Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 9 Aug 2002 10:02:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 9 Aug 2002 10:02:53 -0400 Received: from dsl-213-023-043-103.arcor-ip.net ([213.23.43.103]:53387 "EHLO starship") by vger.kernel.org with ESMTP id ; Fri, 9 Aug 2002 10:02:52 -0400 Content-Type: text/plain; charset=US-ASCII From: Daniel Phillips To: Andrew Morton , Anton Blanchard Subject: Re: fix CONFIG_HIGHPTE Date: Fri, 9 Aug 2002 16:07:24 +0200 X-Mailer: KMail [version 1.3.2] Cc: William Lee Irwin III , linux-kernel@vger.kernel.org, riel@surriel.com References: <20020806231522.GJ6256@holomorphy.com> <20020807010752.GC6343@krispykreme> <3D508C83.3A78CC58@zip.com.au> In-Reply-To: <3D508C83.3A78CC58@zip.com.au> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Message-Id: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1340 Lines: 33 On Wednesday 07 August 2002 04:57, Andrew Morton wrote: > Anton Blanchard wrote: > > On ppc64 shared pagetables will require significant changes to the way > > we handle the hardware hashtable. So add that to the "more and more crap > > in there to support these pte_chains" > > Last I heard, pagetable sharing wasn't working out too well > because they all get unshared. That's only when you fork from a process with a minimal amount of VM mapped, such as bash, which has 3 page tables allocated to it, all of which get unshared. The situation is entirely different if you fork from a process that has malloced more than a few meg, or beaten on a large mmap. Page table sharing turns in a significant win there. > > Will shared pagetables be a requirement or can we turn it on per arch? > > It's doubtful if per-arch would be an option. It's currently expressed as a config option. As it's purely an optimization there's no reason to do otherwise. Disabling it per-arch should be trivial. > - We'll continue to suck for the University workload. That seems likely ;-) -- Daniel - 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/