Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750806AbVKJM0a (ORCPT ); Thu, 10 Nov 2005 07:26:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750808AbVKJM0a (ORCPT ); Thu, 10 Nov 2005 07:26:30 -0500 Received: from smtp.osdl.org ([65.172.181.4]:58825 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1750806AbVKJM03 (ORCPT ); Thu, 10 Nov 2005 07:26:29 -0500 Date: Thu, 10 Nov 2005 04:26:13 -0800 From: Andrew Morton To: Ingo Molnar Cc: hugh@veritas.com, linux-kernel@vger.kernel.org, torvalds@osdl.org Subject: Re: [PATCH 01/15] mm: poison struct page for ptlock Message-Id: <20051110042613.7a585dec.akpm@osdl.org> In-Reply-To: <20051110120624.GB32672@elte.hu> References: <20051109181022.71c347d4.akpm@osdl.org> <20051109185645.39329151.akpm@osdl.org> <20051110120624.GB32672@elte.hu> X-Mailer: Sylpheed version 1.0.4 (GTK+ 1.2.10; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1052 Lines: 27 Ingo Molnar wrote: > > yuck. What is the real problem btw? Well. One problem is that spinlocks now take two words... But apart from that, the problem at hand is that we want to embed a spinlock in struct page, and the size of the spinlock varies a lot according to config. The only >wordsize version we really care about is CONFIG_PREEMPT, NR_CPUS >= 4. (which distros don't ship...) > AFAICS there's enough space for a > 2-word spinlock in struct page for pagetables. spinlocks get a lot bigger than that with CONFIG_DEBUG_SPINLOCK. > We really dont want to > rewrite spinlocks (or remove features) just to keep gcc 2.95 supported > for some more time. In fact, is there any 2.6 based distro that uses gcc > 2.95? I think some of the debian derivates might. But who knows? - 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/