From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261652AbUKITv6 (ORCPT ); Tue, 9 Nov 2004 14:51:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261649AbUKITv5 (ORCPT ); Tue, 9 Nov 2004 14:51:57 -0500 Received: from fw.osdl.org ([65.172.181.6]:52120 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S261652AbUKITvd (ORCPT ); Tue, 9 Nov 2004 14:51:33 -0500 Date: Tue, 9 Nov 2004 11:51:22 -0800 From: Andrew Morton To: Andrea Arcangeli Cc: shaggy@austin.ibm.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH] zap_pte_range should not mark non-uptodate pages dirty Message-Id: <20041109115122.767f923f.akpm@osdl.org> In-Reply-To: <20041109144659.GC17639@x30.random> References: <20041021223613.GA8756@dualathlon.random> <20041021160233.68a84971.akpm@osdl.org> <20041021232059.GE8756@dualathlon.random> <20041021164245.4abec5d2.akpm@osdl.org> <20041022003004.GA14325@dualathlon.random> <20041022012211.GD14325@dualathlon.random> <20041021190320.02dccda7.akpm@osdl.org> <20041022161744.GF14325@dualathlon.random> <20041022162433.509341e4.akpm@osdl.org> <1100009730.7478.1.camel@localhost> <20041109144659.GC17639@x30.random> X-Mailer: Sylpheed version 0.9.7 (GTK+ 1.2.10; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andrea Arcangeli wrote: > > On Tue, Nov 09, 2004 at 08:15:30AM -0600, Dave Kleikamp wrote: > > Andrew & Andrea, > > What is the status of this patch? It would be nice to have it in the > > -mm4 kernel. > > I think we should add an msync in front of O_DIRECT reads too (msync > won't hurt other users, and it'll provide full coherency), everything > else is ok (the msync can be added as an incremental patch). I don't think we have a simple way of syncing all ptes which map the pages without actually shooting those pte's down, via zap_page_range(). A filemap_sync() will only sync the caller's mm's ptes. I guess it would be pretty simple to add a sync_but_dont_unmap field to struct zap_details, and propagate that down. So we can reuse all the unmap_vmas() code for an all-mms pte sync. It could all get very expensive if someone has a bit of the file mapped though. Testing is needed there. From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 9 Nov 2004 11:51:22 -0800 From: Andrew Morton Subject: Re: [PATCH] zap_pte_range should not mark non-uptodate pages dirty Message-Id: <20041109115122.767f923f.akpm@osdl.org> In-Reply-To: <20041109144659.GC17639@x30.random> References: <20041021223613.GA8756@dualathlon.random> <20041021160233.68a84971.akpm@osdl.org> <20041021232059.GE8756@dualathlon.random> <20041021164245.4abec5d2.akpm@osdl.org> <20041022003004.GA14325@dualathlon.random> <20041022012211.GD14325@dualathlon.random> <20041021190320.02dccda7.akpm@osdl.org> <20041022161744.GF14325@dualathlon.random> <20041022162433.509341e4.akpm@osdl.org> <1100009730.7478.1.camel@localhost> <20041109144659.GC17639@x30.random> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Andrea Arcangeli Cc: shaggy@austin.ibm.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: Andrea Arcangeli wrote: > > On Tue, Nov 09, 2004 at 08:15:30AM -0600, Dave Kleikamp wrote: > > Andrew & Andrea, > > What is the status of this patch? It would be nice to have it in the > > -mm4 kernel. > > I think we should add an msync in front of O_DIRECT reads too (msync > won't hurt other users, and it'll provide full coherency), everything > else is ok (the msync can be added as an incremental patch). I don't think we have a simple way of syncing all ptes which map the pages without actually shooting those pte's down, via zap_page_range(). A filemap_sync() will only sync the caller's mm's ptes. I guess it would be pretty simple to add a sync_but_dont_unmap field to struct zap_details, and propagate that down. So we can reuse all the unmap_vmas() code for an all-mms pte sync. It could all get very expensive if someone has a bit of the file mapped though. Testing is needed there. -- 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