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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 3F090C07E96 for ; Thu, 15 Jul 2021 06:00:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 17E2C61358 for ; Thu, 15 Jul 2021 06:00:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233467AbhGOGDI (ORCPT ); Thu, 15 Jul 2021 02:03:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49560 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231910AbhGOGDH (ORCPT ); Thu, 15 Jul 2021 02:03:07 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A27CC06175F for ; Wed, 14 Jul 2021 23:00:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=I0lr9LcilYlAWklp6NCgeJMGcAdgCk8zGjPXcR6M8k8=; b=Ypb40wCuk1pgWMvLizoXk8xXZ5 tUWsGSb74LGl6odYxLBdldq7Y4KTQnD6AqxOzJi++fwPwgXOjEfxaV0tBHVHLWFEaTgzvtdgDyRX+ lkY8cu7F8ZswCMo4njltMNG8XyMgF3NMRyF4CkwXOSYudIDqdcKdltNeEkjdPf77jdkdk4PTAs7vN /9baSpvu1oIyBYP2nWIrlJxBp1UXgqsCsquhf/85q4bQSXeAJIRlREYxe5MGDSGLX4+LZyqFqXIOz TPDex1/+dZ6j+oZu0GsGkTU1IgRTGZSLn5g3vhAAxuCxvdFQeO6KUwR5Xh2DuYYfWWAWdpkToEVxs QMkR0M3g==; Received: from hch by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1m3uP1-0032Wu-7o; Thu, 15 Jul 2021 05:59:35 +0000 Date: Thu, 15 Jul 2021 06:59:19 +0100 From: Christoph Hellwig To: Dave Chinner Cc: Christoph Hellwig , linux-xfs@vger.kernel.org Subject: Re: [PATCH 06/16] xfs: consolidate mount option features in m_features Message-ID: References: <20210714041912.2625692-1-david@fromorbit.com> <20210714041912.2625692-7-david@fromorbit.com> <20210714095507.GZ664593@dread.disaster.area> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210714095507.GZ664593@dread.disaster.area> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Wed, Jul 14, 2021 at 07:55:07PM +1000, Dave Chinner wrote: > > What about using a separate field for these? With this patch we've used > > up all 64-bits in the features field, which isn't exactly the definition > > of future proof.. > > I've used 16 mount option flags and 26 sb feature flags in this > patch set, so there's still 22 feature flags remaining before we > need to split them. This is all in-memory stuff so it's easy to > modify in future. Given that the flag sets are largely set in only > one place each and the check functions are all macro-ised, splitting > them when we do run out of bits is trivial. > > I'm more interested in trying to keep the cache footprint of > frequently accessed read-only data down to a minimum right now, > which is why I aggregated them in the first place... Oh, I missed the hole in the middle. Still not sure if mixing up mount and on-disk flags entirely is something I'm fully comfortable with. What do you think of at least marking the mount options in the name?