Message-ID: <53BAC676.5030804@redhat.com>
Date: Mon, 07 Jul 2014 18:10:30 +0200
From: Paolo Bonzini <pbonzini@redhat.com>
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To: Peter Zijlstra <peterz@infradead.org>
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Subject: Re: [PATCH 05/11] qspinlock: Optimize for smaller NR_CPUS
References: <20140615124657.264658593@chello.nl> <20140615130153.483502389@chello.nl> <53A17A88.7090705@redhat.com> <20140707143503.GS6758@twins.programming.kicks-ass.net> <53BAB7E1.4010506@redhat.com> <20140707153552.GE19379@twins.programming.kicks-ass.net>
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Il 07/07/2014 17:35, Peter Zijlstra ha scritto:
>> > Unlike the change in patch 4, clear_pending_set_locked doesn't change how
>> > qspinlock moves from a state to the next.
> True, but its where we start to break up into smaller functions. And the
> only reason we break them out is because we'll get different
> implementations depending on NR_CPUS.
>
> So we can view the breakout of xchg_tail and clear_and_set_pending as
> preparatory work for introducing the NR_CPUS thing.

That's a different reasoning, but it's fine by me too.

Paolo
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