linux-kernel - Re: BFS vs. mainline scheduler benchmarks and measurements

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20090910110348.GK18599@kernel.dk>
Date:	Thu, 10 Sep 2009 13:03:48 +0200
From:	Jens Axboe <jens.axboe@...cle.com>
To:	Con Kolivas <kernel@...ivas.org>
Cc:	Nikos Chantziaras <realnc@...or.de>, Ingo Molnar <mingo@...e.hu>,
	Mike Galbraith <efault@....de>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	linux-kernel@...r.kernel.org
Subject: Re: BFS vs. mainline scheduler benchmarks and measurements

On Thu, Sep 10 2009, Con Kolivas wrote:
> > It probably just means that latt isn't a good measure of the problem.
> > Which isn't really too much of a surprise.
> 
> And that's a real shame because this was one of the first real good attempts 
> I've seen to actually measure the difference, and I thank you for your 
> efforts Jens. I believe the reason it's limited is because all you're 
> measuring is time from wakeup and the test app isn't actually doing any work. 
> The issue is more than just waking up as fast as possible, it's then doing 
> some meaningful amount of work within a reasonable time frame as well. What 
> the "meaningful amount of work" and "reasonable time frame" are, remains a 
> mystery, but I guess could be added on to this testing app.

Here's a quickie addition that adds some work to the threads. The
latency measure is now 'when did I wake up and complete my work'. The
default work is filling a buffer with pseudo random data and then
compressing it with zlib. Default is 64kb of data, can be adjusted with
-x. -x0 turns off work processing.

-- 
Jens Axboe


View attachment "latt.c" of type "text/x-csrc" (11246 bytes)