Re: Fast path efficiency (Re: [rfc][patch] dynamic data structure switching)

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To: Oleg Verych <olecom@...>
Cc: Nick Piggin <npiggin@...>, Linux Kernel Mailing List <linux-kernel@...>, David Miller <davem@...>, Paul McKenney <paulmck@...>
Date: Thursday, September 6, 2007 - 7:35 am

Oleg Verych <olecom@flower.upol.cz> writes:

In general it shouldn't matter at all on any reasonably 
modern CPU (let's say less than 10 years old) unless you do
it tens of thousands of times in a loop. Also gcc has reasonable
default heuristics for this kind of stuff anyways
(e.g. return NULL or return negative value is predicted
unlikely by default) 

Cache misses are far more important to care about because
they cost hundreds of cycles.

-Andi
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Messages in current thread:
[rfc][patch] dynamic data structure switching, Nick Piggin, (Sun Sep 2, 2:27 pm)
Re: [rfc][patch] dynamic data structure switching, Peter Zijlstra, (Mon Sep 10, 7:55 am)
Re: [rfc][patch] dynamic data structure switching, Nick Piggin, (Mon Sep 10, 9:39 am)
Re: [rfc][patch] dynamic data structure switching, Nick Piggin, (Sun Sep 2, 2:36 pm)
Re: Fast path efficiency (Re: [rfc][patch] dynamic data stru..., Andi Kleen, (Thu Sep 6, 7:35 am)