Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 13 Sep 2002 01:36:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 13 Sep 2002 01:36:18 -0400 Received: from franka.aracnet.com ([216.99.193.44]:40348 "EHLO franka.aracnet.com") by vger.kernel.org with ESMTP id ; Fri, 13 Sep 2002 01:36:17 -0400 Date: Thu, 12 Sep 2002 22:38:58 -0700 From: "Martin J. Bligh" Reply-To: "Martin J. Bligh" To: Andrew Morton , William Lee Irwin III cc: Dave Hansen , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH] per-zone kswapd process Message-ID: <619179322.1031870337@[10.10.2.3]> In-Reply-To: <3D817BC8.785F5C44@digeo.com> References: <3D817BC8.785F5C44@digeo.com> X-Mailer: Mulberry/2.1.2 (Win32) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1668 Lines: 46 > Sorry, I don't buy that. > > a) It does not need to be architecture neutral. > > b) You surely need a way of communicating the discovered topology > to userspace anyway. > > c) $EDITOR /etc/numa-layouf.conf > > d) $EDITOR /etc/kswapd.conf I guess you could do that, but it seems overly complicated to me. >> I think mbligh recently got the long-needed arch code in >> for cpu to node... But I'm just not able to make the leap of faith that >> memory detection is something that can ever comfortably be given to >> userspace. > > A simple syscall which alows you to launch a kswapd instance against > a group of zones on any group of CPUs provides complete generality > and flexibility to userspace. And it is architecture neutral. > > If it really is incredibly hard to divine the topology from userspace > then you need to fix that up. Provide the topology to userspace. > Which has the added benefit of providing, umm, the topology to userspace ;) Can we make a simple default of 1 per node, which is what 99% of people want, and then make it more complicated later if people complain? It's really pretty easy: for (node = 0; node < numnodes; ++node) { kswapd = kick_off_kswapd_for_node(node); kswapd->cpus_allowed = node_to_cpus(node); } Or whatever the current cpus_allowed method is. All we seem to need is node_to_cpus ... I can give that to you tommorow with no problem, it's trivial. M. - 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/