Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753534Ab3G2TTo (ORCPT ); Mon, 29 Jul 2013 15:19:44 -0400 Received: from e7.ny.us.ibm.com ([32.97.182.137]:39280 "EHLO e7.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753103Ab3G2TTm (ORCPT ); Mon, 29 Jul 2013 15:19:42 -0400 From: Cody P Schafer To: Andrew Morton Cc: LKML , Linux MM , David Woodhouse , Rik van Riel , Michel Lespinasse , Seth Jennings , Cody P Schafer Subject: [PATCH v2 0/5] Add rbtree postorder iteration functions, runtime tests, and update zswap to use Date: Mon, 29 Jul 2013 12:19:25 -0700 Message-Id: <1375125570-9401-1-git-send-email-cody@linux.vnet.ibm.com> X-Mailer: git-send-email 1.8.3.4 X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13072919-5806-0000-0000-0000223A17D7 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1932 Lines: 49 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 its 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. 1 & 2 add rbtree postorder iteration functions. 3 adds testing of the iteration to the rbtree runtime tests 4 allows building the rbtree runtime tests as builtins 5 updates zswap. -- since v1: - spacing - s/it's/its/ - remove now unused var in zswap code. - 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 | 22 ++++++++++++++++++++++ lib/Kconfig.debug | 2 +- lib/rbtree.c | 40 ++++++++++++++++++++++++++++++++++++++++ lib/rbtree_test.c | 12 ++++++++++++ mm/zswap.c | 16 ++-------------- 5 files changed, 77 insertions(+), 15 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/