On Wed, Sep 16, 2026 at 6:52 PM Eva Kurchatova <[email protected]> wrote: > > Commit b00385b8d081 ("selftests/posix_timers: Use CLOCK_THREAD_CPUTIME_ID > for ITIMER_PROF measurements") gave ITIMER_PROF the clock it counts, as > measuring a CPU timer against the wall says nothing on a machine where > the task does not have a CPU to itself. The other CPU timers are still > measured against CLOCK_REALTIME and fail the same way. With four busy > loops on the two CPUs of a test machine: > > not ok 2 ITIMER_VIRTUAL > not ok 5 timer_create() per CLOCK_THREAD_CPUTIME_ID > not ok 6 timer_create() per CLOCK_PROCESS_CPUTIME_ID > > ITIMER_VIRTUAL counts the time the task spends in userspace, so take > CLOCK_THREAD_CPUTIME_ID for it as well; the loop it runs stays in > userspace, so what that clock adds for system time is far inside the > half a second the check allows. check_timer_create() arms its timer on > the clock it is given, so measure on that one. > > The test then passes whole on that machine, 19 of 19, busy or idle. > > Signed-off-by: Eva Kurchatova <[email protected]>
Looks reasonable to me. Acked-by: John Stultz <[email protected]> thanks -john
