From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Ml09p-0001vh-SX for qemu-devel@nongnu.org; Tue, 08 Sep 2009 08:50:49 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1Ml09k-0001rb-CP for qemu-devel@nongnu.org; Tue, 08 Sep 2009 08:50:48 -0400 Received: from [199.232.76.173] (port=46223 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Ml09k-0001rT-4M for qemu-devel@nongnu.org; Tue, 08 Sep 2009 08:50:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:23505) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1Ml09j-0003L2-G4 for qemu-devel@nongnu.org; Tue, 08 Sep 2009 08:50:43 -0400 Received: from int-mx04.intmail.prod.int.phx2.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.17]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id n88CofxU001722 for ; Tue, 8 Sep 2009 08:50:41 -0400 From: Kevin Wolf Date: Tue, 8 Sep 2009 14:49:32 +0200 Message-Id: <1252414172-25721-3-git-send-email-kwolf@redhat.com> In-Reply-To: <1252414172-25721-1-git-send-email-kwolf@redhat.com> References: <1252414172-25721-1-git-send-email-kwolf@redhat.com> Subject: [Qemu-devel] [PATCH v2 2/2] virtio-blk: Use bdrv_aio_multiwrite List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Kevin Wolf It is quite common for virtio-blk to submit more than one write request in a row to the qemu block layer. Use bdrv_aio_multiwrite to allow block drivers to optimize its handling of the requests. Signed-off-by: Kevin Wolf --- hw/virtio-blk.c | 50 ++++++++++++++++++++++++++++++++++++++++++-------- 1 files changed, 42 insertions(+), 8 deletions(-) diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c index c160246..5c88c12 100644 --- a/hw/virtio-blk.c +++ b/hw/virtio-blk.c @@ -252,15 +252,40 @@ static void virtio_blk_handle_scsi(VirtIOBlockReq *req) } #endif /* __linux__ */ -static void virtio_blk_handle_write(VirtIOBlockReq *req) +static void do_multiwrite(BlockDriverState *bs, BlockRequest *blkreq, + int num_writes) { - BlockDriverAIOCB *acb; + int i, ret; + ret = bdrv_aio_multiwrite(bs, blkreq, num_writes); + + if (ret != 0) { + for (i = 0; i < num_writes; i++) { + if (blkreq[i].error) { + virtio_blk_req_complete(blkreq[i].opaque, VIRTIO_BLK_S_IOERR); + } + } + } +} - acb = bdrv_aio_writev(req->dev->bs, req->out->sector, &req->qiov, - req->qiov.size / 512, virtio_blk_rw_complete, req); - if (!acb) { - virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR); +static void virtio_blk_handle_write(BlockRequest *blkreq, int *num_writes, + VirtIOBlockReq *req, BlockDriverState **old_bs) +{ + if (req->dev->bs != *old_bs || *num_writes == 32) { + if (*old_bs != NULL) { + do_multiwrite(*old_bs, blkreq, *num_writes); + } + *num_writes = 0; + *old_bs = req->dev->bs; } + + blkreq[*num_writes].sector = req->out->sector; + blkreq[*num_writes].nb_sectors = req->qiov.size / 512; + blkreq[*num_writes].qiov = &req->qiov; + blkreq[*num_writes].cb = virtio_blk_rw_complete; + blkreq[*num_writes].opaque = req; + blkreq[*num_writes].error = 0; + + (*num_writes)++; } static void virtio_blk_handle_read(VirtIOBlockReq *req) @@ -278,6 +303,9 @@ static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq) { VirtIOBlock *s = to_virtio_blk(vdev); VirtIOBlockReq *req; + BlockRequest blkreq[32]; + int num_writes = 0; + BlockDriverState *old_bs = NULL; while ((req = virtio_blk_get_request(s))) { if (req->elem.out_num < 1 || req->elem.in_num < 1) { @@ -299,13 +327,18 @@ static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq) } else if (req->out->type & VIRTIO_BLK_T_OUT) { qemu_iovec_init_external(&req->qiov, &req->elem.out_sg[1], req->elem.out_num - 1); - virtio_blk_handle_write(req); + virtio_blk_handle_write(blkreq, &num_writes, req, &old_bs); } else { qemu_iovec_init_external(&req->qiov, &req->elem.in_sg[0], req->elem.in_num - 1); virtio_blk_handle_read(req); } } + + if (num_writes > 0) { + do_multiwrite(old_bs, blkreq, num_writes); + } + /* * FIXME: Want to check for completions before returning to guest mode, * so cached reads and writes are reported as quickly as possible. But @@ -324,7 +357,8 @@ static void virtio_blk_dma_restart_bh(void *opaque) s->rq = NULL; while (req) { - virtio_blk_handle_write(req); + bdrv_aio_writev(req->dev->bs, req->out->sector, &req->qiov, + req->qiov.size / 512, virtio_blk_rw_complete, req); req = req->next; } } -- 1.6.2.5