lkml.org 
[lkml]   [2012]   [Jun]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 2/3] slub: reduce failure of this_cpu_cmpxchg in put_cpu_partial() after unfreezing
    Date
    In current implementation, after unfreezing, we doesn't touch oldpage,
    so it remain 'NOT NULL'. When we call this_cpu_cmpxchg()
    with this old oldpage, this_cpu_cmpxchg() is mostly be failed.

    We can change value of oldpage to NULL after unfreezing,
    because unfreeze_partial() ensure that all the cpu partial slabs is removed
    from cpu partial list. In this time, we could expect that
    this_cpu_cmpxchg is mostly succeed.

    Signed-off-by: Joonsoo Kim <js1304@gmail.com>

    diff --git a/mm/slub.c b/mm/slub.c
    index 92f1c0e..531d8ed 100644
    --- a/mm/slub.c
    +++ b/mm/slub.c
    @@ -1968,6 +1968,7 @@ int put_cpu_partial(struct kmem_cache *s, struct page *page, int drain)
    local_irq_save(flags);
    unfreeze_partials(s);
    local_irq_restore(flags);
    + oldpage = NULL;
    pobjects = 0;
    pages = 0;
    stat(s, CPU_PARTIAL_DRAIN);
    --
    1.7.9.5


    \
     
     \ /
      Last update: 2012-06-22 21:01    [W:0.021 / U:30.544 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site