commit feceaadd75c035ad2999b91266c4f3cd3c928d7d
Merge: 0c54ad0 763414b
Author: Stephen Rothwell <sfr@canb.auug.org.au>
Date:   Mon Mar 7 13:19:47 2011 +1100

    Merge remote-tracking branch 'block/for-next'
    
    Conflicts:
    	block/blk-flush.c

commit 1654e7411a1ad4999fe7890ef51d2a2bbb1fcf76
Author: Tejun Heo <tj@kernel.org>
Date:   Wed Mar 2 08:48:05 2011 -0500

    block: add @force_kblockd to __blk_run_queue()
    
    __blk_run_queue() automatically either calls q->request_fn() directly
    or schedules kblockd depending on whether the function is recursed.
    blk-flush implementation needs to be able to explicitly choose
    kblockd.  Add @force_kblockd.
    
    All the current users are converted to specify %false for the
    parameter and this patch doesn't introduce any behavior change.
    
    stable: This is prerequisite for fixing ide oops caused by the new
            blk-flush implementation.
    
    Signed-off-by: Tejun Heo <tj@kernel.org>
    Cc: Jan Beulich <JBeulich@novell.com>
    Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
    Cc: stable@kernel.org
    Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

commit 763414b132ab9d6f8e23657a87cc1dc823d1e34e
Merge: 6148a47 c186794
Author: Jens Axboe <jaxboe@fusionio.com>
Date:   Fri Feb 11 11:11:29 2011 +0100

    Merge branch 'for-2.6.39/core' into for-next
    
    Conflicts:
    	block/cfq-iosched.c
    
    Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

commit c186794dbb466b45cf40f942f2d09d6d5b4b0e42
Author: Mike Snitzer <snitzer@redhat.com>
Date:   Fri Feb 11 11:08:00 2011 +0100

    block: share request flush fields with  elevator_private
    
    Flush requests are never put on the IO scheduler.  Convert request
    structure's elevator_private* into an array and have the flush fields
    share a union with it.
    
    Reclaim the space lost in 'struct request' by moving 'completion_data'
    back in the union with 'rb_node'.
    
    Signed-off-by: Mike Snitzer <snitzer@redhat.com>
    Acked-by: Vivek Goyal <vgoyal@redhat.com>
    Acked-by: Tejun Heo <tj@kernel.org>
    Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

commit 02a8f01b5a9f396d0327977af4c232d0f94c45fd
Author: Justin TerAvest <teravest@google.com>
Date:   Wed Feb 9 14:20:03 2011 +0100

    cfq-iosched: Don't wait if queue already has requests.
    
    Commit 7667aa0630407bc07dc38dcc79d29cc0a65553c1 added logic to wait for
    the last queue of the group to become busy (have at least one request),
    so that the group does not lose out for not being continuously
    backlogged. The commit did not check for the condition that the last
    queue already has some requests. As a result, if the queue already has
    requests, wait_busy is set. Later on, cfq_select_queue() checks the
    flag, and decides that since the queue has a request now and wait_busy
    is set, the queue is expired.  This results in early expiration of the
    queue.
    
    This patch fixes the problem by adding a check to see if queue already
    has requests. If it does, wait_busy is not set. As a result, time slices
    do not expire early.
    
    The queues with more than one request are usually buffered writers.
    Testing shows improvement in isolation between buffered writers.
    
    Cc: stable@kernel.org
    Signed-off-by: Justin TerAvest <teravest@google.com>
    Reviewed-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
    Acked-by: Vivek Goyal <vgoyal@redhat.com>
    Signed-off-by: Jens Axboe <jaxboe@fusionio.com>