tree 416c0654b652509ffc70e3b7ab0b238c3e0ead3c
parent b4d33ed0ef791f819f66071f68e5cd897bee27c5
author Li Wang <liwang@redhat.com> 1648530231 +0800
committer Cixi Geng <cixi.geng1@unisoc.com> 1665717533 +0800

BACKPORT: clock_gettime04: set threshold based on the clock resolution

This is to get rid of the intermittent failures in clock_gettime04,
which are likely caused by different clock tick rates on platforms.
Here give two thresholds (in milliseconds) for comparison, one for
COARSE clock and one for the rest.

Error log:
  clock_gettime04.c:163: TFAIL: CLOCK_REALTIME_COARSE(syscall with old kernel spec):
        Difference between successive readings greater than 5 ms (1): 10
  clock_gettime04.c:163: TFAIL: CLOCK_MONOTONIC_COARSE(vDSO with old kernel spec):
	Difference between successive readings greater than 5 ms (2): 10

From Waiman Long:
  That failure happens for CLOCK_REALTIME_COARSE which is a faster but less
  precise version of CLOCK_REALTIME. The time resolution is actually a clock
  tick. Since arm64 has a HZ rate of 100. That means each tick is 10ms. So a
  CLOCK_REALTIME_COARSE threshold of 5ms is probably not enough. I would say
  in the case of CLOCK_REALTIME_COARSE, we have to increase the threshold based
  on the clock tick rate of the system. This is more a test failure than is
  an inherent problem in the kernel.

Fixes #898

Reported-by: Eirik Fuller <efuller@redhat.com>
Signed-off-by: Li Wang <liwang@redhat.com>
Cc: Waiman Long <llong@redhat.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Cyril Hrubis <chrubis@suse.cz>
Acked-by: Waiman Long <longman@redhat.com>
Bug: 253210281
Change-Id: I2a5145c791f3f8b99ce7f3b4015845e01aad17a7
Signed-off-by: Cixi Geng <cixi.geng1@unisoc.com>