Messages in this thread | | | From | Con Kolivas <> | Subject | Re: Scheduler fairness problem on 2.6 series (Attn: Nick Piggin and others) | Date | Wed, 11 Aug 2004 13:31:16 +1000 |
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Peter Williams writes:
> Peter Williams wrote: >> Peter Williams wrote: >> >>> William Lee Irwin III wrote: >>> >>>> On Tue, Aug 10, 2004 at 07:21:43PM -0700, spaminos-ker@yahoo.com wrote: >>>> >>>>> I am not very familiar with all the parameters, so I just kept the >>>>> defaults >>>>> Anything else I could try? >>>>> Nicolas >>>> >>>> >>>> >>>> >>>> No. It appeared that the SPA bits had sufficient fairness in them to >>>> pass this test but apparently not quite enough. >>>> >>> >>> The interactive bonus may interfere with fairness (the throughput >>> bonus should actually help it for tasks with equal nice) so you could >>> try setting max_ia_bonus to zero (and possibly increasing >>> max_tpt_bonus). With "eb" mode this should still give good interactive >>> response but expect interactive response to suffer a little in "pb" >>> mode however renicing the X server to a negative value should help. >> >> >> I should also have mentioned that fiddling with the promotion interval >> may help. > > Having reread your original e-mail I think that this problem is probably > being caused by the interactive bonus mechanism classifying the httpd > server threads as "interactive" threads and giving them a bonus. But > for some reason the daemon is not identified as "interactive" meaning > that it gets given a lower priority. In this situation if there's a > large number of httpd threads (even with promotion) it could take quite > a while for the daemon to get a look in. Without promotion total > starvation is even a possibility. > > Peter > PS For both "eb" and "pb" modes, max_io_bonus should be set to zero on > servers (where interactive responsiveness isn't an issue). > PPS For "sc" mode, try setting "interactive" to zero and "compute" to 1.
No, compute should not be set to 1 for a server. It is reserved only for computational nodes, not regular servers. "Compute" will increase latency which is undersirable.
Cheers, Con
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