Messages in this thread | | | Subject | Re: [cpuops inc_return V1 8/9] random: Use this_cpu_inc_return | From | Matt Mackall <> | Date | Mon, 06 Dec 2010 12:11:42 -0600 |
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On Mon, 2010-12-06 at 11:40 -0600, Christoph Lameter wrote: > plain text document attachment (cpuops_inc_return_random) > __this_cpu_inc can create a single instruction to do the same as > __get_cpu_var()++.
> - (__get_cpu_var(trickle_count)++ & 0xfff)) > + ((__this_cpu_inc_return(trickle_count) - 1) & 0xfff))
I see you've added a "- 1" to mimic the post-increment ++ semantic.
The goal of this code to add only 1 sample in every 4096, but we don't really care which, so this semantic isn't actually important here.
-- Mathematics is the supreme nostalgia of our time.
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