Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 28 Dec 2000 18:35:08 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 28 Dec 2000 18:34:58 -0500 Received: from brutus.conectiva.com.br ([200.250.58.146]:46831 "EHLO brutus.conectiva.com.br") by vger.kernel.org with ESMTP id ; Thu, 28 Dec 2000 18:34:43 -0500 Date: Thu, 28 Dec 2000 21:03:56 -0200 (BRDT) From: Rik van Riel To: Andi Kleen cc: "David S. Miller" , torvalds@transmeta.com, marcelo@conectiva.com.br, linux-kernel@vger.kernel.org Subject: Re: test13-pre5 In-Reply-To: <20001228235836.A25388@gruyere.muc.suse.de> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 28 Dec 2000, Andi Kleen wrote: > On Thu, Dec 28, 2000 at 02:33:07PM -0800, David S. Miller wrote: > > Date: Thu, 28 Dec 2000 23:17:22 +0100 > > From: Andi Kleen > > > > Would you consider patches for any of these points? > > > > To me it seems just as important to make sure struct page is > > a power of 2 in size, with the waitq debugging turned off this > > is true for both 32-bit and 64-bit hosts last time I checked. > > Why exactly a power of two ? To get rid of ->index ? Most likely to minimise the number of cache misses needed to access a complete page_struct. Then again, I guess 48 bytes would _also_ guarantee that we never need more than 2 cache misses to access every part of the page_struct. And the memory wasted in the page_struct may well be a bigger factor than the cache misses on lots of systems... (time for another CONFIG option? ;)) regards, Rik -- Hollywood goes for world dumbination, Trailer at 11. http://www.surriel.com/ http://www.conectiva.com/ http://distro.conectiva.com.br/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/