From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Walker Subject: Re: [PATCH] Don't sleep in oops_begin() Date: Mon, 17 Sep 2007 12:07:27 -0700 Message-ID: <1190056047.3253.104.camel@imap.mvista.com> References: <200709172012.21102.ak@suse.de> <200709172046.50850.ak@suse.de> <1190055244.3253.95.camel@imap.mvista.com> <200709172100.03279.ak@suse.de> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: mingo@elte.hu, Thomas Gleixner , linux-rt-users@vger.kernel.org To: Andi Kleen Return-path: Received: from gateway-1237.mvista.com ([63.81.120.158]:50285 "EHLO gateway-1237.mvista.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753563AbXIQTJl (ORCPT ); Mon, 17 Sep 2007 15:09:41 -0400 In-Reply-To: <200709172100.03279.ak@suse.de> Sender: linux-rt-users-owner@vger.kernel.org List-Id: linux-rt-users.vger.kernel.org On Mon, 2007-09-17 at 21:00 +0200, Andi Kleen wrote: > > Since it's all got "__" in the front, not good to use this method all > > over .. If you just need a real spinlock best to use > > DEFINE_RAW_SPINLOCK() unless your a special situation .. > > Oopsing is a special situation. Nobody knows if all the fancy infrastructure > lurking inside the other macros still works. In the case of spinlocks, real time just differs from the mainline kernel by make a spinlock_t into a mutex .. We know that's not going to work in this situation. The rest of the debugging added to spinlocks is mostly un-changed from mainline (like lockdep is still there).. So you should be able to use a regular mainline style spinlock_t for the die_lock, even with all the debugging .. The real time spinlock macros are pretty complex , but it's mostly compile related complexity that disappears when you run the kernel. Daniel