Subject: Re: [PATCH 07/12] use a dynamic pool of sk_buffs to keep up with fast targets

From: Matt Mackall <[email-masked]>
Date: Tue, 3 Jul 2007 13:45:33 -0500

On Mon, Jul 02, 2007 at 09:40:36PM -0700, David Miller wrote:
> From: Andrew Morton <[email-masked]>
> Date: Mon, 2 Jul 2007 21:36:36 -0700
> 
> > My initial thought is that if there is a legitimate need for this
> > new capability then it should be made available to other parts of
> > the kernel rather than being private to the AEO driver.
> 
> Absolutely.
> 
> We even used to have something like this on a per-cpu basis but using
> generic SLAB is so much better for caching and NUMA that we got rid of
> that.
> 
> Every sk_buff private "quicklist" pool implementation you
> see should essentially be NAK'd from the get go, it's
> meaningless and if it's really needed one should investigate
> why SKB allocations become such a problem instead of papering
> over the issue. :-)

This is in the VM write-back path. SLAB is insufficient to avoid
deadlock.

-- 
Mathematics is the supreme nostalgia of our time.