Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756882AbXKAQ4w (ORCPT ); Thu, 1 Nov 2007 12:56:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753005AbXKAQ4n (ORCPT ); Thu, 1 Nov 2007 12:56:43 -0400 Received: from mail-gw2.sa.eol.hu ([212.108.200.109]:35280 "EHLO mail-gw2.sa.eol.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753056AbXKAQ4m (ORCPT ); Thu, 1 Nov 2007 12:56:42 -0400 To: a.p.zijlstra@chello.nl CC: jdike@addtoit.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org In-reply-to: <1193935886.27652.313.camel@twins> (message from Peter Zijlstra on Thu, 01 Nov 2007 17:51:26 +0100) Subject: Re: per-bdi-throttling: synchronous writepage doesn't work correctly References: <1193935886.27652.313.camel@twins> Message-Id: From: Miklos Szeredi Date: Thu, 01 Nov 2007 18:00:47 +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 919 Lines: 25 > > Hi, > > > > It looks like bdi_thresh will always be zero if filesystem does > > synchronous writepage, resulting in very poor write performance. > > > > Hostfs (UML) is one such example, but there might be others. > > > > The only solution I can think of is to add a set_page_writeback(); > > end_page_writeback() pair (or some reduced variant, that only does > > the proportions magic). But that means auditing quite a few > > filesystems... > > Ouch... > > I take it there is no other function that is shared between all these > writeout paths which we could stick a bdi_writeout_inc(bdi) in? No, and you can't detect it from the callers either I think. Miklos - 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/