From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx181.postini.com [74.125.245.181]) by kanga.kvack.org (Postfix) with SMTP id 86D076B0034 for ; Fri, 26 Jul 2013 17:14:19 -0400 (EDT) Received: from /spool/local by e39.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 26 Jul 2013 15:14:18 -0600 Received: from d01relay04.pok.ibm.com (d01relay04.pok.ibm.com [9.56.227.236]) by d01dlp01.pok.ibm.com (Postfix) with ESMTP id 0917438C8045 for ; Fri, 26 Jul 2013 17:14:14 -0400 (EDT) Received: from d03av03.boulder.ibm.com (d03av03.boulder.ibm.com [9.17.195.169]) by d01relay04.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r6QLEEMS185216 for ; Fri, 26 Jul 2013 17:14:15 -0400 Received: from d03av03.boulder.ibm.com (loopback [127.0.0.1]) by d03av03.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r6QLEEmb006603 for ; Fri, 26 Jul 2013 15:14:14 -0600 From: Cody P Schafer Subject: [PATCH 0/5] Add rbtree postorder iteration functions, runtime tests, and update zswap to use. Date: Fri, 26 Jul 2013 14:13:38 -0700 Message-Id: <1374873223-25557-1-git-send-email-cody@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: LKML , Linux MM , David Woodhouse , Rik van Riel , Michel Lespinasse , Seth Jennings , Cody P Schafer 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 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. 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, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org