Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762175AbXFDTtL (ORCPT ); Mon, 4 Jun 2007 15:49:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759617AbXFDTsy (ORCPT ); Mon, 4 Jun 2007 15:48:54 -0400 Received: from daemonizer.de ([87.230.16.230]:37992 "EHLO daemonizer.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753483AbXFDTsw (ORCPT ); Mon, 4 Jun 2007 15:48:52 -0400 From: Maximilian Engelhardt To: Ingo Molnar Subject: Re: iperf: performance regression (was b44 driver problem?) Date: Mon, 4 Jun 2007 21:47:59 +0200 User-Agent: KMail/1.9.7 Cc: Stephen Hemminger , Thomas Gleixner , Ulrich Drepper , Michael Buesch , linux-kernel , linux-wireless , Arnaldo Carvalho de Melo , Jeff Garzik , Gary Zambrano , netdev@vger.kernel.org, Andrew Morton References: <20070525172431.60affaca@freepuppy> <20070604105158.31ede1f5@freepuppy> <20070604193206.GA13271@elte.hu> In-Reply-To: <20070604193206.GA13271@elte.hu> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart1294756.CnZEpMUT4R"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Message-Id: <200706042148.02450.maxi@daemonizer.de> X-Spam-Score: -4.1 (----) X-Spam-Report: No, hits=-4.1 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.1.7-deb * -1.8 ALL_TRUSTED Passed through trusted hosts only via SMTP * -2.6 BAYES_00 BODY: Bayesian spam probability is 0 to 1% * [score: 0.0000] * 0.3 AWL AWL: From: address is in the auto white-list Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1674 Lines: 46 --nextPart1294756.CnZEpMUT4R Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On Monday 04 June 2007, Ingo Molnar wrote: > * Stephen Hemminger wrote: > > Yes, the following patch makes iperf work better than ever. But are > > other broken applications going to have same problem. Sounds like the > > old "who runs first" fork() problems. > > this is the first such app and really, and even for this app: i've been > frequently running iperf on -rt kernels for _years_ and never noticed > how buggy its 'locking' code was, and that it would under some > circumstances use up the whole CPU on high-res timers. I must admit I don't know much about that topic, but there is one thing I=20 don't understand. Why is iperf (even if it's buggy) able to use up the whol= e=20 cpu? I didn't run it as root but as my normal user so it should have limite= d=20 rights. Shouldn't the linux scheduler distribute cpu time among all running= =20 processes? Maxi --nextPart1294756.CnZEpMUT4R Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQBGZGxyOimwv528XGERAslBAKDFEN/kVetmUZatC669/yQ+Gds8LQCg0ce3 j/jrso2q5DkyFYTWaCF8fjw= =e1os -----END PGP SIGNATURE----- --nextPart1294756.CnZEpMUT4R-- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/