Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753711AbXKAQqI (ORCPT ); Thu, 1 Nov 2007 12:46:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752229AbXKAQp5 (ORCPT ); Thu, 1 Nov 2007 12:45:57 -0400 Received: from mail-gw2.sa.eol.hu ([212.108.200.109]:33721 "EHLO mail-gw2.sa.eol.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750785AbXKAQp4 (ORCPT ); Thu, 1 Nov 2007 12:45:56 -0400 To: a.p.zijlstra@chello.nl CC: jdike@addtoit.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: per-bdi-throttling: synchronous writepage doesn't work correctly Message-Id: From: Miklos Szeredi Date: Thu, 01 Nov 2007 17:49:54 +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 659 Lines: 18 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... 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/