lkml.org 
[lkml]   [2019]   [May]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.1 007/405] sbitmap: fix improper use of smp_mb__before_atomic()
    Date
    From: Andrea Parri <andrea.parri@amarulasolutions.com>

    commit a0934fd2b1208458e55fc4b48f55889809fce666 upstream.

    This barrier only applies to the read-modify-write operations; in
    particular, it does not apply to the atomic_set() primitive.

    Replace the barrier with an smp_mb().

    Fixes: 6c0ca7ae292ad ("sbitmap: fix wakeup hang after sbq resize")
    Cc: stable@vger.kernel.org
    Reported-by: "Paul E. McKenney" <paulmck@linux.ibm.com>
    Reported-by: Peter Zijlstra <peterz@infradead.org>
    Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com>
    Reviewed-by: Ming Lei <ming.lei@redhat.com>
    Cc: Jens Axboe <axboe@kernel.dk>
    Cc: Omar Sandoval <osandov@fb.com>
    Cc: Ming Lei <ming.lei@redhat.com>
    Cc: linux-block@vger.kernel.org
    Cc: "Paul E. McKenney" <paulmck@linux.ibm.com>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Signed-off-by: Jens Axboe <axboe@kernel.dk>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    lib/sbitmap.c | 2 +-
    1 file changed, 1 insertion(+), 1 deletion(-)

    --- a/lib/sbitmap.c
    +++ b/lib/sbitmap.c
    @@ -435,7 +435,7 @@ static void sbitmap_queue_update_wake_ba
    * to ensure that the batch size is updated before the wait
    * counts.
    */
    - smp_mb__before_atomic();
    + smp_mb();
    for (i = 0; i < SBQ_WAIT_QUEUES; i++)
    atomic_set(&sbq->ws[i].wait_cnt, 1);
    }

    \
     
     \ /
      Last update: 2019-05-30 05:10    [W:3.476 / U:0.168 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site