Messages in this thread | | | Subject | Re: [patch] voluntary-preempt-2.6.8.1-P0 | From | Lee Revell <> | Date | Sun, 15 Aug 2004 19:51:23 -0400 |
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On Sun, 2004-08-15 at 07:56, Ingo Molnar wrote: > i've uploaded the -P0 patch: > > http://redhat.com/~mingo/voluntary-preempt/voluntary-preempt-2.6.8.1-P0 > > those who had APIC (and USB, under SMP) problems under previous > versions, are the problems still present in -P0? >
The mlockall issue is still not resolved; however, I did manage to get a trace, which was probably not possible before because some higher latency but lower frequency event was overwriting /proc/latency_trace. So, maybe mlockall does cause xruns by having many shorter, but long enough to be problematic, non-preemptible sections.
http://krustophenia.net/testresults.php?dataset=2.6.8.1-P0
Also it seems that extract_entropy still causes high latencies, even though a call to preempt_schedule was added. I looked at the code in random.c a bit and this strikes me as an area where the algorithm could be improved, rather than adding a scheduling point. Do we really need *that* much entropy, right then? And if so, isn't there a zero-copy solution?
Lee
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