Messages in this thread | | | Date | Mon, 11 Aug 2008 09:27:04 -0400 | From | Gregory Haskins <> | Subject | Re: [revert] mysql+oltp regression |
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Gregory Haskins wrote: > Ingo Molnar wrote: >> * Gregory Haskins <ghaskins@novell.com> wrote: >> >> >>>>> Speaking of this: Another patch I submitted to you Ingo (had to do >>>>> with updating the load_weight inside task_setprio) seems to also >>>>> have this phenomenon: e.g. its technically correct but further >>>>> testing has revealed negative repercussions elsewhere. So please >>>>> ignore that patch (or revert if you already pulled in, but I don't >>>>> think you have). Ill try to look into this issue as well. >>>>> >>>> ok, under which thread/subject is that? Not queued in tip/sched/* >>>> yet, correct? >>>> >>> Here is the original thread: >>> >>> http://lkml.org/lkml/2008/7/3/416 >>> >>> I do not believe you have queued it anywhere (public anyway) yet. >>> >>> Note I have already invalidated 1/2, and now I am retracting 2/2 as >>> well. (1/2 is actually a bogus patch, 2/2 is "technically correct" >>> but causes ripples in the load balancer that need to be sorted out >>> first. >>> >> >> ok, thanks. I'm curious, what are those ripple effects? Stability or >> performance? >> > > Performance. I found it while working on my pi series (which fyi I > should have a v2 refresh for soon, probably today...i am hoping to get > some review feedback from you on that as well, time permitting of > course ;). > > Basically the behavior I was observing was that kernel builds via > distcc would cluster all the cc1 jobs on a single core. At first I > thought my pi-series was screwed up, but then I realized I had applied > the patch referenced above earlier in my development tree, and > removing it allowed pi to work fine. > > I found the problem with in once boot cycle with ftrace (thanks Steve!).
Hmm..Im not sure what went wrong between brain and hand above, but of course I meant to say ".. within one boot cycle ..", not "with in once". Heh.
> Basically newidle balancing was always returning "no imbalance" even > though I had 32 cc1 threads on 1 core, and 3 idle cores. Clearly not > correct! So I think that by adjusting the load up, we throw off the > hysteresis built into the load averages and cause the system to > incorrectly think it's balanced. TBD. > > -Greg > > >> Ingo >> > >
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