Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757225AbXKATQn (ORCPT ); Thu, 1 Nov 2007 15:16:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754654AbXKATQf (ORCPT ); Thu, 1 Nov 2007 15:16:35 -0400 Received: from mail-gw3.sa.ew.hu ([212.108.200.82]:53441 "EHLO mail-gw3.sa.ew.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754526AbXKATQf (ORCPT ); Thu, 1 Nov 2007 15:16:35 -0400 To: peterz@infradead.org CC: jdike@addtoit.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, hch@infradead.org, akpm@linux-foundation.org, viro@zeniv.linux.org.uk In-reply-to: <1193942132.27652.331.camel@twins> (message from Peter Zijlstra on Thu, 01 Nov 2007 19:35:32 +0100) Subject: Re: per-bdi-throttling: synchronous writepage doesn't work correctly References: <1193935886.27652.313.camel@twins> <1193936949.27652.321.camel@twins> <1193937408.27652.326.camel@twins> <1193942132.27652.331.camel@twins> Message-Id: From: Miklos Szeredi Date: Thu, 01 Nov 2007 20:19:45 +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 794 Lines: 22 > > > > See the file "Locking" for more details. > > > > > > The "should set PG_Writeback" bit threw me off I guess. > > Hmm, set_page_writeback() is also the one clearing the radix tree dirty > tag. So if that is not called, we get in a bit of a mess, no? > > Which makes me think hostfs is buggy. Yes, looks like that sort of usage is not valid. But not clearing the dirty tag won't cause any malfunction, it'll just waste some CPU when looking for dirty pages to write back. This is probably why this wasn't noticed earlier. 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/