From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39779) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XEVWr-0003x0-5F for qemu-devel@nongnu.org; Mon, 04 Aug 2014 23:35:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XEVWi-0001kY-No for qemu-devel@nongnu.org; Mon, 04 Aug 2014 23:35:13 -0400 Received: from mail-pd0-f178.google.com ([209.85.192.178]:38434) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XEVWi-0001jJ-JP for qemu-devel@nongnu.org; Mon, 04 Aug 2014 23:35:04 -0400 Received: by mail-pd0-f178.google.com with SMTP id w10so512660pde.9 for ; Mon, 04 Aug 2014 20:35:04 -0700 (PDT) From: Ming Lei Date: Tue, 5 Aug 2014 11:33:10 +0800 Message-Id: <1407209598-2572-10-git-send-email-ming.lei@canonical.com> In-Reply-To: <1407209598-2572-1-git-send-email-ming.lei@canonical.com> References: <1407209598-2572-1-git-send-email-ming.lei@canonical.com> Subject: [Qemu-devel] [PATCH v1 09/17] dataplane: enable selective bypassing coroutine List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, Peter Maydell , Paolo Bonzini , Stefan Hajnoczi Cc: Kevin Wolf , Ming Lei , Fam Zheng , "Michael S. Tsirkin" This patch enables selective bypassing for the coroutine in bdrv_co_aio_rw_vector() if the image format is raw. With this patch, ~10% throughput improvement for raw image is observed in the VM based on server. Signed-off-by: Ming Lei --- hw/block/dataplane/virtio-blk.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c index c9a8cc2..a0732e3 100644 --- a/hw/block/dataplane/virtio-blk.c +++ b/hw/block/dataplane/virtio-blk.c @@ -30,6 +30,7 @@ struct VirtIOBlockDataPlane { bool started; bool starting; bool stopping; + bool raw_format; VirtIOBlkConf *blk; @@ -199,6 +200,8 @@ void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *blk, error_setg(&s->blocker, "block device is in use by data plane"); bdrv_op_block_all(blk->conf.bs, s->blocker); + s->raw_format = (raw_get_aio_fd(blk->conf.bs) >= 0); + *dataplane = s; } @@ -272,6 +275,10 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s) /* Kick right away to begin processing requests already in vring */ event_notifier_set(virtio_queue_get_host_notifier(vq)); + if (s->raw_format) { + bdrv_set_bypass_co(s->ctx, true); + } + /* Get this show started by hooking up our callbacks */ aio_context_acquire(s->ctx); aio_set_event_notifier(s->ctx, &s->host_notifier, handle_notify); @@ -303,6 +310,9 @@ void virtio_blk_data_plane_stop(VirtIOBlockDataPlane *s) vblk->obj_pool = NULL; + if (s->raw_format) { + bdrv_set_bypass_co(s->ctx, false); + } /* Sync vring state back to virtqueue so that non-dataplane request * processing can continue when we disable the host notifier below. */ -- 1.7.9.5