Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751077AbWHGFfU (ORCPT ); Mon, 7 Aug 2006 01:35:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751083AbWHGFfU (ORCPT ); Mon, 7 Aug 2006 01:35:20 -0400 Received: from ms-smtp-04.nyroc.rr.com ([24.24.2.58]:57490 "EHLO ms-smtp-04.nyroc.rr.com") by vger.kernel.org with ESMTP id S1751077AbWHGFfT (ORCPT ); Mon, 7 Aug 2006 01:35:19 -0400 Date: Mon, 7 Aug 2006 01:34:56 -0400 (EDT) From: Steven Rostedt X-X-Sender: rostedt@gandalf.stny.rr.com To: Theodore Tso cc: David Miller , mchan@broadcom.com, herbert@gondor.apana.org.au, LKML , netdev@vger.kernel.org, Thomas Gleixner , Ingo Molnar Subject: Re: [PATCH -rt DO NOT APPLY] Fix for tg3 networking lockup In-Reply-To: <20060803235326.GC7894@thunk.org> Message-ID: References: <1154630207.3117.17.camel@rh4> <20060803201741.GA7894@thunk.org> <20060803.144845.66061203.davem@davemloft.net> <20060803235326.GC7894@thunk.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2108 Lines: 45 On Thu, 3 Aug 2006, Theodore Tso wrote: > On Thu, Aug 03, 2006 at 02:48:45PM -0700, David Miller wrote: > > > eth0: Tigon3 [partno(BCM95704s) rev 2100 PHY(serdes)] (PCIX:100MHz:64-bit) 10/100/1000BaseT Ethernet 00:14:5e:86:44:24 > > > > The 5704 chip will set TG3_FLAG_TAGGED_STATUS, and therefore > > doesn't need the periodic poking done by tg3_timer(). > > Hmm.... all I can say is that I could reliably knock the box off the > network by running a four processes that tied up all CPU's at high > real-time priorities, and after I applied the horrible hack that > guaranteed that tg3_timer() was run every 0.128 seconds, the system > stayed on the network. I'm not sure why, but it did fix the problem. > > Any suggestions on how I could figure out what was really going on and > what would be a better fix would be greatly appreciated. > Ted, I took a quick look at the tg3 driver and that timer interrupt as well have read this thread. My suggestion would be to separate that tg3_timer into 4 different timers, which is what it actually looks like. One I believe (the first one) is an actual timeout and the other three are timers that are expected to be triggered everytime (watchdog like: at 1 second, 2 seconds and 3 seconds) and thus should be converted into a hrtimers that goes off when expected then having some crazy accounting thing in one timer. I don't fully understand the ASF part here, and if it definitely needs to go off then set that timer with the highest prio. I've ask Thomas to add a way to add a hrtimer with a given prio instead of always taking the current->normal_prio. But until he does that, you can do a hack of changing the current prio to something very high (like 99) then start the timer, and then lower the prio back to what it was. This is a hack, but it might lead to a better solution in the future. -- Steve - 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/