Commit a6327162 authored by Shaohua Li's avatar Shaohua Li Committed by Jens Axboe
Browse files

block: change force plug flush call order



Do blk_flush_plug_list() first and then add new request aDo blk_flush_plug_list() first and then add new request aDo blk_flush_plug_list() first and then add new request at the tail. New
request can't be merged to existing requests, but later new requests might
be merged with this new one. If blk_flush_plug_list() is done later, the
merge doesn't happen.
Believe it or not, this fixes a 10% regression running sysbench workload.
Signed-off-by: default avatarShaohua Li <shli@kernel.org>
Signed-off-by: default avatarShaohua Li <shaohua.li@intel.com>
Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
parent e8037d49
......@@ -1302,11 +1302,11 @@ get_rq:
if (__rq->q != q)
plug->should_sort = 1;
}
list_add_tail(&req->queuelist, &plug->list);
plug->count++;
drive_stat_acct(req, 1);
if (plug->count >= BLK_MAX_REQUEST_COUNT)
blk_flush_plug_list(plug, false);
plug->count++;
list_add_tail(&req->queuelist, &plug->list);
drive_stat_acct(req, 1);
} else {
spin_lock_irq(q->queue_lock);
add_acct_request(q, req, where);
......
Supports Markdown
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment