From mboxrd@z Thu Jan 1 00:00:00 1970 From: William Lee Irwin III Date: Thu, 19 Aug 2004 14:12:13 +0000 Subject: Re: Patch - Sun4d SMP now boots Message-Id: <20040819141213.GM11200@holomorphy.com> List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: sparclinux@vger.kernel.org On Thu, Aug 19, 2004 at 02:32:47PM +0100, Chris Newport wrote: > I have now applied the patch posted to the list by Pasi Pirhonen > on 19Nov2003. This needs to be applied AFTER the patches from Thomas. > More work is needed to get rid of the previously reported compiler > warnings in the same function before this is fit to be submitted, but > I will have to leave that to those who understand what they are doing > This now boots and runs, but is horribly unstable. Okay, this is great news. I know the spin_lock_bh() is wrong, but it gets us to a point where we can actually do something and we actually have enough to reproduce all this. One major question is *WHY* spin_lock_bh() vs. spin_lock_irqsave() works. Only trouble there is that we can't see what happens after spin_lock_irqsave() very easily. One rather large possibility is that since disabling bh's doesn't disable interrupts, some smp_call_function() or similar that would deadlock if interrupts weren't disabled suddenly appears to work and/or works for some limited cases... This is in my queue also, though preferably some explanation of what's going on with this (e.g. the real issue, maybe a better fix) will happen instead. -- wli