From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Bjoern B. Brandenburg" Date: Fri, 09 May 2008 01:50:06 +0000 Subject: Re: enabling lockdep causes boot failure on a SUN T2000 Message-Id: <4823ADCE.4050009@email.unc.edu> List-Id: References: <48238125.7040900@email.unc.edu> In-Reply-To: <48238125.7040900@email.unc.edu> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: sparclinux@vger.kernel.org David Miller wrote: > From: "Bjoern B. Brandenburg" >> I've been having a hard time getting Linux (vanilla 2.6.24 and 2.6.25) >> to boot on our Niagara box. > > We know about this problem already. Thanks for reporting. > > This changeset below was meant to improve things, but t1000/t2000 > systems still get wedged. Thanks for the pointer. Based on your commit, I tried to disable stack trace support (with the intent to get at least some output in the event of deadlock) with the following patch: diff --git a/kernel/lockdep.c b/kernel/lockdep.c index e2c07ec..b468790 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -342,7 +342,9 @@ static int save_trace(struct stack_trace *trace) trace->skip = 3; - save_stack_trace(trace); + /* Work around: this doesn't work on the T2000. + * save_stack_trace(trace); + */ trace->max_entries = trace->nr_entries; I figured that if the flushes are the root cause, then this should take care of the problem. However, the kernel still doesn't boot. Is there anything else that I can disable to get a partially working lockdep? Thanks, Bjoern