From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965187AbXCFV1M (ORCPT ); Tue, 6 Mar 2007 16:27:12 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965185AbXCFV1M (ORCPT ); Tue, 6 Mar 2007 16:27:12 -0500 Received: from mail-gw3.sa.ew.hu ([212.108.200.82]:47609 "EHLO mail-gw3.sa.ew.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965164AbXCFV1K (ORCPT ); Tue, 6 Mar 2007 16:27:10 -0500 To: a.p.zijlstra@chello.nl CC: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, staubach@redhat.com, hugh@veritas.com In-reply-to: <1173213151.4718.16.camel@lappy> (message from Peter Zijlstra on Tue, 06 Mar 2007 21:32:31 +0100) Subject: Re: [patch 2/8] update ctime and mtime for mmaped write References: <20070306180443.669036741@szeredi.hu> <20070306180549.312408559@szeredi.hu> <1173213151.4718.16.camel@lappy> Message-Id: From: Miklos Szeredi Date: Tue, 06 Mar 2007 22:24:17 +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > I'm not liking this, its not a constant operation as the name implies. OK, I'll think of something better. > And it style is a bit out of line with the rest of rmap. > > The thing it actually does is page_mkclean(), all it doesn't do is > setting the pte read-only. > > I can understand you wanting to avoid the overhead of the minor faults > resulting from using page_mkclean(), but I'm not sure its worth it. It would be nice if the cost of MS_ASYNC wouldn't be too high. And I do have the feeling that minor faults are far more expensive than cleaning the dirty bit in the ptes. Do you have any numbers? Thanks, Miklos