From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 9 Nov 2007 12:13:32 -0800 From: Andrew Morton Subject: Re: [patch 2/2] x86_64: Configure stack size Message-Id: <20071109121332.7dd34777.akpm@linux-foundation.org> In-Reply-To: References: <20071107004357.233417373@sgi.com> <20071107004710.862876902@sgi.com> <20071107191453.GC5080@shadowen.org> <200711080012.06752.ak@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: ak@suse.de, apw@shadowen.org, linux-mm@kvack.org, travis@sgi.com List-ID: On Wed, 7 Nov 2007 16:42:04 -0800 (PST) Christoph Lameter wrote: > On Thu, 8 Nov 2007, Andi Kleen wrote: > > > > > > We seem to be growing two different mechanisms here for 32bit and 64bit. > > > This does seem a better option than that in 32bit CONFIG_4KSTACKS etc. > > > IMO when these two merge we should consolidate on this version. > > > > Best would be to not change it at all for 64bit for now. > > > > We can worry about the 16k CPU systems when they appear, but shorter term > > it would just lead to other crappy kernel code relying on large stacks when > > it shouldn't. > > Well we cannot really test these systems without these patches and when > they become officially available then its too late for merging. It doesn't take many 2kb cpumasks to use up a lot of stack. What else can we do? Change all sites to do some dynamic allocation if (NR_CPUS >= lots), I guess. As for timing: we might as well merge it now so that 2.6.25 has at least a chance of running on 16384-way. otoh, I doubt if anyone will actually ship an NR_CPUS=16384 kernel, so it isn't terribly pointful. So I'm wobbly. Could we please examine the alternatives before proceeding? Is there any plan in anyone's mind to fix this problem in a better but probably more intrusive fashion? -- 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/ . Don't email: email@kvack.org