From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268017AbUHKKYc (ORCPT ); Wed, 11 Aug 2004 06:24:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268020AbUHKKYc (ORCPT ); Wed, 11 Aug 2004 06:24:32 -0400 Received: from imap.gmx.net ([213.165.64.20]:48049 "HELO mail.gmx.net") by vger.kernel.org with SMTP id S268017AbUHKKY3 (ORCPT ); Wed, 11 Aug 2004 06:24:29 -0400 X-Authenticated: #4512188 Message-ID: <4119F3D9.7040708@gmx.de> Date: Wed, 11 Aug 2004 12:24:25 +0200 From: "Prakash K. Cheemplavam" User-Agent: Mozilla Thunderbird 0.7.3 (X11/20040805) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Con Kolivas CC: spaminos-ker@yahoo.com, linux-kernel@vger.kernel.org, William Lee Irwin III Subject: Re: Scheduler fairness problem on 2.6 series (Attn: Nick Piggin and others) References: <20040811022143.4892.qmail@web13910.mail.yahoo.com> In-Reply-To: X-Enigmail-Version: 0.85.0.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Con Kolivas wrote: | I tried this on the latest staircase patch (7.I) and am not getting any | output from your script when tested up to 60 threads on my hardware. Can | you try this version of staircase please? | | There are 7.I patches against 2.6.8-rc4 and 2.6.8-rc4-mm1 | | http://ck.kolivas.org/patches/2.6/2.6.8/ Hi, I just updated to 2.6.8-rc4-ck2 and tried the two options interactive and compute. Is the compute stuff functional? I tried setting it to 1 within X and after that X wasn't usable anymore (meaning it looked like locked up, frozen/gone mouse cursor even). I managed to switch back to console and set it to 0 and all was OK again. The interactive to 0 setting helped me with runnign locally multiple processes using mpi. Nevertheless (only with interactive 1 regression to vanilla scheduler, else same) can't this be enhanced? Details: I am working on a load balancing class using mpi. For testing purpises I am running multiple processes on my machine. So for a given problem I can say, it needs x time to solve. Using more processes opn a single machine, this time (except communication and balancing overhead) shouldn't be much larger. Unfortunately this happens. Eg. a given probelm using two processes needs about 20 seconds to finish. But using 8 it already needs 47s (55s with interactiv set to 1). No, my balancing framework is quite good. On a real (small, even larger till 128 nodes tested) cluster overhead is just as low as 3% to 5%, ie. it scales quite linearly. Any idea how to tweak the staircase to get near the 20 seconds with more processes? Or is this rather a problem of mpich used locally? If you like I can send you my code to test (beware it is not that small). Cheers, Prakash -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.5 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFBGfPZxU2n/+9+t5gRApa1AJ9j82Aujwj/IoGLqvDsX29y/dLu/wCglvse bRV6zeWc+6z+ETl9Hxqleho= =Jay6 -----END PGP SIGNATURE-----