Date: Thu, 18 Mar 2004 17:56:54 -0800
From: Paul Jackson <pj@sgi.com>
To: colpatch@us.ibm.com
Cc: linux-kernel@vger.kernel.org, mbligh@aracnet.com, akpm@osdl.org,
       wli@holomorphy.com, haveblue@us.ibm.com, hch@infradead.org
Subject: Re: [PATCH] Introduce nodemask_t ADT [0/7]
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> These (cpumask_t/nodemask_t) are nice because they are
> optimized for edge cases (UP for cpumask_t and Non-NUMA for nodemask_t)
> as well as for long mask cases (passing by structs reference). 

When I looked at the assembly code generated on my one lung i386 box for
native gcc 3.3.2, it looked pretty good (to my untrained eye) using a
struct of an array of unsigned longs, both for the single unsigned long
(<= 32 bits) and multiple unsigned long cases.

Except for the sparc64 guys and their friends who disparage passing
structs on the stack, I conjecture that the single implementation of a
struct of an array of unsigned longs is nearly ideal for all
architectures.

... go ahead ... prove me wrong.  It probably won't be hard ;).

-- 
                          I won't rest till it's the best ...
                          Programmer, Linux Scalability
                          Paul Jackson <pj@sgi.com> 1.650.933.1373
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