Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752576AbbDWHB1 (ORCPT ); Thu, 23 Apr 2015 03:01:27 -0400 Received: from mail-wg0-f48.google.com ([74.125.82.48]:36432 "EHLO mail-wg0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750813AbbDWHBZ (ORCPT ); Thu, 23 Apr 2015 03:01:25 -0400 Message-ID: <1429772482.3419.40.camel@gmail.com> Subject: Re: [PATCH RT 3.18] irq_work: Provide a soft-irq based queue From: Mike Galbraith To: Jan Kiszka Cc: Steven Rostedt , Sebastian Andrzej Siewior , RT , Linux Kernel Mailing List Date: Thu, 23 Apr 2015 09:01:22 +0200 In-Reply-To: <55389632.50308@siemens.com> References: <552FC1FE.4020406@siemens.com> <552FC6B1.1040000@linutronix.de> <552FC72A.8060709@siemens.com> <20150416111041.66043164@gandalf.local.home> <552FD55F.8000105@siemens.com> <552FE320.6050601@siemens.com> <1429517036.3226.9.camel@gmail.com> <1429769505.3419.9.camel@gmail.com> <55389632.50308@siemens.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.16.0 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1568 Lines: 46 On Thu, 2015-04-23 at 08:50 +0200, Jan Kiszka wrote: > On 2015-04-23 08:11, Mike Galbraith wrote: > > @@ -103,6 +98,9 @@ EXPORT_SYMBOL_GPL(irq_work_queue_on); > > /* Enqueue the irq work @work on the current CPU */ > > bool irq_work_queue(struct irq_work *work) > > { > > + bool realtime = IS_ENABLED(CONFIG_PREEMPT_RT_FULL); > > + bool raise = false; > > + > > /* Only queue if not already pending */ > > if (!irq_work_claim(work)) > > return false; > > @@ -110,25 +108,22 @@ bool irq_work_queue(struct irq_work *wor > > /* Queue the entry and raise the IPI if needed. */ > > preempt_disable(); > > > > -#ifdef CONFIG_PREEMPT_RT_FULL > > - if (work->flags & IRQ_WORK_HARD_IRQ) { > > + if (realtime && (work->flags & IRQ_WORK_HARD_IRQ)) { > > if (llist_add(&work->llnode, > > this_cpu_ptr(&hirq_work_list))) > > This boils down to > > #ifdef CONFIG_X > some_type x; > #endif > ... > > if (IS_ENABLED(CONFIG_X) && ...) > use(x); > > And here we even have an indirection for IS_ENABLED via that local > bool > variable. Is that pattern OK for Linux? Does it compile in all > supported > optimization levels of all supported compilers? I hope it all goes away, that being what IS_ENABLED() is there for. -Mike -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/