From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from westrelay02.boulder.ibm.com (westrelay02.boulder.ibm.com [9.17.195.11]) by e32.co.us.ibm.com (8.12.10/8.12.9) with ESMTP id j4J0RQ0c162378 for ; Wed, 18 May 2005 20:27:26 -0400 Received: from d03av01.boulder.ibm.com (d03av01.boulder.ibm.com [9.17.195.167]) by westrelay02.boulder.ibm.com (8.12.10/NCO/VER6.6) with ESMTP id j4J0RP1o184650 for ; Wed, 18 May 2005 18:27:25 -0600 Received: from d03av01.boulder.ibm.com (loopback [127.0.0.1]) by d03av01.boulder.ibm.com (8.12.11/8.13.3) with ESMTP id j4J0RPjj013089 for ; Wed, 18 May 2005 18:27:25 -0600 Subject: Re: page flags ? From: Badari Pulavarty In-Reply-To: <20050518162302.13a13356.akpm@osdl.org> References: <1116450834.26913.1293.camel@dyn318077bld.beaverton.ibm.com> <20050518145644.717afc21.akpm@osdl.org> <1116456143.26913.1303.camel@dyn318077bld.beaverton.ibm.com> <20050518162302.13a13356.akpm@osdl.org> Content-Type: text/plain Message-Id: <1116461369.26913.1339.camel@dyn318077bld.beaverton.ibm.com> Mime-Version: 1.0 Date: 18 May 2005 17:09:29 -0700 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: linux-mm@kvack.org, linux-fsdevel List-ID: On Wed, 2005-05-18 at 16:23, Andrew Morton wrote: > Badari Pulavarty wrote: > > > > Is it possible to get yet another PG_fs_specific flag ? > > Anything's possible ;) > > How many bits are spare now? ZONETABLE_PGSHIFT hurts my brain. Depends on whom you ask :) CKRM folks are using one/few, Hotplug memory guys are using one... :( I lost track.. > > > Reasons for it are: > > > > - I need this for supporting delayed allocation on ext3. > > Why? > I think, I explained you earlier.. But let me refresh your memory. In order to do delayed allocation, we "reserve" (not same reservation the code) a block in prepare/commit and do the allocation in writepage/writepages. Unfortunately, mapped writes directly come into writepage without making a reservation. In order to guarantee that write() succeeds, I need a way to indicate if the "page" has made a reservation or not. I was hoping to use a page->flag to do this. That way I don't have to touch page->private like Alex's code and get away using mpage routines, instead of having my own. Thanks, Badari -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: aart@kvack.org