From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Mundt Date: Thu, 07 May 2009 09:19:06 +0000 Subject: Re: 2.6.30-rc4-git: timer-related oops Message-Id: <20090507091906.GA26125@linux-sh.org> List-Id: References: <20090504091430.GA30660@linux-sh.org> In-Reply-To: <20090504091430.GA30660@linux-sh.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-sh@vger.kernel.org On Tue, May 05, 2009 at 07:44:48AM +0200, Manuel Lauss wrote: > On Mon, May 04, 2009 at 11:41:38PM +0900, Paul Mundt wrote: > > On Mon, May 04, 2009 at 04:14:46PM +0200, Manuel Lauss wrote: > > > On Mon, May 04, 2009 at 11:15:23AM +0200, Manuel Lauss wrote: > > > > Hello! > > > > > > > > Current -git (and a few revisions before that) oops when kernel tries to > > > > mount nfsroot. Anyone else seeing this? (system is SH7760; I disabled > > > > almost all of my platform code to rule out a screwup on my part. The code > > > > works on 2.6.29). > > > > > > Gaah, found it: CONFIG_4KSTACKS=y is the culprit. Removing it gives me a > > > nicely working system again. > > > > > > Sorry for the noise! > > > > > That is interesting, I run with 4k stacks all the time without incident > > on most configurations, with ample space to spare. Have you tried turning > > on stack usage reporting to see where it is all going? > > There are no warnings regarding stack overflows, and all in-kernel stack > users have plenty (>P%) stack space left. > > The _real_ culprit is actually CONFIG_IRQSTACKS=y; 4k stacks on its own is > fine, but with irqstacks enabled the kernel blows up with random oopses as > soon as it goes on to start the init process. > It looks like there is still some stack corruption going on here, I will have to debug it some more. I've added a depends on BROKEN for now so this doesn't get accidentally selected.