1] it occurs on a x86_64 (not virtualized) with kernel 5.11.0.

Signed-off-by: Li Wang <liwang@redhat.com>
---
 .../kernel/syscalls/clock_gettime/clock_gettime04.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/testcases/kernel/syscalls/clock_gettime/clock_gettime04.c b/testcases/kernel/syscalls/clock_gettime/clock_gettime04.c
index 5f8264cc6..4a395f394 100644
--- a/testcases/kernel/syscalls/clock_gettime/clock_gettime04.c
+++ b/testcases/kernel/syscalls/clock_gettime/clock_gettime04.c
@@ -147,15 +147,20 @@ static void run(unsigned int i)
 			diff /= 1000000;
 
 			if (diff >= delta) {
-				tst_res(TFAIL, "%s: Difference between successive readings greater than %lld ms (%d): %lld",
-					tst_clock_name(clks[i]), delta, j, diff);
+				tst_res(TFAIL, "%s(%s): Difference between successive readings greater than %lld ms (%d): %lld",
+					tst_clock_name(clks[i]), tv->desc, delta, j, diff);
 				return;
 			}
 		}
 	} while (--count);
 
-	tst_res(TPASS, "%s: Difference between successive readings is reasonable",
-		tst_clock_name(clks[i]));
+	tst_res(TPASS, "%s: Difference between successive readings is reasonable for following variants:",
+			tst_clock_name(clks[i]));
+	for (j = 0; j < ARRAY_SIZE(variants); j++) {
+		if (variants[j].clock_gettime == my_gettimeofday && clks[i] != CLOCK_REALTIME)
+			continue;
+		tst_res(TINFO, "\t- %s", variants[j].desc);
+	}
 }
 
 static struct tst_test test = {
-- 
2.21.3