Re: [PATCH] virtio-blk: allow more than one in-flight request

[Christian Borntraeger <borntraeger@de.ibm.com>]

Am Donnerstag, 27. März 2008 schrieb Marcelo Tosatti:
> 
> Allow more than one in-flight request in the virtio ring. This allows
> the host driver to submit requests in parallel.
[...]
> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> index 3b1a68d..5bb041f 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
[...]
> @@ -202,7 +204,8 @@ static int virtblk_probe(struct virtio_device *vdev)
>  		goto out_free_vblk;
>  	}
> 
> -	vblk->pool = mempool_create_kmalloc_pool(1,sizeof(struct virtblk_req));
> +	vblk->pool = mempool_create_kmalloc_pool(VIRTIO_BLK_POOL_SIZE,
> +                        sizeof(struct virtblk_req));
>  	if (!vblk->pool) {
>  		err = -ENOMEM;
>  		goto out_free_vq;
[...]

Huh? I dont understand. You only change the number of pre-allocated pool 
entries. mempool_alloc should allow several allocations, even with 1 as 
initialization value. The pre-initialized value is only for oom situations. 
No?

Christian

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