Messages in this thread |  | | | Subject | Re: [RFC PATCH 5/6] implement per-cpu&per-domain state machine call_srcu() | | From | Peter Zijlstra <> | | Date | Tue, 06 Mar 2012 16:38:18 +0100 |
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On Tue, 2012-03-06 at 23:17 +0800, Lai Jiangshan wrote: > On Tue, Mar 6, 2012 at 6:58 PM, Peter Zijlstra <peterz@infradead.org> wrote: > > On Tue, 2012-03-06 at 17:57 +0800, Lai Jiangshan wrote: > >> /* > >> + * 'return left < right;' but handle the overflow issues. > >> + * The same as 'return (long)(right - left) > 0;' but it cares more. > > > > About what? And why? We do the (long)(a - b) thing all over the kernel, > > why would you care more? > > @left is constants of the callers(callbacks's snapshot), @right > increases very slow. > if (long)(right - left) is a big negative, we have to wait for a long > time in this kinds of overflow. > this kinds of overflow can not happen in this safe_less_than()
I'm afraid I'm being particularly dense, but what?!
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