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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 B3010C6379D for ; Mon, 16 Nov 2020 18:49:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 717232224B for ; Mon, 16 Nov 2020 18:49:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728226AbgKPStW (ORCPT ); Mon, 16 Nov 2020 13:49:22 -0500 Received: from mga02.intel.com ([134.134.136.20]:50413 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727701AbgKPStV (ORCPT ); Mon, 16 Nov 2020 13:49:21 -0500 IronPort-SDR: isxPLhZX6e4/B74nh8z4uG3vOKzpEKkpbZyptzktclqw6xWlfNfccQ56UOcem5Mvd4UkjTQlnY R31xfgo1knuw== X-IronPort-AV: E=McAfee;i="6000,8403,9807"; a="157821919" X-IronPort-AV: E=Sophos;i="5.77,483,1596524400"; d="scan'208";a="157821919" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Nov 2020 10:49:18 -0800 IronPort-SDR: QM3K1Df9J/Wg+oJAcVfa83qY/TNr4BOrYcj8zI8YrrZ97jsEsonZ8J/uK1N6DUXothgxIsiUVW Pzs792lhR6LA== X-IronPort-AV: E=Sophos;i="5.77,483,1596524400"; d="scan'208";a="533514829" Received: from iweiny-desk2.sc.intel.com (HELO localhost) ([10.3.52.147]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Nov 2020 10:49:17 -0800 Date: Mon, 16 Nov 2020 10:49:16 -0800 From: Ira Weiny To: Thomas Gleixner Cc: Ingo Molnar , Borislav Petkov , Andy Lutomirski , Peter Zijlstra , Dave Hansen , x86@kernel.org, linux-kernel@vger.kernel.org, Andrew Morton , Fenghua Yu , linux-doc@vger.kernel.org, linux-nvdimm@lists.01.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, Dan Williams , Greg KH Subject: Re: [PATCH V3 05/10] x86/entry: Pass irqentry_state_t by reference Message-ID: <20201116184916.GA722447@iweiny-DESK2.sc.intel.com> References: <20201106232908.364581-1-ira.weiny@intel.com> <20201106232908.364581-6-ira.weiny@intel.com> <87mtzi8n0z.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87mtzi8n0z.fsf@nanos.tec.linutronix.de> User-Agent: Mutt/1.11.1 (2018-12-01) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Nov 15, 2020 at 07:58:52PM +0100, Thomas Gleixner wrote: > Ira, > > On Fri, Nov 06 2020 at 15:29, ira weiny wrote: > > Subject prefix wants to 'entry:'. This changes generic code and the x86 > part is just required to fix the generic code change. Sorry, yes that was carried incorrectly from earlier versions. > > > Currently struct irqentry_state_t only contains a single bool value > > which makes passing it by value is reasonable. However, future patches > > propose to add information to this struct, for example the PKRS > > register/thread state. > > > > Adding information to irqentry_state_t makes passing by value less > > efficient. Therefore, change the entry/exit calls to pass irq_state by > > reference. > > The PKRS muck needs to add an u32 to that struct. So how is that a > problem? There are more fields to be added for the kmap/pmem support. So this will be needed eventually. Even though it is not strictly necessary in the next patch. > > The resulting struct still fits into 64bit which is by far more > efficiently passed by value than by reference. So which problem are you > solving here? I'm getting ahead of myself a bit. I will be adding more fields for the kmap/pmem tracking. Would you accept just a clean up for the variable names in this patch? I could then add the pass by reference when I add the new fields later. Or would an update to the commit message be ok to land this now? Ira > > Thanks > > tglx >