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From: John Baldwin <jhb@freebsd.org>
To: freebsd-arch@freebsd.org
Subject: Re: Malloc alignment in libstand / loader(8)
Date: Wed, 05 Feb 2014 08:29:19 -0500
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 (bigwig.baldwin.cx); Wed, 05 Feb 2014 14:28:30 -0500 (EST)
Cc: Ian Lepore <ian@freebsd.org>
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On Tuesday, February 04, 2014 09:55:34 PM Ian Lepore wrote:
> On newer ARM chips, the device drivers used by loader(8) require that
> I/O buffers be aligned on cache line sized boundaries.  The drivers are
> part of u-boot which serves as a sort of load-time bios.
> 
> Attached is a patch that sets the malloc alignment in libstand to 64
> bytes when compiled on ARM, and leaves it at 16 bytes for all other
> platforms.  If there are no objections I'd like to commit this soon.
> 
> I've tested this on ARM, but have no way to test it on other platforms.
> The changes should be a no-op on other platforms.

I think this looks fine, but perhaps use CTASSERT() instead of rolling your 
own?  (I would say to use _Static_assert(), but I don't think that works with 
our old GCC)

-- 
John Baldwin