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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 B69ABC433E0 for ; Wed, 8 Jul 2020 16:18:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C61320786 for ; Wed, 8 Jul 2020 16:18:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="J+G840SU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730551AbgGHQSH (ORCPT ); Wed, 8 Jul 2020 12:18:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38842 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730093AbgGHQSG (ORCPT ); Wed, 8 Jul 2020 12:18:06 -0400 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7CFDDC061A0B for ; Wed, 8 Jul 2020 09:18:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.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=i483IMQSRtR6J+n94GaZZET/X/lONTUJSH/4pcYK8jY=; b=J+G840SUfei8u8CJZHruj5Kw3p 3y3+AoKYPTFfOxz+GtgBh8qi5jW2iVlbQtmMzRgMr8RoWJGpSOD3lE/c6dMxbVmcyfqLr9DeNlura II877bwwbuswXMUl+ISOTvxAZYOiL3Orzu68MXsAaeIazcS9JkP9PTjoHGOTIDypClGe+hKmJMDW6 A6CxpOLrhZNabtMyC9ytQN/33EdSvvx3maKfW4G2qYb98v9IOvS5F8XSlYG8hYnIhvYg4rR74i+PC bz21rFdzdPwUxh+AxTCFWQx34PXItOHPW6s+4udZK6FsVezO/xdoP52liLVhHV+wYvnm+ONGHGpWP DWRPLizw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jtCll-0000lM-Bq; Wed, 08 Jul 2020 16:18:01 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 2E4EE3006D0; Wed, 8 Jul 2020 18:18:00 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 1C3C4214ECDA9; Wed, 8 Jul 2020 18:18:00 +0200 (CEST) Date: Wed, 8 Jul 2020 18:18:00 +0200 From: Peter Zijlstra To: "Ahmed S. Darwish" Cc: Ingo Molnar , Will Deacon , Thomas Gleixner , "Paul E. McKenney" , "Sebastian A. Siewior" , Steven Rostedt , LKML Subject: Re: [PATCH v3 06/20] seqlock: Extend seqcount API with associated locks Message-ID: <20200708161800.GT4800@hirez.programming.kicks-ass.net> References: <20200630054452.3675847-7-a.darwish@linutronix.de> <20200706212148.GE5523@worktop.programming.kicks-ass.net> <20200707084024.GA4097637@debian-buster-darwi.lab.linutronix.de> <20200707130410.GO4800@hirez.programming.kicks-ass.net> <20200707143726.GO117543@hirez.programming.kicks-ass.net> <20200708103314.GB4151780@debian-buster-darwi.lab.linutronix.de> <20200708122938.GQ4800@hirez.programming.kicks-ass.net> <20200708150930.GA147323@debian-buster-darwi.lab.linutronix.de> <20200708153522.GR4800@hirez.programming.kicks-ass.net> <20200708155813.GA147953@debian-buster-darwi.lab.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200708155813.GA147953@debian-buster-darwi.lab.linutronix.de> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 08, 2020 at 05:58:13PM +0200, Ahmed S. Darwish wrote: > > I even considered: > > > > #define __SEQPROP(name, prop, expr) \ > > static __always_inline __seqprop_##prop##_t \ > > __seqprop##name##_##prop(seqcount##name##_t *s) \ > > { \ > > expr; \ > > } > > > > Such that we could write: > > > > __SEQPROP(, ptr, return s) > > __SEQPROP(, preempt, return false) > > __SEQPROP(, assert, ) > > > > __SEQPROP(_##locktype, ptr, return &s->seqcount) \ > > __SEQPROP(_##locktype, preempt, return preempt) \ > > __SEQPROP(_##locktype, assert, __SEQCOUNT_LOCKDEP(lockdep_assert_held(s->lockmember))) \ > > > > But I figured _that_ might've been one step too far ;-) > > Initially I implemented something like this during internal, > pre-upstream, versions of this patch series. We've decided afterwards > that the macro compression level is so high that the whole thing is not > so easily understandable. I've been reading too much tracing code lately... :-) This is only 2 levels of expansion and fits on a single screen.