From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 15B85C282C3 for ; Tue, 22 Jan 2019 21:44:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DED94217D6 for ; Tue, 22 Jan 2019 21:44:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726816AbfAVVoQ (ORCPT ); Tue, 22 Jan 2019 16:44:16 -0500 Received: from mga03.intel.com ([134.134.136.65]:48158 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726225AbfAVVoQ (ORCPT ); Tue, 22 Jan 2019 16:44:16 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 22 Jan 2019 13:44:14 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,508,1539673200"; d="scan'208";a="128046630" Received: from tassilo.jf.intel.com (HELO tassilo.localdomain) ([10.7.201.137]) by orsmga002.jf.intel.com with ESMTP; 22 Jan 2019 13:44:15 -0800 Received: by tassilo.localdomain (Postfix, from userid 1000) id B3876301202; Tue, 22 Jan 2019 13:44:15 -0800 (PST) From: Andi Kleen To: Jerome Glisse Cc: lsf-pc@lists.linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [LSF/MM TOPIC] Page flags, can we free up space ? References: <20190122201744.GA3939@redhat.com> Date: Tue, 22 Jan 2019 13:44:15 -0800 In-Reply-To: <20190122201744.GA3939@redhat.com> (Jerome Glisse's message of "Tue, 22 Jan 2019 15:17:44 -0500") Message-ID: <87tvi074gg.fsf@linux.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. -Andi