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Date: Mon, 17 Jul 2006 09:31:49 +0300
From: Muli Ben-Yehuda <muli@il.ibm.com>
To: Jeremy Kerr <jk@ozlabs.org>
Subject: Re: [PATCH] powerpc: simplify dma_ops bug conditions
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On Mon, Jul 17, 2006 at 01:55:09PM +1000, Jeremy Kerr wrote:

> No, it's not really necessary, more a style thing. The BUG_ON only adds 
> an extra 3 instructions (subfic, addi and tdnei), which should be tiny 
> compared to the indirect branch.

When we were submitting a patch to add a
BUG_ON(!valid_dma_data_direction(dir)) to x86-64's DMA-API, Jeff
Garzik was vehemently opposed to adding a few instructions to "one of
the hottest paths in the kernel".

Cheers,
Muli