From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt1-f197.google.com (mail-qt1-f197.google.com [209.85.160.197]) by kanga.kvack.org (Postfix) with ESMTP id 8F09D8E0001 for ; Tue, 22 Jan 2019 18:52:14 -0500 (EST) Received: by mail-qt1-f197.google.com with SMTP id n39so420716qtn.18 for ; Tue, 22 Jan 2019 15:52:14 -0800 (PST) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id v10si1883875qto.109.2019.01.22.15.52.13 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 22 Jan 2019 15:52:13 -0800 (PST) Date: Tue, 22 Jan 2019 18:52:07 -0500 From: Jerome Glisse Subject: Re: [LSF/MM TOPIC] Page flags, can we free up space ? Message-ID: <20190122235207.GC4747@redhat.com> References: <20190122201744.GA3939@redhat.com> <87tvi074gg.fsf@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <87tvi074gg.fsf@linux.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andi Kleen Cc: lsf-pc@lists.linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org On Tue, Jan 22, 2019 at 01:44:15PM -0800, Andi Kleen wrote: > Jerome Glisse writes: > > > > Right now this is more a temptative ie i do not know if i will succeed, > > in any case i can report on failure or success and discuss my finding to > > get people opinions on the matter. > > I would just stop putting node/zone number into the flags. These > could be all handled with a small perfect hash table, like the original > x86_64 port did, which should be quite cheap to look up. > Then there should be enough bits for everyone again. Definitly something i will look into, i was scare to remove those. Cheers, Jérôme