From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx164.postini.com [74.125.245.164]) by kanga.kvack.org (Postfix) with SMTP id 858246B0075 for ; Sun, 11 Dec 2011 18:05:15 -0500 (EST) Date: Mon, 12 Dec 2011 10:05:11 +1100 From: Dave Chinner Subject: Re: XFS causing stack overflow Message-ID: <20111211230511.GH14273@dastard> References: <20111209115513.GA19994@infradead.org> <20111209221956.GE14273__25752.826271537$1323469420$gmane$org@dastard> <20111210221345.GG14273@dastard> <20111211000036.GH24062@one.firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20111211000036.GH24062@one.firstfloor.org> Sender: owner-linux-mm@kvack.org List-ID: To: Andi Kleen Cc: Christoph Hellwig , linux-mm@kvack.org, xfs@oss.sgi.com, "Ryan C. England" On Sun, Dec 11, 2011 at 01:00:36AM +0100, Andi Kleen wrote: > > Where does the x86-64 do the interrupt stack switch? > > in entry_64.S > > > > > I know the x86 32 bit interrupt handler switches to an irq/softirq > > context stack, but the 64 bit one doesn't appear to. Indeed, > > arch/x86/kernel/irq_{32,64}.c are very different, and only the 32 > > bit irq handler switches to another stack to process the > > interrupts... > > x86-64 always used interrupt stacks and has used softirq stacks > for a long time. 32bit got to it much later (the only good > thing left from that 4k stack "experiment") Oh, it's hidden in the "SAVE_ARGS_IRQ" macro. But that happens before do_IRQ is called, so what is the do_IRQ call chain doing on this stack given that we've already supposed to have switched to the interrupt stack before do_IRQ is called? Cheers, Dave. -- Dave Chinner david@fromorbit.com -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org