From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keith Owens Date: Fri, 22 Oct 2004 04:25:55 +0000 Subject: Converting ia64 kernel unwinder to lock free code Message-Id: <5907.1098419155@kao2.melbourne.sgi.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org MCA and INIT events are not irq safe, they can interrupt the kernel at any point, including with spin_lock_irqsave() set. We currently call the ia64 kernel unwinder from MCA and INIT handlers, which has the potential to deadlock or to return invalid results. I want to convert the kernel unwinder to be lock free, so it can be called from any state. That means no locks, and no calls to kernel sevices that might deadlock, including printk and kmalloc. Before I start on this task, are there any other plans for the kernel unwinder code? In the past davidm has hinted at replacing it with libunwind.