lkml.org 
[lkml]   [2010]   [Jan]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] sched: cpuacct: Use bigger percpu counter batch values for stats counters

    Hi Martin,

    > For s390 the jiffies_to_cputime is a compile time constant. No need to
    > initialize it at runtime, no?

    Indeed it is, I didn't look closely enough. Same with ia64 so no work to
    do on either arch :)

    > The patch itself trades some accuracy (larger cpu accounting value that
    > are stored per-cpu) against runtime overhead (spinlock to transfer the
    > value to the global variable in __percpu_counter_add). Did you
    > calculate how big the loss in accuracy is?

    The idea is we are already batching percpu_counter_batch jiffies, so
    with CONFIG_VIRT_CPU_ACCOUNTING we batch the equivalent amount in
    cputime.

    Anton


    \
     
     \ /
      Last update: 2010-01-18 10:59    [W:0.027 / U:29.600 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site