lkml.org 
[lkml]   [2011]   [Dec]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 3/3] slub: fill per cpu partial only when free objects larger than one quarter
    Date
    From: Alex Shi <alexs@intel.com>

    Set selection criteria when fill per cpu partial in slow allocation path,
    and check the PCP left space before filling, even maybe the data from another
    CPU.
    The patch can bring another 1.5% performance increase on netperf loopback
    testing for our 4 or 2 sockets machines, include sandbridge, core2

    Signed-off-by: Alex Shi <alex.shi@intel.com>
    ---
    mm/slub.c | 43 +++++++++++++++++++++++++++++++------------
    1 files changed, 31 insertions(+), 12 deletions(-)

    diff --git a/mm/slub.c b/mm/slub.c
    index 65d901f..72df387 100644
    --- a/mm/slub.c
    +++ b/mm/slub.c
    @@ -1542,25 +1542,44 @@ static void *get_partial_node(struct kmem_cache *s,

    spin_lock(&n->list_lock);
    list_for_each_entry_safe(page, page2, &n->partial, lru) {
    - void *t = acquire_slab(s, n, page, object == NULL);
    int available;
    + void *t;
    + struct page *oldpage;
    + int pobjects;

    - if (!t)
    - break;

    if (!object) {
    - c->page = page;
    - c->node = page_to_nid(page);
    - stat(s, ALLOC_FROM_PARTIAL);
    - object = t;
    - available = page->objects - page->inuse;
    + t = acquire_slab(s, n, page, object == NULL);
    + if (!t)
    + break;
    + else {
    + c->page = page;
    + c->node = page_to_nid(page);
    + stat(s, ALLOC_FROM_PARTIAL);
    + object = t;
    + }
    } else {
    - page->freelist = t;
    - available = put_cpu_partial(s, page, 0);
    + oldpage = this_cpu_read(s->cpu_slab->partial);
    + pobjects = oldpage ? oldpage->pobjects : 0;
    +
    + if (pobjects > s->cpu_partial / 2)
    + break;
    +
    + available = page->objects - page->inuse;
    + if (available >= s->cpu_partial / 4) {
    + t = acquire_slab(s, n, page, object == NULL);
    + if (!t)
    + break;
    + else {
    + page->freelist = t;
    + if (put_cpu_partial(s, page, 0) >
    + s->cpu_partial / 2)
    + break;
    + }
    + }
    }
    - if (kmem_cache_debug(s) || available > s->cpu_partial / 2)
    + if (kmem_cache_debug(s))
    break;
    -
    }
    spin_unlock(&n->list_lock);
    return object;
    --
    1.7.0.1


    \
     
     \ /
      Last update: 2011-12-02 09:27    [W:0.030 / U:58.444 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site