Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932277AbVLPOMH (ORCPT ); Fri, 16 Dec 2005 09:12:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932274AbVLPOMG (ORCPT ); Fri, 16 Dec 2005 09:12:06 -0500 Received: from mailout.stusta.mhn.de ([141.84.69.5]:6162 "HELO mailout.stusta.mhn.de") by vger.kernel.org with SMTP id S932277AbVLPOMF (ORCPT ); Fri, 16 Dec 2005 09:12:05 -0500 Date: Fri, 16 Dec 2005 15:12:06 +0100 From: Adrian Bunk To: Zwane Mwaikambo Cc: Andrew Morton , linux-kernel@vger.kernel.org, arjan@infradead.org Subject: Re: [2.6 patch] i386: always use 4k stacks Message-ID: <20051216141206.GZ23349@stusta.de> References: <20051215212447.GR23349@stusta.de> <20051215140013.7d4ffd5b.akpm@osdl.org> <20051215223000.GU23349@stusta.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2209 Lines: 54 On Thu, Dec 15, 2005 at 05:49:45PM -0800, Zwane Mwaikambo wrote: > On Thu, 15 Dec 2005, Adrian Bunk wrote: > > > On Thu, Dec 15, 2005 at 02:00:13PM -0800, Andrew Morton wrote: > > > > > Supporting 8k stacks is a small amount of code and nobody has seen a need > > > to make changes in there for quite a long time. So there's little cost to > > > keeping the existing code. > > > > > > And the existing code is useful: > > > > > > a) people can enable it to confirm that their weird crash was due to a > > > stack overflow. > > > > > > b) If I was going to put together a maximally-stable kernel for a > > > complex server machine, I'd select 8k stacks. We're still just too > > > squeezy, and we've had too many relatively-recent overflows, and there > > > are still some really deep callpaths in there. > > > > a1) People turn off 4k stacks and never report the problem / noone > > really debugs and fixes the reported problem. > > > > Me threatening people with enabling 4k stacks for everyone already > > resulted in several fixes. > > How about this, we apply this patch and perhaps add some debug option to > enable 8k by changing THREAD_SIZE. This way we have the seperate interrupt > stacks and 8k stacks for when someone suspects a stack overflow. You can always manually change THREAD_SIZE using a text editor. My count of bug reports for problems with in-kernel code with 4k stacks after Neil's patch went into -mm is still at 0. Either there are no problems left or noone pays attention to them since disabling 4k stacks "fixed" the problem. And not having an option makes it more likely that we get reports for and people interested in fixes for the latter. cu Adrian -- "Is there not promise of rain?" Ling Tan asked suddenly out of the darkness. There had been need of rain for many days. "Only a promise," Lao Er said. Pearl S. Buck - Dragon Seed - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/