Subject: Re: [PATCH][RFC] network splice receive

From: Jens Axboe <[email-masked]>
Date: Thu, 7 Jun 2007 12:51:59 +0200

On Thu, Jun 07 2007, Evgeniy Polyakov wrote:
> On Wed, Jun 06, 2007 at 09:17:25AM +0200, Jens Axboe ([email-masked]) wrote:
> > > Some pages have zero reference counter here.
> > 
> > But it's somewhat annoying to get pages with zero reference counts
> > there, I wonder how that happens. I guess if the skb->data originated
> > from kmalloc() then we don't really know. The main intent there was just
> > to ensure the page wasn't going away, but clearly it's not good enough
> > to ensure that reuse isn't taking place.
> 
> What bout checking if page belongs to kmalloc cache (or any other cache
> via priviate pointers) and do not perform any kind of reference counting
> on them? I will play with this a bit later today.

That might work, but sounds a little dirty... But there's probably no
way around. Be sure to look at the #splice-net branch if you are playing
with this, I've updated it a number of times and fixed some bugs in
there. Notably it now gets the offset right, and handles fragments and
fraglist as well.

-- 
Jens Axboe