From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 1DA307D072 for ; Wed, 27 Jun 2018 23:08:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752113AbeF0XIF (ORCPT ); Wed, 27 Jun 2018 19:08:05 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:41684 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751854AbeF0XIE (ORCPT ); Wed, 27 Jun 2018 19:08:04 -0400 Received: from localhost.localdomain (c-24-4-125-7.hsd1.ca.comcast.net [24.4.125.7]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 4B74A9F0; Wed, 27 Jun 2018 23:08:02 +0000 (UTC) Date: Wed, 27 Jun 2018 16:08:00 -0700 From: Andrew Morton To: Andrey Konovalov Cc: Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , Catalin Marinas , Will Deacon , Christoph Lameter , Mark Rutland , Nick Desaulniers , Marc Zyngier , Dave Martin , Ard Biesheuvel , "Eric W . Biederman" , Ingo Molnar , Paul Lawrence , Geert Uytterhoeven , Arnd Bergmann , "Kirill A . Shutemov" , Greg Kroah-Hartman , Kate Stewart , Mike Rapoport , kasan-dev@googlegroups.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sparse@vger.kernel.org, linux-mm@kvack.org, linux-kbuild@vger.kernel.org, Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Jann Horn , Mark Brand , Chintan Pandya Subject: Re: [PATCH v4 00/17] khwasan: kernel hardware assisted address sanitizer Message-Id: <20180627160800.3dc7f9ee41c0badbf7342520@linux-foundation.org> In-Reply-To: References: X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Tue, 26 Jun 2018 15:15:10 +0200 Andrey Konovalov wrote: > This patchset adds a new mode to KASAN [1], which is called KHWASAN > (Kernel HardWare assisted Address SANitizer). > > The plan is to implement HWASan [2] for the kernel with the incentive, > that it's going to have comparable to KASAN performance, but in the same > time consume much less memory, trading that off for somewhat imprecise > bug detection and being supported only for arm64. Why do we consider this to be a worthwhile change? Is KASAN's memory consumption actually a significant problem? Some data regarding that would be very useful. If it is a large problem then we still have that problem on x86, so the problem remains largely unsolved? > ====== Benchmarks > > The following numbers were collected on Odroid C2 board. Both KASAN and > KHWASAN were used in inline instrumentation mode. > > Boot time [1]: > * ~1.7 sec for clean kernel > * ~5.0 sec for KASAN > * ~5.0 sec for KHWASAN > > Slab memory usage after boot [2]: > * ~40 kb for clean kernel > * ~105 kb + 1/8th shadow ~= 118 kb for KASAN > * ~47 kb + 1/16th shadow ~= 50 kb for KHWASAN > > Network performance [3]: > * 8.33 Gbits/sec for clean kernel > * 3.17 Gbits/sec for KASAN > * 2.85 Gbits/sec for KHWASAN > > Note, that KHWASAN (compared to KASAN) doesn't require quarantine. > > [1] Time before the ext4 driver is initialized. > [2] Measured as `cat /proc/meminfo | grep Slab`. > [3] Measured as `iperf -s & iperf -c 127.0.0.1 -t 30`. The above doesn't actually demonstrate the whole point of the patchset: to reduce KASAN's very high memory consumption? -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html