Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751154AbbEYPYe (ORCPT ); Mon, 25 May 2015 11:24:34 -0400 Received: from cantor2.suse.de ([195.135.220.15]:32768 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750781AbbEYPYb (ORCPT ); Mon, 25 May 2015 11:24:31 -0400 Message-ID: <55633EAC.8060702@suse.cz> Date: Mon, 25 May 2015 17:24:28 +0200 From: Vlastimil Babka User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: Mel Gorman , Michal Hocko CC: Johannes Weiner , Andrew Morton , Naoya Horiguchi , linux-mm@kvack.org, LKML Subject: Re: [PATCH] hugetlb: Do not account hugetlb pages as NR_FILE_PAGES References: <1432214842-22730-1-git-send-email-mhocko@suse.cz> <20150521170909.GA12800@cmpxchg.org> <20150522142143.GF5109@dhcp22.suse.cz> <20150522143558.GA2462@suse.de> In-Reply-To: <20150522143558.GA2462@suse.de> Content-Type: text/plain; charset=iso-8859-15 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1135 Lines: 28 On 05/22/2015 04:35 PM, Mel Gorman wrote: >> >> Thanks! >> >> > This makes a lot of sense to me. The only thing I worry about is the >> > proliferation of PageHuge(), a function call, in relatively hot paths. >> >> I've tried that (see the patch below) but it enlarged the code by almost >> 1k >> text data bss dec hex filename >> 510323 74273 44440 629036 9992c mm/built-in.o.before >> 511248 74273 44440 629961 99cc9 mm/built-in.o.after >> >> I am not sure the code size increase is worth it. Maybe we can reduce >> the check to only PageCompound(page) as huge pages are no in the page >> cache (yet). >> > > That would be a more sensible route because it also avoids exposing the > hugetlbfs destructor unnecessarily. You could maybe do test such as (PageCompound(page) && PageHuge(page)) to short-circuit the call while remaining future-proof. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/