virtio_blk: Drop unused request tracking list (f65ca1dc) · Commits · 戴 / test

Benchmark shows small performance improvement on fusion io device. Before: seq-read : io=1,024MB, bw=19,982KB/s, iops=39,964, runt= 52475msec seq-write: io=1,024MB, bw=20,321KB/s, iops=40,641, runt= 51601msec rnd-read : io=1,024MB, bw=15,404KB/s, iops=30,808, runt= 68070msec rnd-write: io=1,024MB, bw=14,776KB/s, iops=29,552, runt= 70963msec After: seq-read : io=1,024MB, bw=20,343KB/s, iops=40,685, runt= 51546msec seq-write: io=1,024MB, bw=20,803KB/s, iops=41,606, runt= 50404msec rnd-read : io=1,024MB, bw=16,221KB/s, iops=32,442, runt= 64642msec rnd-write: io=1,024MB, bw=15,199KB/s, iops=30,397, runt= 68991msec Signed-off-by:

Asias He <asias@redhat.com> Signed-off-by:

Rusty Russell <rusty@rustcorp.com.au>

drivers/block/virtio_blk.c

+0 −10

Original line number	Diff line number	Diff line
		@@ -29,9 +29,6 @@ struct virtio_blk
		/* The disk structure for the kernel. */
		struct gendisk *disk;

		/* Request tracking. */
		struct list_head reqs;

		mempool_t *pool;

		/* Process context for config space updates */
		@@ -55,7 +52,6 @@ struct virtio_blk

		struct virtblk_req
		{
		struct list_head list;
		struct request *req;
		struct virtio_blk_outhdr out_hdr;
		struct virtio_scsi_inhdr in_hdr;
		@@ -99,7 +95,6 @@ static void blk_done(struct virtqueue *vq)
		}

		__blk_end_request_all(vbr->req, error);
		list_del(&vbr->list);
		mempool_free(vbr, vblk->pool);
		}
		/* In case queue is stopped waiting for more buffers. */
		@@ -184,7 +179,6 @@ static bool do_req(struct request_queue q, struct virtio_blk vblk,
		return false;
		}

		list_add_tail(&vbr->list, &vblk->reqs);
		return true;
		}

		@@ -437,7 +431,6 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
		goto out_free_index;
		}

		INIT_LIST_HEAD(&vblk->reqs);
		spin_lock_init(&vblk->lock);
		vblk->vdev = vdev;
		vblk->sg_elems = sg_elems;
		@@ -591,9 +584,6 @@ static void __devexit virtblk_remove(struct virtio_device *vdev)
		vblk->config_enable = false;
		mutex_unlock(&vblk->config_lock);

		/* Nothing should be pending. */
		BUG_ON(!list_empty(&vblk->reqs));

		/* Stop all the virtqueues. */
		vdev->config->reset(vdev);

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