Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758627AbXFDQgU (ORCPT ); Mon, 4 Jun 2007 12:36:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755166AbXFDQgG (ORCPT ); Mon, 4 Jun 2007 12:36:06 -0400 Received: from www.osadl.org ([213.239.205.134]:39626 "EHLO mail.tglx.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751134AbXFDQgE (ORCPT ); Mon, 4 Jun 2007 12:36:04 -0400 Subject: Re: b44: regression in 2.6.22 (resend) From: Thomas Gleixner To: Stephen Hemminger Cc: Maximilian Engelhardt , Michael Buesch , linux-kernel , linux-wireless , Arnaldo Carvalho de Melo , Jeff Garzik , Gary Zambrano , netdev@vger.kernel.org, Andrew Morton In-Reply-To: <20070604090918.42386fbb@freepuppy> References: <20070525172431.60affaca@freepuppy> <200705281944.05030.maxi@daemonizer.de> <1180380230.3657.3.camel@chaos> <200706031826.06891.maxi@daemonizer.de> <1180939188.4404.5.camel@chaos> <20070604090918.42386fbb@freepuppy> Content-Type: text/plain Date: Mon, 04 Jun 2007 18:35:58 +0200 Message-Id: <1180974958.4404.24.camel@chaos> Mime-Version: 1.0 X-Mailer: Evolution 2.10.1 (2.10.1-4.fc7) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1527 Lines: 39 On Mon, 2007-06-04 at 09:09 -0700, Stephen Hemminger wrote: > > > I did the test with an 2.6.22-rc3-git4 kernel and the p54 driver built > > > external as module. > > > > Can you look at iperf to figure out, whether it does some weird timer > > stuff (high frequency interval timer or such) ? Either check the code or > > strace it. > > It is the receiver doing a tight loop doing gettimeofday/recv calls. > > > sendto(-1227715616, 0xc, 3085438964, 0, {...}, 3067249832) = 0 > gettimeofday({1180973726, 981615}, NULL) = 0 > gettimeofday({1180973726, 981751}, NULL) = 0 > futex(0x8055c64, 0x5 /* FUTEX_??? */, 1) = 1 > futex(0x8055c90, FUTEX_WAKE, 1) = 0 > recv(4, "\0\0\0\0\0\0\0\1\0\0\23\211\0\0\0\0\0\0\0\0\377\377\364"..., 8192, 0) = 8192 > gettimeofday({1180973726, 982754}, NULL) = 0 > recv(4, "\0\0\0\0\0\0\0\1\0\0\23\211\0\0\0\0\0\0\0\0\377\377\364"..., 8192, 0) = 8192 > gettimeofday({1180973726, 983790}, NULL) = 0 Well, gettimeofday() is not affected by the highres code, but > nanosleep({0, 0}, NULL) = 0 > nanosleep({0, 0}, NULL) = 0 is. The nanosleep call with a relative timeout of 0 returns immediately with highres enabled, while it sleeps at least until the next tick arrives when highres is off. Are there more of those stupid sleeps in the code ? tglx - 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/