Re: [PATCH 2.6.20-rc4 0/4] futexes functionalities and improvements

From: Ulrich Drepper
Date: Tue Jan 16 2007 - 10:16:39 EST


Pierre Peiffer wrote:
> I've run this bench 1000 times with pipe and 800 groups.
> Here are the results:

This is not what I'm mostly concerned about. The patches create a
bottleneck since _all_ processes use the same resource. Plus, this code
has to be run on a machine with multiple processors to get RFOs into play.

So, please do this: on an SMP (4p or more) machine, rig the test so that
it runs quite a while. Then, in a script, start the program a bunch of
times, all in parallel. Have the script wait until all program runs are
done and time the time until the last program finishes.

--
â Ulrich Drepper â Red Hat, Inc. â 444 Castro St â Mountain View, CA â

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