Date: Sun, 12 Feb 2006 15:48:55 -0500 From: Kris Kennaway <kris@obsecurity.org> To: Poul-Henning Kamp <phk@phk.freebsd.dk> Cc: Yuriy Tsibizov <Yuriy.Tsibizov@gfk.ru>, freebsd-current@freebsd.org Subject: Re: calcru: runtime went backwards Message-ID: <20060212204855.GA94458@xor.obsecurity.org> In-Reply-To: <29218.1139772457@critter.freebsd.dk> References: <20060212220216.F1605@free.home.local> <29218.1139772457@critter.freebsd.dk>
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[-- Attachment #1 --] On Sun, Feb 12, 2006 at 07:27:37PM +0000, Poul-Henning Kamp wrote: > In message <20060212220216.F1605@free.home.local>, Yuriy Tsibizov writes: > >On Sun, 12 Feb 2006, Poul-Henning Kamp wrote: > >> In message <20060212114050.I1160@free.home.local>, Yuriy Tsibizov writes: > >>> while playing 8 PCM streams in parallel (it uses almost all CPU power I > >>> have). > >>> > >>> -CURRENT with last changes to src/sys from imp at 2006-02-11 03:58:07 UTC > >> > >> Can you try to update to a more recent current ? I think you have > >> not gotten my latest commit to the cpu time accounting at that > >> point... > >With -CURRENT up to 2006-02-12 06:57:41 UTC (last commit by scottl) > >I still can see some calcru messages: > > Right, but these have much smaller deltas than the other ones you saw. > > >calcru: runtime went backwards from 3508844 usec to 3508842 usec for pid 28 (pagezero) > > My theory currently is that these are side effects of the cputick > calibration code: If the cputick rate gets measured to be a bit higher, > the next calculation will result in slightly lower numbers for the > cpu utilization in microseconds and the warning will fire. > > This will be particularly easy to trigger on machines with power > management on (laptops mostly). > > My current inclination is to simply not issue this warning if the > cpu_tick is marked as "variable". My machine should not be varying CPU-speed either. Kris [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (FreeBSD) iD8DBQFD7583Wry0BWjoQKURApM8AJ96wY0SUvWkw/ooXFzEQTYxzWoapACgq2tW 4inK4F1tj9m3stCv9Hxk3jY= =82Ct -----END PGP SIGNATURE-----
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