From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f71.google.com (mail-ed1-f71.google.com [209.85.208.71]) by kanga.kvack.org (Postfix) with ESMTP id 71C578E0001 for ; Thu, 27 Sep 2018 07:20:43 -0400 (EDT) Received: by mail-ed1-f71.google.com with SMTP id w44-v6so2918253edb.16 for ; Thu, 27 Sep 2018 04:20:43 -0700 (PDT) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id l4si585406edw.439.2018.09.27.04.20.42 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 27 Sep 2018 04:20:42 -0700 (PDT) Date: Thu, 27 Sep 2018 13:20:41 +0200 From: Michal Hocko Subject: Re: [PATCH v5 4/4] mm: Defer ZONE_DEVICE page initialization to the point where we init pgmap Message-ID: <20180927112041.GG6278@dhcp22.suse.cz> References: <20180925200551.3576.18755.stgit@localhost.localdomain> <20180925202053.3576.66039.stgit@localhost.localdomain> <20180926075540.GD6278@dhcp22.suse.cz> <6f87a5d7-05e2-00f4-8568-bb3521869cea@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Dan Williams Cc: alexander.h.duyck@linux.intel.com, Linux MM , Andrew Morton , Linux Kernel Mailing List , linux-nvdimm , Pasha Tatashin , Dave Jiang , Dave Hansen , =?iso-8859-1?B?Suly9G1l?= Glisse , rppt@linux.vnet.ibm.com, Logan Gunthorpe , Ingo Molnar , "Kirill A. Shutemov" On Wed 26-09-18 11:52:56, Dan Williams wrote: [...] > Could we push the hotplug lock deeper to the places that actually need > it? What I found with my initial investigation is that we don't even > need the hotplug lock for the vmemmap initialization with this patch > [1]. Yes, the scope of the hotplug lock should be evaluated and _documented_. Then we can build on top. -- Michal Hocko SUSE Labs