RE: [PATCH] SCSI driver for VMware's virtual HBA.

[Chetan . Loke]

Alok,


> +static int __devinit pvscsi_allocate_rings(struct pvscsi_adapter
> *adapter)
> +{
> +	adapter->rings_state = pci_alloc_consistent(adapter->dev, PAGE_SIZE,
> +						    &adapter->ringStatePA);
> +	if (!adapter->rings_state)
> +		return -ENOMEM;
> +
> +	adapter->req_pages = min(PVSCSI_MAX_NUM_PAGES_REQ_RING,
> +				 pvscsi_ring_pages);
> +	adapter->req_depth = adapter->req_pages
> +					* PVSCSI_MAX_NUM_REQ_ENTRIES_PER_PAGE;
> +	adapter->req_ring = pci_alloc_consistent(adapter->dev,
> +						 adapter->req_pages * PAGE_SIZE,
> +						 &adapter->reqRingPA);
> +	if (!adapter->req_ring)
> +		return -ENOMEM;
> +
> +	adapter->cmp_pages = min(PVSCSI_MAX_NUM_PAGES_CMP_RING,
> +				 pvscsi_ring_pages);
> +	adapter->cmp_ring = pci_alloc_consistent(adapter->dev,
> +						 adapter->cmp_pages * PAGE_SIZE,
> +						 &adapter->cmpRingPA);
> +	if (!adapter->cmp_ring)
> +		return -ENOMEM;
> +
> +	BUG_ON(adapter->ringStatePA & ~PAGE_MASK);
> +	BUG_ON(adapter->reqRingPA   & ~PAGE_MASK);
> +	BUG_ON(adapter->cmpRingPA   & ~PAGE_MASK);
> +
> +	if (!adapter->use_msg)
> +		return 0;
> +
> +	adapter->msg_pages = min(PVSCSI_MAX_NUM_PAGES_MSG_RING,
> +				 pvscsi_msg_ring_pages);
> +	adapter->msg_ring = pci_alloc_consistent(adapter->dev,
> +						 adapter->msg_pages * PAGE_SIZE,
> +						 &adapter->msgRingPA);
> +	if (!adapter->msg_ring)
> +		return -ENOMEM;
> +	BUG_ON(adapter->msgRingPA & ~PAGE_MASK);
> +
> +	return 0;
> +}
> +

I understand the emulation etc. But I see that this function isn't allocating multiple rings right? Didn't see any performance benefits?



Chetan




--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/