From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 1591221A07A80 for ; Wed, 26 Sep 2018 00:38:35 -0700 (PDT) Date: Wed, 26 Sep 2018 09:38:31 +0200 From: Michal Hocko Subject: Re: [PATCH v5 2/4] mm: Provide kernel parameter to allow disabling page init poisoning Message-ID: <20180926073831.GC6278@dhcp22.suse.cz> References: <20180925200551.3576.18755.stgit@localhost.localdomain> <20180925201921.3576.84239.stgit@localhost.localdomain> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20180925201921.3576.84239.stgit@localhost.localdomain> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: Alexander Duyck Cc: pavel.tatashin@microsoft.com, linux-nvdimm@lists.01.org, dave.hansen@intel.com, linux-kernel@vger.kernel.org, mingo@kernel.org, linux-mm@kvack.org, jglisse@redhat.com, rppt@linux.vnet.ibm.com, akpm@linux-foundation.org, kirill.shutemov@linux.intel.com List-ID: On Tue 25-09-18 13:20:12, Alexander Duyck wrote: [...] > + vm_debug[=options] [KNL] Available with CONFIG_DEBUG_VM=y. > + May slow down system boot speed, especially when > + enabled on systems with a large amount of memory. > + All options are enabled by default, and this > + interface is meant to allow for selectively > + enabling or disabling specific virtual memory > + debugging features. > + > + Available options are: > + P Enable page structure init time poisoning > + - Disable all of the above options I agree with Dave that this is confusing as hell. So what does vm_debug (without any options means). I assume it's NOP and all debugging is enabled and that is the default. What if I want to disable _only_ the page struct poisoning. The weird lookcing `-' will disable all other options that we might gather in the future. Why cannot you simply go with [no]vm_page_poison[=on/off]? -- Michal Hocko SUSE Labs _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm 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=-2.5 required=3.0 tests=MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT 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 63EA7C43382 for ; Wed, 26 Sep 2018 07:38:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F402F2089D for ; Wed, 26 Sep 2018 07:38:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F402F2089D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.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 S1727116AbeIZNuK (ORCPT ); Wed, 26 Sep 2018 09:50:10 -0400 Received: from mx2.suse.de ([195.135.220.15]:51202 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726401AbeIZNuK (ORCPT ); Wed, 26 Sep 2018 09:50:10 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 963D6ADDF; Wed, 26 Sep 2018 07:38:33 +0000 (UTC) Date: Wed, 26 Sep 2018 09:38:31 +0200 From: Michal Hocko To: Alexander Duyck Cc: linux-mm@kvack.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, pavel.tatashin@microsoft.com, dave.jiang@intel.com, dave.hansen@intel.com, jglisse@redhat.com, rppt@linux.vnet.ibm.com, dan.j.williams@intel.com, logang@deltatee.com, mingo@kernel.org, kirill.shutemov@linux.intel.com Subject: Re: [PATCH v5 2/4] mm: Provide kernel parameter to allow disabling page init poisoning Message-ID: <20180926073831.GC6278@dhcp22.suse.cz> References: <20180925200551.3576.18755.stgit@localhost.localdomain> <20180925201921.3576.84239.stgit@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180925201921.3576.84239.stgit@localhost.localdomain> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 25-09-18 13:20:12, Alexander Duyck wrote: [...] > + vm_debug[=options] [KNL] Available with CONFIG_DEBUG_VM=y. > + May slow down system boot speed, especially when > + enabled on systems with a large amount of memory. > + All options are enabled by default, and this > + interface is meant to allow for selectively > + enabling or disabling specific virtual memory > + debugging features. > + > + Available options are: > + P Enable page structure init time poisoning > + - Disable all of the above options I agree with Dave that this is confusing as hell. So what does vm_debug (without any options means). I assume it's NOP and all debugging is enabled and that is the default. What if I want to disable _only_ the page struct poisoning. The weird lookcing `-' will disable all other options that we might gather in the future. Why cannot you simply go with [no]vm_page_poison[=on/off]? -- Michal Hocko SUSE Labs