lkml.org 
[lkml]   [2010]   [Mar]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    SubjectRe: [patch 10/12] sched: remove SYNC_WAKEUPS feature
    From
    Date

    sched: remove SYNC_WAKEUPS feature

    Sync wakeups are critical functionality with a long history. Remove it, we don't
    need the branch or icache footprint.

    Signed-off-by: Mike Galbraith <efault@gmx.de>
    Cc: Ingo Molnar <mingo@elte.hu>
    Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
    LKML-Reference: <new-submission>

    ---
    kernel/sched.c | 3 ---
    kernel/sched_features.h | 8 --------
    2 files changed, 11 deletions(-)

    Index: linux-2.6/kernel/sched.c
    ===================================================================
    --- linux-2.6.orig/kernel/sched.c
    +++ linux-2.6/kernel/sched.c
    @@ -2369,9 +2369,6 @@ static int try_to_wake_up(struct task_st
    unsigned long flags;
    struct rq *rq, *orig_rq;

    - if (!sched_feat(SYNC_WAKEUPS))
    - wake_flags &= ~WF_SYNC;
    -
    this_cpu = get_cpu();

    smp_wmb();
    Index: linux-2.6/kernel/sched_features.h
    ===================================================================
    --- linux-2.6.orig/kernel/sched_features.h
    +++ linux-2.6/kernel/sched_features.h
    @@ -17,14 +17,6 @@ SCHED_FEAT(START_DEBIT, 1)
    SCHED_FEAT(WAKEUP_PREEMPT, 1)

    /*
    - * Use the SYNC wakeup hint, pipes and the likes use this to indicate
    - * the remote end is likely to consume the data we just wrote, and
    - * therefore has cache benefit from being placed on the same cpu, see
    - * also AFFINE_WAKEUPS.
    - */
    -SCHED_FEAT(SYNC_WAKEUPS, 1)
    -
    -/*
    * Based on load and program behaviour, see if it makes sense to place
    * a newly woken task on the same cpu as the task that woke it --
    * improve cache locality. Typically used with SYNC wakeups as



    \
     
     \ /
      Last update: 2010-03-11 11:05    [W:0.021 / U:328.804 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site