From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Dillow Subject: Re: [PATCH] r8169: Reduce looping in the interrupt handler. Date: Mon, 31 Aug 2009 23:33:16 -0400 Message-ID: <1251775996.3345.5.camel@obelisk.thedillows.org> References: <1251294974.14241.9.camel@obelisk.thedillows.org> <1251295175.14241.11.camel@obelisk.thedillows.org> <20090826213024.GA20428@electric-eye.fr.zoreil.com> <20090827052423.GA1709@electric-eye.fr.zoreil.com> <20090827232024.GA30119@electric-eye.fr.zoreil.com> <1251422978.21865.2.camel@obelisk.thedillows.org> <20090830203735.GA24912@electric-eye.fr.zoreil.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Francois Romieu , Michael Riepe , Michael Buesch , Rui Santos , Michael B??ker , linux-kernel@vger.kernel.org, netdev@vger.kernel.org To: "Eric W. Biederman" Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Sun, 2009-08-30 at 13:53 -0700, Eric W. Biederman wrote: > Francois Romieu writes: > > > David Dillow : > > [...] > >> It'll be this weekend, but I can see cases where it can lock my chip up > >> -- they should be rare, but then I thought your case would be extremely > >> rare... > > > > I don't get it. > > > > Can you elaborate the relevant cases or give some sample scenarios for > > them ? > > I think David is referring to the fact that in the NAPI loop there is > nothing that acks everything. That was my concern, yes. I've not been able to reproduce my lockups under medium testing with Francois's patch applied, so I'm a little more comfortable with it. At the same time, I'm worried that the timing just changed enough to make it harder to trigger, as was the case when I did the patch IIRC. The kernel's interrupt handling changed in a manner that made it much easier to hit about that time. The testing I did in May pointed strongly at us failing to ACK an interrupt source, causing the MSI generation to stop, so I need to think about things some more.