lkml.org 
[lkml]   [2013]   [Oct]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[tip:sched/core] sched/numa: Take false sharing into account when adapting scan rate
    Commit-ID:  3e6a9418cf05638b103e34f5d13be0321872e623
    Gitweb: http://git.kernel.org/tip/3e6a9418cf05638b103e34f5d13be0321872e623
    Author: Mel Gorman <mgorman@suse.de>
    AuthorDate: Mon, 7 Oct 2013 11:29:35 +0100
    Committer: Ingo Molnar <mingo@kernel.org>
    CommitDate: Wed, 9 Oct 2013 14:48:14 +0200

    sched/numa: Take false sharing into account when adapting scan rate

    Scan rate is altered based on whether shared/private faults dominated.
    task_numa_group() may detect false sharing but that information is not
    taken into account when adapting the scan rate. Take it into account.

    Signed-off-by: Mel Gorman <mgorman@suse.de>
    Reviewed-by: Rik van Riel <riel@redhat.com>
    Cc: Andrea Arcangeli <aarcange@redhat.com>
    Cc: Johannes Weiner <hannes@cmpxchg.org>
    Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
    Signed-off-by: Peter Zijlstra <peterz@infradead.org>
    Link: http://lkml.kernel.org/r/1381141781-10992-58-git-send-email-mgorman@suse.de
    Signed-off-by: Ingo Molnar <mingo@kernel.org>
    ---
    kernel/sched/fair.c | 8 ++++++--
    1 file changed, 6 insertions(+), 2 deletions(-)

    diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
    index 222c2d0..d26a16e 100644
    --- a/kernel/sched/fair.c
    +++ b/kernel/sched/fair.c
    @@ -1381,7 +1381,8 @@ static void double_lock(spinlock_t *l1, spinlock_t *l2)
    spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
    }

    -static void task_numa_group(struct task_struct *p, int cpupid, int flags)
    +static void task_numa_group(struct task_struct *p, int cpupid, int flags,
    + int *priv)
    {
    struct numa_group *grp, *my_grp;
    struct task_struct *tsk;
    @@ -1447,6 +1448,9 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags)
    if (flags & TNF_SHARED)
    join = true;

    + /* Update priv based on whether false sharing was detected */
    + *priv = !join;
    +
    if (join && !get_numa_group(grp))
    join = false;

    @@ -1545,7 +1549,7 @@ void task_numa_fault(int last_cpupid, int node, int pages, int flags)
    } else {
    priv = cpupid_match_pid(p, last_cpupid);
    if (!priv && !(flags & TNF_NO_GROUP))
    - task_numa_group(p, last_cpupid, flags);
    + task_numa_group(p, last_cpupid, flags, &priv);
    }

    /*

    \
     
     \ /
      Last update: 2013-10-09 20:21    [W:4.075 / U:0.076 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site