From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752579Ab0JPQUX (ORCPT ); Sat, 16 Oct 2010 12:20:23 -0400 Received: from canuck.infradead.org ([134.117.69.58]:59891 "EHLO canuck.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751052Ab0JPQUW (ORCPT ); Sat, 16 Oct 2010 12:20:22 -0400 Date: Sat, 16 Oct 2010 12:20:21 -0400 From: Christoph Hellwig To: Nick Piggin Cc: Christoph Hellwig , Dave Chinner , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 13/18] fs: split locking of inode writeback and LRU lists Message-ID: <20101016162021.GE16861@infradead.org> References: <1286515292-15882-1-git-send-email-david@fromorbit.com> <1286515292-15882-14-git-send-email-david@fromorbit.com> <20101008074243.GB24089@infradead.org> <20101008080018.GV4681@dastard> <20101008081816.GA17577@infradead.org> <20101016075713.GQ19147@amd> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20101016075713.GQ19147@amd> User-Agent: Mutt/1.5.20 (2009-08-17) X-SRS-Rewrite: SMTP reverse-path rewritten from by canuck.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Oct 16, 2010 at 06:57:13PM +1100, Nick Piggin wrote: > > That needs some documentation both in the changelog and in the code > > I think. > > This is another instance where the irregular i_lock locking is making > these little subtleties to the locking. I think that is actually much > worse for maintainence/complexity than a few trylocks which can be > mostly removed with rcu anyway (which are obvious because of the well > documented lock order). Care to explain why? The I_FREEING and co checks are how we do things all over the icache for a long time. They are perfectly easy to understand concept. What I asked Dave about is documenting why he changed things here.