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    SubjectRe: [Lse-tech] Re: [PATCH][RFC] Proposal For A More Scalable Scheduler ...
    * Davide Libenzi <davidel@xmailserver.org> [20011031 18;53]:"
    > On Wed, 31 Oct 2001, Mike Kravetz wrote:
    >
    > > I'm going to try and merge your 'cache warmth' replacement for
    > > PROC_CHANGE_PENALTY into the LSE MQ scheduler, as well as enable
    > > the code to prevent task stealing during IPI delivery. This
    > > should still be significantly different than your design because
    > > MQ will still attempt to make global decisions. Results should
    > > be interesting.
    >
    > I'm currently evaluating different weights for that.
    > Right now I'm using :
    >
    > if (p->cpu_jtime > jiffies)
    > weight += p->cpu_jtime - jiffies;
    >
    > that might be too much.
    > Solutions :
    >
    > 1)
    > if (p->cpu_jtime > jiffies)
    > weight += (p->cpu_jtime - jiffies) >> 1;
    >
    > 2)
    > int wtable[];
    >
    > if (p->cpu_jtime > jiffies)
    > weight += wtable[p->cpu_jtime - jiffies];
    >
    > Speed will like 1).
    > Other optimization is jiffies that is volatile and forces gcc to always
    > reload it.
    >
    > static inline int goodness(struct task_struct * p, struct mm_struct
    > *this_mm, unsigned long jiff)
    >
    > might be better, with jiffies taken out of the goodness loop.
    > Mike I suggest you to use the LatSched patch to 1) know how really is
    > performing the scheduler 2) understand if certain test gives certain
    > results due wierd distributions.
    >

    One more. Throughout our MQ evaluation, it was also true that
    the overall performance particularly for large thread counts was
    very sensitive to the goodness function, that why a na_goodness_local
    was introduced.

    -- Hubertus
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