Re: [PATCH 1/3] IB/ehca: Replace vmalloc with kmalloc

From: Stefan Roscher
Date: Tue Apr 28 2009 - 12:03:42 EST


On Tuesday 28 April 2009 05:12:51 pm Dave Hansen wrote:
> On Tue, 2009-04-21 at 17:16 +0200, Stefan Roscher wrote:
> > From: Anton Blanchard <antonb at au1.ibm.com>
> >
> > To improve performance of driver ressource allocation,
> > replace the vmalloc() call with kmalloc().
>
> Just curious, but how big are these allocations? Why was vmalloc() even
> ever used if we know they'll be small?
>
> -- Dave
>
>

The theoretical maximum size can be 512k, but for common queue pairs
less than 128k is used.Because of the theoretical maximum we implemented
vmalloc() first, but recognized a huge performance impact.

-- Stefan

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