Re: [PATCH] xen-blkfront: switch from llist to list

["Roger Pau Monné" <roger.pau@citrix.com>]

On 15/02/13 19:56, Konrad Rzeszutek Wilk wrote:
>> Should be backported to 3.8 stable.
> 
> Lets do one thing at a time.
> 
> The patch I have in the tree (and that I've asked Jens to pull for 3.9 - so
> he might have already in his tree) is the old hybrid where we still use llist
> but change the loop from 'for' to 'while'.
> 
> This is the stable/for-jens-3.8 tree in git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git 
> 
> Could you rebase your patch on top of that tree and just simplify the loop?
> 
> Sorry about the mess about this - but I had already pulled the trigger
> so to say - hoping that Jens would pull the tree and do a git pull to Linus.
> 
> And you are absolutly sure that we don't need any extra locking when switching
> over to list_head? Say if blkif_completion is called while we are
> processing in blkif_queue_request and doing ?

Will recheck it, but blkif_completition is called with the io_lock hold,
as does blkif_queue_request (I've added extra assert_spin_locked before
every list modification).