From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f173.google.com (mail-wi0-f173.google.com [209.85.212.173]) by kanga.kvack.org (Postfix) with ESMTP id CFC596B0038 for ; Thu, 10 Sep 2015 05:42:00 -0400 (EDT) Received: by wiclk2 with SMTP id lk2so16044289wic.1 for ; Thu, 10 Sep 2015 02:42:00 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id k10si18448703wje.157.2015.09.10.02.41.59 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 10 Sep 2015 02:41:59 -0700 (PDT) Subject: Re: [PATCHv5 4/7] mm: pack compound_dtor and compound_order into one word in struct page References: <1441283758-92774-1-git-send-email-kirill.shutemov@linux.intel.com> <1441283758-92774-5-git-send-email-kirill.shutemov@linux.intel.com> From: Vlastimil Babka Message-ID: <55F15064.9040507@suse.cz> Date: Thu, 10 Sep 2015 11:41:56 +0200 MIME-Version: 1.0 In-Reply-To: <1441283758-92774-5-git-send-email-kirill.shutemov@linux.intel.com> Content-Type: text/plain; charset=iso-8859-2 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: "Kirill A. Shutemov" , Andrew Morton , Hugh Dickins Cc: Andrea Arcangeli , Dave Hansen , Johannes Weiner , Michal Hocko , David Rientjes , "Aneesh Kumar K.V" , linux-kernel@vger.kernel.org, linux-mm@kvack.org On 09/03/2015 02:35 PM, Kirill A. Shutemov wrote: > The patch halves space occupied by compound_dtor and compound_order in > struct page. > > For compound_order, it's trivial long -> short conversion. > > For get_compound_page_dtor(), we now use hardcoded table for destructor > lookup and store its index in the struct page instead of direct pointer > to destructor. It shouldn't be a big trouble to maintain the table: we > have only two destructor and NULL currently. > > This patch free up one word in tail pages for reuse. This is preparation > for the next patch. > > Signed-off-by: Kirill A. Shutemov > Reviewed-by: Michal Hocko Acked-by: Vlastimil Babka -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org