Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262620AbVDYOrx (ORCPT ); Mon, 25 Apr 2005 10:47:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262622AbVDYOrx (ORCPT ); Mon, 25 Apr 2005 10:47:53 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:31388 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S262620AbVDYOrw (ORCPT ); Mon, 25 Apr 2005 10:47:52 -0400 Date: Mon, 25 Apr 2005 15:47:49 +0100 From: Christoph Hellwig To: Jes Sorensen Cc: Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: returning non-ram via ->nopage, was Re: [patch] mspec driver for 2.6.12-rc2-mm3 Message-ID: <20050425144749.GA10093@infradead.org> Mail-Followup-To: Christoph Hellwig , Jes Sorensen , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <16987.39773.267117.925489@jaguar.mkp.net> <20050412032747.51c0c514.akpm@osdl.org> <20050413204335.GA17012@infradead.org> <20050424101615.GA22393@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.1i X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1007 Lines: 17 Jes has this shiny new IA64 uncached foo bar whizbang driver (see the patch at http://marc.theaimsgroup.com/?l=linux-kernel&m=111416930927092&w=2), which has a nopage routine that calls remap_pfn_range from ->nopage for uncached memory that's not part of the mem map. Because ->nopage wants to return a struct page * he's allocating a normal kernel page and actually returns that one - to get the page he wants into the pagetables his does all the pagetable manipulation himself before (See the glory details of pagetable walks and modification inside a driver in the patch above). I don't think these hacks are acceptable for a driver, especially as the problem can easily be solved by calling remap_pfn_range in ->mmap - except SGI also wants node locality.. - 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/