Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261163AbVDYXNV (ORCPT ); Mon, 25 Apr 2005 19:13:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261166AbVDYXNV (ORCPT ); Mon, 25 Apr 2005 19:13:21 -0400 Received: from rrcs-24-227-247-8.sw.biz.rr.com ([24.227.247.8]:22733 "EHLO emachine.austin.ammasso.com") by vger.kernel.org with ESMTP id S261163AbVDYXNS (ORCPT ); Mon, 25 Apr 2005 19:13:18 -0400 Message-ID: <426D797D.3000108@ammasso.com> Date: Mon, 25 Apr 2005 18:13:01 -0500 From: Timur Tabi Organization: Ammasso User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.5) Gecko/20041217 X-Accept-Language: en-us, en, en-gb MIME-Version: 1.0 To: Bob Woodruff CC: "'Andrew Morton'" , "Davis, Arlin R" , hch@infradead.org, linux-kernel@vger.kernel.org, openib-general@openib.org Subject: Re: [openib-general] Re: [PATCH][RFC][0/4] InfiniBand userspace verbsimplementation References: In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1005 Lines: 26 Bob Woodruff wrote: > There definitely needs to be a mechanism to prevent people from pinning > too much memory. Any limit would have to be very high - definitely more than just half. What if the application needs to pin 2GB? The customer is not going to buy 4+ GB of RAM just because Linux doesn't like pinning more than half. In an x86-32 system, that would required PAE support and slow everything down. Off the top of my head, I'd say Linux would need to allow all but 512MB to be pinned. So you have 3GB of RAM, Linux should allow you to pin 2.5GB. -- Timur Tabi Staff Software Engineer timur.tabi@ammasso.com One thing a Southern boy will never say is, "I don't think duct tape will fix it." -- Ed Smylie, NASA engineer for Apollo 13 - 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/