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 C2AB78E0038 for ; Wed, 9 Jan 2019 05:57:57 -0500 (EST) Received: by mail-ed1-f70.google.com with SMTP id e12so2796329edd.16 for ; Wed, 09 Jan 2019 02:57:57 -0800 (PST) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id l24si1211965edr.135.2019.01.09.02.57.56 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 09 Jan 2019 02:57:56 -0800 (PST) Date: Wed, 9 Jan 2019 11:57:54 +0100 From: Michal Hocko Subject: Re: [PATCH v7] mm/page_alloc.c: memory_hotplug: free pages as higher order Message-ID: <20190109105754.GR31793@dhcp22.suse.cz> References: <1546578076-31716-1-git-send-email-arunks@codeaurora.org> <20190108181352.GI31793@dhcp22.suse.cz> <20190109073718.GM31793@dhcp22.suse.cz> <20190109084031.GN31793@dhcp22.suse.cz> 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: Arun KS Cc: Alexander Duyck , arunks.linux@gmail.com, akpm@linux-foundation.org, vbabka@suse.cz, osalvador@suse.de, linux-kernel@vger.kernel.org, linux-mm@kvack.org, getarunks@gmail.com On Wed 09-01-19 16:12:48, Arun KS wrote: [...] > It will be called once per online of a section and the arg value is always > set to 0 while entering online_pages_range. You rare right that this will be the case in the most simple scenario. But the point is that the callback can be called several times from walk_system_ram_range and then your current code wouldn't work properly. -- Michal Hocko SUSE Labs