virtio_blk: Drop unused request tracking list

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>
This commit is contained in:
Asias He 2012-03-30 11:24:10 +08:00 committed by Rusty Russell
parent b79d866c8b
commit f65ca1dc6a

View File

@ -29,9 +29,6 @@ struct virtio_blk
/* The disk structure for the kernel. */ /* The disk structure for the kernel. */
struct gendisk *disk; struct gendisk *disk;
/* Request tracking. */
struct list_head reqs;
mempool_t *pool; mempool_t *pool;
/* Process context for config space updates */ /* Process context for config space updates */
@ -55,7 +52,6 @@ struct virtio_blk
struct virtblk_req struct virtblk_req
{ {
struct list_head list;
struct request *req; struct request *req;
struct virtio_blk_outhdr out_hdr; struct virtio_blk_outhdr out_hdr;
struct virtio_scsi_inhdr in_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); __blk_end_request_all(vbr->req, error);
list_del(&vbr->list);
mempool_free(vbr, vblk->pool); mempool_free(vbr, vblk->pool);
} }
/* In case queue is stopped waiting for more buffers. */ /* 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; return false;
} }
list_add_tail(&vbr->list, &vblk->reqs);
return true; return true;
} }
@ -437,7 +431,6 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
goto out_free_index; goto out_free_index;
} }
INIT_LIST_HEAD(&vblk->reqs);
spin_lock_init(&vblk->lock); spin_lock_init(&vblk->lock);
vblk->vdev = vdev; vblk->vdev = vdev;
vblk->sg_elems = sg_elems; vblk->sg_elems = sg_elems;
@ -591,9 +584,6 @@ static void __devexit virtblk_remove(struct virtio_device *vdev)
vblk->config_enable = false; vblk->config_enable = false;
mutex_unlock(&vblk->config_lock); mutex_unlock(&vblk->config_lock);
/* Nothing should be pending. */
BUG_ON(!list_empty(&vblk->reqs));
/* Stop all the virtqueues. */ /* Stop all the virtqueues. */
vdev->config->reset(vdev); vdev->config->reset(vdev);