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 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 12857ECE560 for ; Fri, 21 Sep 2018 19:41:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BAF8B21550 for ; Fri, 21 Sep 2018 19:41:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BAF8B21550 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=deltatee.com 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 S2391364AbeIVBbl (ORCPT ); Fri, 21 Sep 2018 21:31:41 -0400 Received: from ale.deltatee.com ([207.54.116.67]:45888 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391102AbeIVBbl (ORCPT ); Fri, 21 Sep 2018 21:31:41 -0400 Received: from guinness.priv.deltatee.com ([172.16.1.162]) by ale.deltatee.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.89) (envelope-from ) id 1g3RIi-0002FT-Hh; Fri, 21 Sep 2018 13:41:17 -0600 To: Pasha Tatashin , Alexander Duyck , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "linux-nvdimm@lists.01.org" Cc: "mhocko@suse.com" , "dave.jiang@intel.com" , "mingo@kernel.org" , "dave.hansen@intel.com" , "jglisse@redhat.com" , "akpm@linux-foundation.org" , "dan.j.williams@intel.com" , "kirill.shutemov@linux.intel.com" References: <20180920215824.19464.8884.stgit@localhost.localdomain> <20180920222415.19464.38400.stgit@localhost.localdomain> From: Logan Gunthorpe Message-ID: <4d984974-ff16-35e4-76ff-f5e43e5e90da@deltatee.com> Date: Fri, 21 Sep 2018 13:41:12 -0600 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 172.16.1.162 X-SA-Exim-Rcpt-To: kirill.shutemov@linux.intel.com, dan.j.williams@intel.com, akpm@linux-foundation.org, jglisse@redhat.com, dave.hansen@intel.com, mingo@kernel.org, dave.jiang@intel.com, mhocko@suse.com, linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, alexander.h.duyck@linux.intel.com, Pavel.Tatashin@microsoft.com X-SA-Exim-Mail-From: logang@deltatee.com Subject: Re: [PATCH v4 1/5] mm: Provide kernel parameter to allow disabling page init poisoning X-SA-Exim-Version: 4.2.1 (built Tue, 02 Aug 2016 21:08:31 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018-09-21 1:04 PM, Pasha Tatashin wrote: > >> + pr_err("vm_debug option '%c' unknown. skipped\n", >> + *str); >> + } >> + >> + str++; >> + } >> +out: >> + if (page_init_poisoning && !__page_init_poisoning) >> + pr_warn("Page struct poisoning disabled by kernel command line option 'vm_debug'\n"); > > New lines '\n' can be removed, they are not needed for kprintfs. No, that's not correct. A printk without a newline termination is not emitted as output until the next printk call. (To support KERN_CONT). Therefore removing the '\n' causes a printk to not be printed when it is called which can cause long delayed messages and subtle problems when debugging. Always keep the newline in place even though the kernel will add one for you if it's missing. Logan