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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 89558C43144 for ; Thu, 28 Jun 2018 01:11:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4C59E25933 for ; Thu, 28 Jun 2018 01:11:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4C59E25933 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932186AbeF1BLn (ORCPT ); Wed, 27 Jun 2018 21:11:43 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:51066 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932090AbeF1BLm (ORCPT ); Wed, 27 Jun 2018 21:11:42 -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 BA82CC74; Thu, 28 Jun 2018 01:11:39 +0000 (UTC) Date: Wed, 27 Jun 2018 18:11:38 -0700 From: Andrew Morton To: Vishwath Mohan Cc: Kostya Serebryany , andreyknvl@google.com, aryabinin@virtuozzo.com, Alexander Potapenko , Dmitry Vyukov , catalin.marinas@arm.com, will.deacon@arm.com, cl@linux.com, mark.rutland@arm.com, Nick Desaulniers , marc.zyngier@arm.com, dave.martin@arm.com, ard.biesheuvel@linaro.org, ebiederm@xmission.com, mingo@kernel.org, Paul Lawrence , geert@linux-m68k.org, arnd@arndb.de, kirill.shutemov@linux.intel.com, gregkh@linuxfoundation.org, kstewart@linuxfoundation.org, rppt@linux.vnet.ibm.com, 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, Evgenii Stepanov , Lee.Smith@arm.com, Ramana.Radhakrishnan@arm.com, Jacob.Bramley@arm.com, Ruben.Ayrapetyan@arm.com, Jann Horn , Mark Brand , cpandya@codeaurora.org Subject: Re: [PATCH v4 00/17] khwasan: kernel hardware assisted address sanitizer Message-Id: <20180627181138.14c9b66e13b8778506205f89@linux-foundation.org> In-Reply-To: References: <20180627160800.3dc7f9ee41c0badbf7342520@linux-foundation.org> 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-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 27 Jun 2018 17:59:00 -0700 Vishwath Mohan wrote: > > > > 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. > > > > On mobile, ASAN's and KASAN's memory usage is a significant problem. > > Not sure if I can find scientific evidence of that. > > CC-ing Vishwath Mohan who deals with KASAN on Android to provide > > anecdotal evidence. > > > Yeah, I can confirm that it's an issue. Like Kostya mentioned, I don't have > data on-hand, but anecdotally both ASAN and KASAN have proven problematic > to enable for environments that don't tolerate the increased memory > pressure well. This includes, > (a) Low-memory form factors - Wear, TV, Things, lower-tier phones like Go > (c) Connected components like Pixel's visual core > > > > These are both places I'd love to have a low(er) memory footprint option at > my disposal. Thanks. It really is important that such information be captured in the changelogs. In as much detail as can be mustered.