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From: Rusty Russell <rusty@rustcorp.com.au>
To: Mike Travis <travis@sgi.com>
Subject: Re: [RFC] CPUMASK: proposal for replacing cpumask_t
Date: Sat, 13 Sep 2008 08:02:59 +1000
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Cc: Ingo Molnar <mingo@elte.hu>, Peter Zijlstra <peterz@infradead.org>,
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       David Miller <davem@davemloft.net>, Eric Dumazet <dada1@cosmosbay.com>,
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       Andi Kleen <andi@firstfloor.org>
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On Saturday 13 September 2008 00:28:56 Mike Travis wrote:
> Rusty Russell wrote:
> > I'm yet to be convinced that we really need to allocate cpumasks in any
> > fast paths.  And if not, we should simply allocate them everywhere.  I'd
> > rather see one #ifdef around a place where we can show a perf issue.
>
> Using a typedef came from Linus, and the idea is basically if NR_CPUS fits
> into a long, then it's carried as an array of one (ie., local variable).

Sure it's clever.  ie. nice and confusing.

But do we have any code paths where we care?  Unless we do, let's just keep it 
simple...

Cheers,
Rusty.