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[217.140.101.70]) by mx.google.com with ESMTP id p23si4332199eju.122.2019.04.03.22.25.42 for ; Wed, 03 Apr 2019 22:25:42 -0700 (PDT) Received-SPF: pass (google.com: domain of anshuman.khandual@arm.com designates 217.140.101.70 as permitted sender) client-ip=217.140.101.70; Authentication-Results: mx.google.com; spf=pass (google.com: domain of anshuman.khandual@arm.com designates 217.140.101.70 as permitted sender) smtp.mailfrom=anshuman.khandual@arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 48BD6A78; Wed, 3 Apr 2019 22:25:41 -0700 (PDT) Received: from [10.162.40.100] (p8cg001049571a15.blr.arm.com [10.162.40.100]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1C48C3F721; Wed, 3 Apr 2019 22:25:34 -0700 (PDT) Subject: Re: [PATCH 1/6] arm64/mm: Enable sysfs based memory hot add interface To: David Hildenbrand , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, akpm@linux-foundation.org, will.deacon@arm.com, catalin.marinas@arm.com Cc: mhocko@suse.com, mgorman@techsingularity.net, james.morse@arm.com, mark.rutland@arm.com, robin.murphy@arm.com, cpandya@codeaurora.org, arunks@codeaurora.org, dan.j.williams@intel.com, osalvador@suse.de, logang@deltatee.com, pasha.tatashin@oracle.com, cai@lca.pw References: <1554265806-11501-1-git-send-email-anshuman.khandual@arm.com> <1554265806-11501-2-git-send-email-anshuman.khandual@arm.com> <4b9dd2b0-3b11-608c-1a40-9a3d203dd904@redhat.com> From: Anshuman Khandual Message-ID: Date: Thu, 4 Apr 2019 10:55:36 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <4b9dd2b0-3b11-608c-1a40-9a3d203dd904@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit 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 04/03/2019 01:50 PM, David Hildenbrand wrote: > On 03.04.19 06:30, Anshuman Khandual wrote: >> Sysfs memory probe interface (/sys/devices/system/memory/probe) can accept >> starting physical address of an entire memory block to be hot added into >> the kernel. This is in addition to the existing ACPI based interface. This >> just enables it with the required config CONFIG_ARCH_MEMORY_PROBE. >> > We recently discussed that the similar interface for removal should > rather be moved to a debug/test module. Can we maintain such a debug/test module mainline and enable it when required. Or can have both add and remove interface at /sys/kernel/debug/ just for testing purpose. > > I wonder if we should try to do the same for the sysfs probing > interface. Rather try to get rid of it than open the doors for more users. > I understand your concern. Will drop this patch.