From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm1-f52.google.com (mail-wm1-f52.google.com [209.85.128.52]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 5BE1621A07A80 for ; Fri, 28 Sep 2018 01:44:36 -0700 (PDT) Received: by mail-wm1-f52.google.com with SMTP id o2-v6so1319180wmh.5 for ; Fri, 28 Sep 2018 01:44:36 -0700 (PDT) Date: Fri, 28 Sep 2018 10:44:33 +0200 From: Oscar Salvador Subject: Re: [PATCH v5 4/4] mm: Defer ZONE_DEVICE page initialization to the point where we init pgmap Message-ID: <20180928084433.GB25561@techadventures.net> 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> <20180927110926.GE6278@dhcp22.suse.cz> <20180927122537.GA20378@techadventures.net> <20180927131329.GI6278@dhcp22.suse.cz> <20180928081224.GA25561@techadventures.net> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20180928081224.GA25561@techadventures.net> 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: Michal Hocko 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, kirill.shutemov@linux.intel.com, Alexander Duyck , akpm@linux-foundation.org List-ID: On Fri, Sep 28, 2018 at 10:12:24AM +0200, Oscar Salvador wrote: > Although I am not sure about leaving memmap_init_zone unprotected. > For the normal memory, that is not a problem since the memblock's lock > protects us from touching the same pages at the same time in online/offline_pages, > but for HMM/devm the story is different. > > I am totally unaware of HMM/devm, so I am not sure if its protected somehow. > e.g: what happens if devm_memremap_pages and devm_memremap_pages_release are running > at the same time for the same memory-range (with the assumption that the hotplug-lock > does not protect move_pfn_range_to_zone anymore). I guess that this could not happen since the device is not linked to devm_memremap_pages_release until the end with: devm_add_action(dev, devm_memremap_pages_release, pgmap) -- Oscar Salvador SUSE L3 _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm