From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261577AbVGIQpE (ORCPT ); Sat, 9 Jul 2005 12:45:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261607AbVGIQpE (ORCPT ); Sat, 9 Jul 2005 12:45:04 -0400 Received: from chretien.genwebhost.com ([209.59.175.22]:9637 "EHLO chretien.genwebhost.com") by vger.kernel.org with ESMTP id S261577AbVGIQpB (ORCPT ); Sat, 9 Jul 2005 12:45:01 -0400 Date: Sat, 9 Jul 2005 09:44:55 -0700 From: randy_dunlap To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, akpm@osdl.org, arjanv@infradead.org, guichaz@gmail.com Subject: Re: [patch] compress the stack layout of do_page_fault(), x86 Message-Id: <20050709094455.0ef508e3.rdunlap@xenotime.net> In-Reply-To: <20050709152924.GA13492@elte.hu> References: <20050709144116.GA9444@elte.hu> <20050709152924.GA13492@elte.hu> Organization: YPO4 X-Mailer: Sylpheed version 1.0.5 (GTK+ 1.2.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-ClamAntiVirus-Scanner: This mail is clean X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - chretien.genwebhost.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [0 0] / [47 12] X-AntiAbuse: Sender Address Domain - xenotime.net X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 9 Jul 2005 17:29:24 +0200 Ingo Molnar wrote: | | Guillaume noticed a bug in the patch, si_signo should be used instead of | SIGSEGV. (doh) New patch below. | | Ingo | | ----- | | this patch pushes the creation of a rare signal frame (SIGBUS or | SIGSEGV) into a separate function, thus saving stackspace in the main | do_page_fault() stackframe. The effect is 132 bytes less of stack used | by the typical do_page_fault() invocation - resulting in a denser | cache-layout. | | (another minor effect is that in case of kernel crashes that come from a | pagefault, we add less space to the already existing frame, giving the | crash functions a slightly higher chance to do their stuff without | overflowing the stack.) | | (the changes also result in slightly cleaner code.) | | build and boot tested. Hi Ingo- Just to clarify this, "boot tested" does not mean that this changed code was tested, right? or do you have a test case that was tested? Thanks, --- ~Randy