lkml.org 
[lkml]   [2012]   [Jan]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH] x86,sched: Fix sched_smt_power_savings totally broken
    From
    Date
    On Mon, 2012-01-09 at 19:14 -0500, Youquan Song wrote:
    > Fine, I will base your suggestion to develop another patch soon.
    >

    >
    > @@ -3923,6 +3923,10 @@ static inline void update_sg_lb_stats(struct
    > sched_domain *sd,
    > SCHED_POWER_SCALE);
    > if (!sgs->group_capacity)
    > sgs->group_capacity = fix_small_capacity(sd, group);
    > +
    > + if (sched_smt_power_savings)
    > + sgs->group_capacity *= 2;

    Note, this has the hard-coded assumption you only have 2 threads per
    core, which while true for intel, isn't true in general. I think you
    meant to write *= group->group_weight or somesuch.

    Also, you forgot to limit this to the SD_SHARE_CPUPOWER domain, you're
    now doubling the capacity for all domains.

    Furthermore, have a look at the SD_PREFER_SIBLING logic and make sure
    you're not fighting that.


    \
     
     \ /
      Last update: 2012-01-09 12:09    [W:0.019 / U:90.620 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site