From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B82BFC433E1 for ; Tue, 25 Aug 2020 14:52:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7FDC22075F for ; Tue, 25 Aug 2020 14:52:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726737AbgHYOwl convert rfc822-to-8bit (ORCPT ); Tue, 25 Aug 2020 10:52:41 -0400 Received: from eu-smtp-delivery-151.mimecast.com ([185.58.86.151]:23646 "EHLO eu-smtp-delivery-151.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726230AbgHYOwj (ORCPT ); Tue, 25 Aug 2020 10:52:39 -0400 Received: from AcuMS.aculab.com (156.67.243.126 [156.67.243.126]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mta-163-BWui7J3WNwSfPV_ZLU2-Dg-1; Tue, 25 Aug 2020 15:52:35 +0100 X-MC-Unique: BWui7J3WNwSfPV_ZLU2-Dg-1 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) by AcuMS.aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Tue, 25 Aug 2020 15:52:34 +0100 Received: from AcuMS.Aculab.com ([fe80::43c:695e:880f:8750]) by AcuMS.aculab.com ([fe80::43c:695e:880f:8750%12]) with mapi id 15.00.1347.000; Tue, 25 Aug 2020 15:52:34 +0100 From: David Laight To: "linux-kernel@vger.kernel.org" , "'linux-sctp@vger.kernel.org'" , Eric Biggers , 'Marcelo Ricardo Leitner' , 'Catalin Marinas' , "'kent.overstreet@gmail.com'" , Andrew Morton , "'Neil Horman'" Subject: [PATCH 00/13] lib/generic-radix-tree: genradix bug fix and optimisations. Thread-Topic: [PATCH 00/13] lib/generic-radix-tree: genradix bug fix and optimisations. Thread-Index: AdZ67b0yl7qlbV/xQHyOe3+CAeHrEg== Date: Tue, 25 Aug 2020 14:52:34 +0000 Message-ID: <21289d79b0474811b21ed8478c465159@AcuMS.aculab.com> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=C51A453 smtp.mailfrom=david.laight@aculab.com X-Mimecast-Spam-Score: 0.002 X-Mimecast-Originator: aculab.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The genradix code is used by SCTP for accessing per-stream data. This means there are quite a lot of lookups but the code wasn't really optimised at all. Patch 1 fixes a rather nasty bug that could cause all sorts of oddities including having a loop in a tree. Fortunately the only 2 users of the genradix code in the kernel source tree and neither can possibly hit the bug. Patches 2 through 11 all reduce codepath. Especially for the common case (for both users) where all the data fits in one page. Patch 12 inlines the common lookup function for 1 page trees. This also remove the '% constant' calcuation from the lookups. However it will increase code size (but not codepath) because of the number of callers. Patch 13 removes part of the optimisation for 1 page tress under the assumption that the lookup will have been inlined. The code still works even if inlining didn't happen. David Laight (13): 01/13: Fix potentially corrupt tree 02/13: Optimise out ilog2(variable). 03/13: Always use low 8 bits of 'root' for depth. 04/13: Optimise __genradix_ptr() 05/13: Optimise __genradix_ptr_alloc() 06/13: Rename gfp_mask to gfp to shorten lines. 07/13: Optimise __genradix_iter_peek() 08/13: Save number of bits to shift instead of tree level. 09/13: Check sizeof(_type) when defining a tree. 10/13: Simplify offset calculation: 11/13: Pass the root pointer to __genradix_ptr. 12/13: Inline genradix_ptr() for simple trees. 13/13: Simplify __genradix_ptr() include/linux/generic-radix-tree.h | 54 ++++--- lib/generic-radix-tree.c | 224 ++++++++++++++++------------- 2 files changed, 162 insertions(+), 116 deletions(-) -- 2.25.1 - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)