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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 E654FC2BA19 for ; Thu, 9 Apr 2020 20:55:55 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 80E8520730 for ; Thu, 9 Apr 2020 20:55:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="kzKGGLqr" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 80E8520730 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=nvidia.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id D91678E0016; Thu, 9 Apr 2020 16:55:54 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D41978E0003; Thu, 9 Apr 2020 16:55:54 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C57A78E0016; Thu, 9 Apr 2020 16:55:54 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0083.hostedemail.com [216.40.44.83]) by kanga.kvack.org (Postfix) with ESMTP id B8CFE8E0003 for ; Thu, 9 Apr 2020 16:55:54 -0400 (EDT) Received: from smtpin30.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 8F20298A9 for ; Thu, 9 Apr 2020 20:55:54 +0000 (UTC) X-FDA: 76689523428.30.death02_6dbec2434bd13 X-HE-Tag: death02_6dbec2434bd13 X-Filterd-Recvd-Size: 4253 Received: from hqnvemgate26.nvidia.com (hqnvemgate26.nvidia.com [216.228.121.65]) by imf13.hostedemail.com (Postfix) with ESMTP for ; Thu, 9 Apr 2020 20:55:53 +0000 (UTC) Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate26.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Thu, 09 Apr 2020 13:55:40 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Thu, 09 Apr 2020 13:55:52 -0700 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Thu, 09 Apr 2020 13:55:52 -0700 Received: from DRHQMAIL107.nvidia.com (10.27.9.16) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Thu, 9 Apr 2020 20:55:52 +0000 Received: from [10.2.58.92] (10.124.1.5) by DRHQMAIL107.nvidia.com (10.27.9.16) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Thu, 9 Apr 2020 20:55:51 +0000 Subject: Re: [PATCH 0/5] Improve page poisoning implementation To: Pavel Tatashin , Matthew Wilcox CC: linux-mm , "Kirill A. Shutemov" References: <20200408150148.25290-1-willy@infradead.org> From: John Hubbard X-Nvconfidentiality: public Message-ID: <8cd78caa-9698-fbcc-9cce-4d9c603f9702@nvidia.com> Date: Thu, 9 Apr 2020 13:55:51 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: X-Originating-IP: [10.124.1.5] X-ClientProxiedBy: HQMAIL111.nvidia.com (172.20.187.18) To DRHQMAIL107.nvidia.com (10.27.9.16) Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1586465740; bh=Ot8N42xaFY5YljVaF/60JAdRtqY8l9cIL1uAYHDzXg8=; h=X-PGP-Universal:Subject:To:CC:References:From:X-Nvconfidentiality: Message-ID:Date:User-Agent:MIME-Version:In-Reply-To: X-Originating-IP:X-ClientProxiedBy:Content-Type:Content-Language: Content-Transfer-Encoding; b=kzKGGLqr3caMnzeL0JF4lj8N1J6Z20yOHWFfyrVtDq0leMe2SOI01JkcQmT7Qff/A xVQ2HXG4NW3HbkcEQsqy8A4AUyFzbBsLFLoQPHFGC8YUNNW/GvjunhkcC0+pbNBI93 1iR0xPcf976S+E8sfv+sPYF8Zd21KJlrLnhldUrOaKUm422CedSUpEyzqmzqS+Xqk/ 59tHSCe5PW07i+q/idS+7FzxKgCi93NPw2zeUFDJOE/lupxKXS/d6RkUnKVf74gXoQ 3QEoLnwXi6Ro+8XSBuH4uvy51W5loS0tNL4dc1pp4s6MI748OR5BF5hxNQS1SNOi63 X/XvDzzCONRnw== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 4/8/20 8:11 AM, Pavel Tatashin wrote: > On Wed, Apr 8, 2020 at 11:01 AM Matthew Wilcox wrote: >> >> From: "Matthew Wilcox (Oracle)" >> >> I really don't like that this feature is called page poisoning. >> We already had something called page poisoning and it's when you detect >> a memory error in a page. This is just uninitialised pages. I don't > > Hi Matthew, > > Thank you for working on this. Uninitialized struct pages are often > zeroed by firmware, and there were a number of implicit assumptions > about that memory when I worked on deferred page initializations, this > is why it is important to also test when struct pages are specifically > set to a pattern that is not all zeroes, something that can happen > during kexec, or when memory allocated and freed by kernel during > boot. We have caught a good number of bugs using this mechanism. So, > this is poisoning, but I agree "page poisoning" name is misleading, as > we have this term used in another place. So, lets agree on a better > term: how about memmap poisoning (s/page_poisoning/memmap_poisoning/)? > Better to avoid the "poison" word entirely. It's just too well-established as a hardware memory error case. Early ideas for other names, just to get started: use "uninitialize" or "deinitialize" instead of "poison". So approximately: page_deinit page_deinitialize page_uninit page_uninitialize mem_deinit ...other variations... thanks, -- John Hubbard NVIDIA