From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756412AbdJJJes (ORCPT ); Tue, 10 Oct 2017 05:34:48 -0400 Received: from mx2.suse.de ([195.135.220.15]:58090 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756265AbdJJJeq (ORCPT ); Tue, 10 Oct 2017 05:34:46 -0400 Subject: Re: [PATCH 1/1] mm: reducing page_owner structure size To: Ayush Mittal , akpm@linux-foundation.org, vinmenon@codeaurora.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: a.sahrawat@samsung.com, pankaj.m@samsung.com, v.narang@samsung.com References: <1507623917-37991-1-git-send-email-ayush.m@samsung.com> From: Vlastimil Babka Message-ID: <31948332-8f98-00c7-4da0-a8d20dacb3ba@suse.cz> Date: Tue, 10 Oct 2017 11:34:44 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: <1507623917-37991-1-git-send-email-ayush.m@samsung.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/10/2017 10:25 AM, Ayush Mittal wrote: > Maximum page order can be at max 10 which can be accomodated > in short data type(2 bytes). > last_migrate_reason is defined as enum type whose values can > be accomodated in short data type (2 bytes). > > Total structure size is currently 16 bytes but after changing structure > size it goes to 12 bytes. > > Signed-off-by: Ayush Mittal Looks like it works, so why not. Before: [ 0.001000] allocated 50331648 bytes of page_ext After: [ 0.001000] allocated 41943040 bytes of page_ext Acked-by: Vlastimil Babka > --- > mm/page_owner.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/mm/page_owner.c b/mm/page_owner.c > index 0fd9dcf..4ab438a 100644 > --- a/mm/page_owner.c > +++ b/mm/page_owner.c > @@ -19,9 +19,9 @@ > #define PAGE_OWNER_STACK_DEPTH (16) > > struct page_owner { > - unsigned int order; > + unsigned short order; > + short last_migrate_reason; > gfp_t gfp_mask; > - int last_migrate_reason; > depot_stack_handle_t handle; > }; > >