Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261324AbVEDS0B (ORCPT ); Wed, 4 May 2005 14:26:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261246AbVEDSYy (ORCPT ); Wed, 4 May 2005 14:24:54 -0400 Received: from zproxy.gmail.com ([64.233.162.197]:20883 "EHLO zproxy.gmail.com") by vger.kernel.org with ESMTP id S261324AbVEDSWF convert rfc822-to-8bit (ORCPT ); Wed, 4 May 2005 14:22:05 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:reply-to:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=MQ9RbIvL52SquiX6E4iskSAKGRVIrc/Wluua0eE++j3dNxux3BOkfILWFgjb8N30W3bLRTgJwSxUYB+ktATP8+xKfvuzlJgzqBA5a7pJpdrDcFHVDCo0xtOFTF6P5rSydApDCa9trrRDFQQcM0p/cw5tN95nKpF2ghpOozAKtSY= Message-ID: <78d18e2050504112240e43a08@mail.gmail.com> Date: Wed, 4 May 2005 14:22:00 -0400 From: William Jordan Reply-To: William Jordan To: Andy Isaacson Subject: Re: [openib-general] Re: [PATCH][RFC][0/4] InfiniBand userspace verbs implementation Cc: Caitlin Bestler , Andrew Morton , linux-kernel@vger.kernel.org, openib-general@openib.org, hch@infradead.org, Timur Tabi In-Reply-To: <20050503184325.GA19351@hexapodia.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Content-Disposition: inline References: <469958e00504291731eb8287c@mail.gmail.com> <20050503184325.GA19351@hexapodia.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 810 Lines: 21 On 5/3/05, Andy Isaacson wrote: > Rather than replacing the fully-registered pages with pages of zeros, > you could simply unmap them. I don't like this option. It is nearly free to map all of the pages to the zero-page. You never have to allocate a page if the user never writes to it. Buf if you unmap the page, there could be issues. The memory region could be on the stack, or malloc'ed. In these cases, the child should be able to return from the function, or free the memory without setting a timebomb. -- Bill Jordan InfiniCon Systems - 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/