From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764233AbXGNTmV (ORCPT ); Sat, 14 Jul 2007 15:42:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759847AbXGNTmO (ORCPT ); Sat, 14 Jul 2007 15:42:14 -0400 Received: from waste.org ([66.93.16.53]:36787 "EHLO waste.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761136AbXGNTmN (ORCPT ); Sat, 14 Jul 2007 15:42:13 -0400 Date: Sat, 14 Jul 2007 14:42:04 -0500 From: Matt Mackall To: Jesper Juhl Cc: Jeremy Fitzhardinge , Ray Lee , Linux Kernel Mailing List , William Lee Irwin III Subject: Re: [PATCH][RFC] 4K stacks default, not a debug thing any more...? Message-ID: <20070714194204.GB11166@waste.org> References: <200707111916.35036.jesper.juhl@gmail.com> <2c0942db0707112159v3ee2cd83i74759c7138e273f7@mail.gmail.com> <9a8748490707121324q3b3e6e65ye14ab8e7f089d999@mail.gmail.com> <4696C89E.4010002@goop.org> <9a8748490707121925w5fb22c0o61068f06d66d5845@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9a8748490707121925w5fb22c0o61068f06d66d5845@mail.gmail.com> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 13, 2007 at 04:25:56AM +0200, Jesper Juhl wrote: > On 13/07/07, Jeremy Fitzhardinge wrote: > >Jesper Juhl wrote: > >> If, on the other hand, we consider 4K stacks to be the superior > >> solution, then we should work to get all code fixed to be able to > >> handle it so that it's actually something distros will start to enable > >> so that we can eventually get rid of the 8K stack option alltogether. > >> Making 4K stacks default and no longer a debug option is just the > >> first step in that direction. > > > >First step is to apply wli's patch which makes separate interrupt stacks > >orthogonal to the 4K stack option. > > > Yes and no. If that will get things moving in the direction of > getting rid of the stack size as a config option, then I'm all for it. > But on the other hand it is my personal opinion that this is an area > where we should just make up our minds as to whether we want 4K or 8K > stacks and whether we want interrupt stacks or not, and then not have > it configurable at all. I believe the goal is 4K stacks + interrupt > stacks, so let's just aim for that and get rid of the configurability > of the damn thing - make a choice, make it work, make it be that > that's what we use and rid ourselves of the alternatives... There are two downsides to interrupt stacks: - an extra 4k/8k used per CPU - stack switch time Both of those are pretty minimal. And I'd be surprised if the latter was measurable. -- Mathematics is the supreme nostalgia of our time.