Re: [PATCH 5/8] fcoe: reduces lock cost when adding a new skb to fcoe_pending_queue

James Bottomley
2009-05-06T18:09:26Z

On Wed, 2009-05-06 at 10:52 -0700, Robert Love wrote:
> From: Vasu Dev <vasu.dev@intel.com>
>
> Currently fcoe_pending_queue.lock held twice for every new skb
> adding to this queue when already least one pkt is pending in this
> queue and that is not uncommon once skb pkts starts getting queued
> here upon fcoe_start_io => dev_queue_xmit failure.
>
> This patch moves most fcoe_pending_queue logic to fcoe_check_wait_queue
> function, this new logic grabs fcoe_pending_queue.lock only once to
> add a new skb instead twice as used to be.
>
> I think after this patch call flow around fcoe_check_wait_queue
> calling in fcoe_xmit is bit simplified with modified
> fcoe_check_wait_queue function taking care of adding and
> removing pending skb in one function.

This isn't really a -rc4 bug fix, is it? It reads a lot more like a
feature enhancement that was given a bug like description.

James