Messages in this thread | | | Date | Fri, 07 Mar 2003 10:20:19 -0800 | From | george anzinger <> | Subject | Re: POSIX timer syscalls |
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Eric Piel wrote: > george anzinger wrote: > >>By the way, I am seeing some reports from the clock_nanosleep test >>about sleeping too long or too short. The too long appears to be just >>not being able to preempt what ever else is running. The too short >>(on the x86) is, I believe, due to the fact that more that 1/HZ is >>clocked on the wall clock each jiffie. >> >>Try this: >> >>time sleep 60 >> >>On the x86 it reports less than 60, NOT good. >> > > I've run the test programs and they pass everything well (with my > patchs) excepted the nanosleeps which seems to be finnished a bit too > early. My system test is a 2.5.64 patched on a 4xItaniumII. > > My main question is to know if it's a problem even if the difference > between the wakeup time and the requested time is smaller than the > resolution of the clock, 976562ns ? I mean, at the resolution of the > clock we could consider we woke up right at the good time, couldn't we? > > In addition time sleep 60 always gave me time over 1 minute, I guess > it's a good point. > > Here is a part of the log of 'do_test': > > Testing behavor with clock seting... > Retarding the clock > Clock did not seem to move > was: 1046969027s 703359000ns > requested: 1046969023s 703359000ns > now: 1046969022s 467072000ns > diff is -1.236286998sec > Cool clock_nanosleeptest.c,379:clock_nanosleep(clock, TIMER_ABSTIME, > &ts, NULL)
Is it possible that a "clock_was_set()" call was missed? I.e in the set_timeofday code? > > Testing signal behavor... > handler1 entered: signal 31 > expected clock_nanosleeptest.c,227:clock_nanosleep(clock, 0, &ts, &rs): > Interrupted system call > Time remaining is 0s 989257306ns > clock_nanosleeptest.c,245:slept too short! > requested: 275s 207032000ns > now: 275s 207030632ns > diff is -0.000001368sec > > Testing undelivered signal behavor... > Cool clock_nanosleeptest.c,267:clock_nanosleep(clock, 0, &ts, &rs) > clock_nanosleeptest.c,283:slept too short! > requested: 275s 223633000ns > now: 275s 223632698ns > diff is -0.000000302sec > > > --Eric > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
-- George Anzinger george@mvista.com High-res-timers: http://sourceforge.net/projects/high-res-timers/ Preemption patch: http://www.kernel.org/pub/linux/kernel/people/rml
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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