aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/tools/testing/selftests/timers/adjtick.c (follow)
AgeCommit message (Collapse)AuthorFilesLines
2015-10-12timers, kselftest: Add 'adjtick' test to validate adjtimex() tick adjustmentsJohn Stultz1-0/+221
Recently a kernel side NTP bug was fixed via the following commit: 2619d7e9c92d ("time: Fix timekeeping_freqadjust()'s incorrect use of abs() instead of abs64()") When the bug was reported it was difficult to detect, except by tweaking the adjtimex tick value, and noticing how quickly the adjustment took: https://lkml.org/lkml/2015/9/1/488 Thus this patch introduces a new test which manipulates the adjtimex tick value and validates that the results are what we expect. Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Miroslav Lichvar <mlichvar@redhat.com> Cc: Nuno Gonçalves <nunojpg@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Shuah Khan <shuahkh@osg.samsung.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1444094217-20258-1-git-send-email-john.stultz@linaro.org [ Tidied up the code and the changelog a bit. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>