Messages in this thread | | | From | Gene Heskett <> | Subject | Re: Real-Time Preemption, -RT-2.6.10-rc2-mm3-V0.7.31-13 | Date | Mon, 29 Nov 2004 18:16:43 -0500 |
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On Monday 29 November 2004 10:23, Ingo Molnar wrote: >* Ingo Molnar <mingo@elte.hu> wrote: >> but please try to the -31-10 kernel that i've just uploaded, it >> has a number of tracer enhancements: > >make that -31-13 (or later). Earlier kernels had a bug in where the >process name tracking only worked for the first latency trace saved, >subsequent traces showed 'unknown' for the process name. In -13 i've >also added a printk that shows the latest user latency in a one-line >printk - just like the built-in latency tracing modes do: > > (gettimeofday/3671/CPU#0): new 3068 us user-latency. > (gettimeofday/3784/CPU#0): new 1008627 us user-latency. > >(this should also make it easier for helper scripts to save the > traces, whenever they happen.) > > Ingo
I just built this to see how much blood it would draw, which isn't much. I don't have jack here, so I don't have your standard torture test. Instead, I run tvtime, which runs at a -19 priority.
I let it run about 30 seconds (untimed), noted that the frame error slippage wasn't improved, and got this output histogram when I quit it.
Its (tvtime) is running here of course. -------------------- Nov 29 18:05:45 coyote kernel: Read missed before next interrupt Nov 29 18:05:45 coyote kernel: wow! That was a 22 millisec bump Nov 29 18:05:45 coyote kernel: `IRQ 8'[846] is being piggy. need_resched=0, cpu=0 Nov 29 18:05:45 coyote kernel: Read missed before next interrupt Nov 29 18:05:45 coyote kernel: wow! That was a 22 millisec bump Nov 29 18:05:45 coyote kernel: `IRQ 8'[846] is being piggy. need_resched=0, cpu=0 Nov 29 18:05:45 coyote kernel: Read missed before next interrupt Nov 29 18:05:45 coyote kernel: wow! That was a 21 millisec bump Nov 29 18:05:45 coyote kernel: `IRQ 8'[846] is being piggy. need_resched=0, cpu=0 Nov 29 18:05:45 coyote kernel: Read missed before next interrupt Nov 29 18:05:45 coyote kernel: wow! That was a 21 millisec bump Nov 29 18:05:45 coyote kernel: `IRQ 8'[846] is being piggy. need_resched=0, cpu=0 Nov 29 18:05:45 coyote kernel: Read missed before next interrupt Nov 29 18:05:45 coyote kernel:
And was stopped here.
Nov 29 18:05:45 coyote kernel: rtc latency histogram of {tvtime/3398, 10609 samples}: Nov 29 18:05:45 coyote kernel: 4 11 Nov 29 18:05:45 coyote kernel: 5 1716 Nov 29 18:05:45 coyote kernel: 6 4827 Nov 29 18:05:45 coyote kernel: 7 1495 Nov 29 18:05:45 coyote kernel: 8 382 Nov 29 18:05:45 coyote kernel: 9 193 Nov 29 18:05:45 coyote kernel: 10 206 Nov 29 18:05:45 coyote kernel: 11 188 Nov 29 18:05:45 coyote kernel: 12 148 Nov 29 18:05:45 coyote kernel: 13 202 Nov 29 18:05:45 coyote kernel: 14 195 Nov 29 18:05:45 coyote kernel: 15 95 Nov 29 18:05:45 coyote kernel: 16 70 Nov 29 18:05:45 coyote kernel: 17 23 Nov 29 18:05:45 coyote kernel: 18 18 Nov 29 18:05:45 coyote kernel: 19 8 Nov 29 18:05:45 coyote kernel: 20 9 Nov 29 18:05:45 coyote kernel: 21 1 Nov 29 18:05:45 coyote kernel: 22 1 Nov 29 18:05:45 coyote kernel: 26 1 -------------------- And I note that the 1-26 column of numbers does not seem to add up to whats being logged above there, which are all 21 and 22 ms bumps (whatever a bump is)
Is this a helpfull report, or just noise? Subjectively, tvtime is running with far fewer visible frame glitches than before I started playing with these patches. A marked improvement IMO.
-- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) 99.29% setiathome rank, not too shabby for a WV hillbilly Yahoo.com attorneys please note, additions to this message by Gene Heskett are: Copyright 2004 by Maurice Eugene Heskett, all rights reserved. - 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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