Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756484Ab3G3PYU (ORCPT ); Tue, 30 Jul 2013 11:24:20 -0400 Received: from e28smtp07.in.ibm.com ([122.248.162.7]:59611 "EHLO e28smtp07.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754420Ab3G3PXs (ORCPT ); Tue, 30 Jul 2013 11:23:48 -0400 Date: Mon, 29 Jul 2013 10:11:04 -0500 From: Seth Jennings To: Cody P Schafer Cc: Andrew Morton , LKML , Linux MM , David Woodhouse , Rik van Riel , Michel Lespinasse Subject: Re: [PATCH 0/5] Add rbtree postorder iteration functions, runtime tests, and update zswap to use. Message-ID: <20130729151104.GD4381@variantweb.net> References: <1374873223-25557-1-git-send-email-cody@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1374873223-25557-1-git-send-email-cody@linux.vnet.ibm.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13073015-8878-0000-0000-0000082C3292 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1900 Lines: 47 On Fri, Jul 26, 2013 at 02:13:38PM -0700, Cody P Schafer wrote: > Postorder iteration yields all of a node's children prior to yielding the node > itself, and this particular implementation also avoids examining the leaf links > in a node after that node has been yielded. > > In what I expect will be it's most common usage, postorder iteration allows the s/it's/its/ > deletion of every node in an rbtree without modifying the rbtree nodes (no > _requirement_ that they be nulled) while avoiding referencing child nodes after > they have been "deleted" (most commonly, freed). > > I have only updated zswap to use this functionality at this point, but numerous > bits of code (most notably in the filesystem drivers) use a hand rolled > postorder iteration that NULLs child links as it traverses the tree. Each of > those instances could be replaced with this common implementation. Thanks for doing this Cody! Other than the nits I've sent, it looks good. Whole set: Reviewed-by: Seth Jennings > > Cody P Schafer (5): > rbtree: add postorder iteration functions. > rbtree: add rbtree_postorder_for_each_entry_safe() helper. > rbtree_test: add test for postorder iteration. > rbtree: allow tests to run as builtin > mm/zswap: use postorder iteration when destroying rbtree > > include/linux/rbtree.h | 21 +++++++++++++++++++++ > lib/Kconfig.debug | 2 +- > lib/rbtree.c | 40 ++++++++++++++++++++++++++++++++++++++++ > lib/rbtree_test.c | 12 ++++++++++++ > mm/zswap.c | 15 ++------------- > 5 files changed, 76 insertions(+), 14 deletions(-) > > -- > 1.8.3.4 > -- 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/