From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f70.google.com (mail-ed1-f70.google.com [209.85.208.70]) by kanga.kvack.org (Postfix) with ESMTP id 5AB296B026A for ; Thu, 19 Jul 2018 10:03:12 -0400 (EDT) Received: by mail-ed1-f70.google.com with SMTP id w10-v6so3304065eds.7 for ; Thu, 19 Jul 2018 07:03:12 -0700 (PDT) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id d4-v6si4083668edq.426.2018.07.19.07.03.11 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 19 Jul 2018 07:03:11 -0700 (PDT) Date: Thu, 19 Jul 2018 16:03:08 +0200 From: Michal Hocko Subject: Re: [PATCH v2 5/5] mm/page_alloc: Only call pgdat_set_deferred_range when the system boots Message-ID: <20180719140308.GG7193@dhcp22.suse.cz> References: <20180719132740.32743-1-osalvador@techadventures.net> <20180719132740.32743-6-osalvador@techadventures.net> <20180719134622.GE7193@dhcp22.suse.cz> <20180719135859.GA10988@techadventures.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180719135859.GA10988@techadventures.net> Sender: owner-linux-mm@kvack.org List-ID: To: Oscar Salvador Cc: akpm@linux-foundation.org, pasha.tatashin@oracle.com, vbabka@suse.cz, aaron.lu@intel.com, iamjoonsoo.kim@lge.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Oscar Salvador On Thu 19-07-18 15:58:59, Oscar Salvador wrote: > On Thu, Jul 19, 2018 at 03:46:22PM +0200, Michal Hocko wrote: > > On Thu 19-07-18 15:27:40, osalvador@techadventures.net wrote: > > > From: Oscar Salvador > > > > > > We should only care about deferred initialization when booting. > > > > Again why is this worth doing? > > Well, it is not a big win if that is what you meant. > > Those two fields are only being used when dealing with deferred pages, > which only happens at boot time. > > If later on, free_area_init_node gets called from memhotplug code, > we will also set the fields, although they will not be used. > > Is this a problem? No, but I think it is more clear from the code if we > see when this is called. > So I would say it was only for code consistency. Then put it to the changelog. > If you think this this is not worth, I am ok with dropping it. I am not really sure. I am not a big fan of SYSTEM_BOOTING global thingy so I would rather not spread its usage. -- Michal Hocko SUSE Labs