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=-3.9 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 2B18CC6379D for ; Mon, 16 Nov 2020 17:43:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E4FC920B80 for ; Mon, 16 Nov 2020 17:43:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="ucTY/LVv"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="YP2D9OKy" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387986AbgKPRnG (ORCPT ); Mon, 16 Nov 2020 12:43:06 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:42608 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387829AbgKPRmV (ORCPT ); Mon, 16 Nov 2020 12:42:21 -0500 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1605548539; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=AFtB0Ip6R2EINkfby885/eXKxzn7nAYtOiaas7ShpD8=; b=ucTY/LVv679/wmtLVFj1aWd9sEHqvK298xZYswCwYCPhN8K6/VsSRE7jSBhfryBTJ6Xaec iWZ1KD8vwfG36MTBmhGHCbsUbS3UqdYPBCdHIrK4tFOGGv3o73NqScfF+IuVD7Lx5wNJ4E ct+pvkYNxgjuYfF6W+3H6JhdZW9rLmVSMnAqbJjz3eaXA1ppi8L0brIci6nAcqGV/SzjpO d55eUUUn6T/bNSl1Z/8Nge63sZYpmCqmJJI8znPpt3TuS881D+s7KtqNUyS/qzsi4xUqQ4 RlAO3412YsCCAu+hJz3yg2rDEig4KmlERzF8sx2R4lQkRAVmN9SJ/UqOp1+QOQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1605548539; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=AFtB0Ip6R2EINkfby885/eXKxzn7nAYtOiaas7ShpD8=; b=YP2D9OKyBiwGPh1cJ4lErNx/TU9tcJQ7nALdwz1XvcauQRzGOmay8UWLiYUNw+z1AHChep 2mQNtCDmrth6cPAA== To: Peter Zijlstra Cc: LKML , Frederic Weisbecker , Paul McKenney , Sebastian Andrzej Siewior , Arnd Bergmann , "James E.J. Bottomley" , Helge Deller , linux-parisc@vger.kernel.org, Yoshinori Sato , Rich Felker , linux-sh@vger.kernel.org, Jeff Dike , Richard Weinberger , Anton Ivanov , linux-um@lists.infradead.org, Russell King , Marc Zyngier , Valentin Schneider , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon Subject: Re: [patch 10/19] preempt: Cleanup the macro maze a bit In-Reply-To: <20201116121748.GD3121378@hirez.programming.kicks-ass.net> References: <20201113140207.499353218@linutronix.de> <20201113141733.864469886@linutronix.de> <20201116121748.GD3121378@hirez.programming.kicks-ass.net> Date: Mon, 16 Nov 2020 18:42:19 +0100 Message-ID: <871rgtyz9g.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 16 2020 at 13:17, Peter Zijlstra wrote: > On Fri, Nov 13, 2020 at 03:02:17PM +0100, Thomas Gleixner wrote: > >> -#define irq_count() (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK \ >> - | NMI_MASK)) >> +#define irq_count() (nmi_count() | hardirq_count() | softirq_count()) > > >> +#define in_task() (!(in_nmi() | in_hardirq() | in_serving_softirq())) >> -#define in_task() (!(preempt_count() & \ >> - (NMI_MASK | HARDIRQ_MASK | SOFTIRQ_OFFSET))) > > How horrible is the code-gen? Because preempt_count() is > raw_cpu_read_4() and at least some old compilers will refuse to CSE it > (consider the this_cpu_read_stable mess). I looked at gcc8 and 10 output and the compilers are smart enough to fold it for the !RT case. But yeah ... Thanks, tglx