Re: 2.6.24-rc2: Network commit causes SLUB performance regression with tbench

From: Herbert Xu
Date: Wed Nov 14 2007 - 20:11:44 EST


On Wed, Nov 14, 2007 at 05:03:25PM -0800, Christoph Lameter wrote:
>
> Well this is likely the result of the SLUB regression. If you allocate an
> order 1 page then the zone locks need to be taken. SLAB queues the a
> couple of higher order pages and can so serve a couple of requests without
> going into the page allocator whereas SLUB has to go directly to the page
> allocator for allocate and free. I guess that needs fixing in the page
> allocator. Or do I need to add a mechanism to buffer higher order page
> allcoations to SLUB?

Actually this serves to discourage people from using high-order
allocations which IMHO is a good thing :)

Cheers,
--
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Email: Herbert Xu ~{PmV>HI~} <herbert@xxxxxxxxxxxxxxxxxxx>
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