Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753456AbYHZXwb (ORCPT ); Tue, 26 Aug 2008 19:52:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752194AbYHZXwV (ORCPT ); Tue, 26 Aug 2008 19:52:21 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:60340 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752184AbYHZXwU (ORCPT ); Tue, 26 Aug 2008 19:52:20 -0400 Date: Tue, 26 Aug 2008 16:51:52 -0700 (PDT) From: Linus Torvalds To: Adrian Bunk cc: Rusty Russell , "Alan D. Brunelle" , "Rafael J. Wysocki" , Linux Kernel Mailing List , Kernel Testers List , Andrew Morton , Arjan van de Ven , Ingo Molnar , linux-embedded@vger.kernel.org Subject: Re: [Bug #11342] Linux 2.6.27-rc3: kernel BUG at mm/vmalloc.c - bisected In-Reply-To: <20080826232411.GC11734@cs181140183.pp.htv.fi> Message-ID: References: <48B313E0.1000501@hp.com> <200808261111.19205.rusty@rustcorp.com.au> <20080826183051.GB10925@cs181140183.pp.htv.fi> <20080826205916.GB11734@cs181140183.pp.htv.fi> <20080826232411.GC11734@cs181140183.pp.htv.fi> User-Agent: Alpine 1.10 (LFD 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1626 Lines: 45 On Wed, 27 Aug 2008, Adrian Bunk wrote: > > > > We're much better off with a 1% code-size reduction than forcing big > > stacks on people. The 4kB stack option is also a good way of saying "if it > > works with this, then 8kB is certainly safe". > > You implicitely assume both would solve the same problem. I'm just saying that your logic doesn't hold water. If we can save kernel stack usage, then a 1% increase in kernel size is more than worth it. > While 4kB stacks are something we anyway never got 100% working What? Don't be silly. Linux _historically_ always used 4kB stacks. No, they are likely not usable on x86-64, but dammit, they should be more than usable on x86-32 still. > But I do not think the problem you'd solve with > -fno-inline-functions-called-once is big enough to warrant the size > increase it causes. You continually try to see the inlining as a single solution to one problem (debuggability, stack, whatever). The biggest problem with gcc inlining has always been that it has been _unpredictable_. It causes problems in many different ways. It has caused stability issues due to gcc versions doing random things. It causes the stack expansion. It makes stack traces harder for debugging, etc. If it was any one thing, I wouldn't care. But it's exactly the fact that it causes all these problems in different areas. Linus -- 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/