From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [PATCH RT 3.18] irq_work: Provide a soft-irq based queue Date: Thu, 23 Apr 2015 08:50:26 +0200 Message-ID: <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> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: Steven Rostedt , Sebastian Andrzej Siewior , RT , Linux Kernel Mailing List To: Mike Galbraith Return-path: In-Reply-To: <1429769505.3419.9.camel@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-rt-users.vger.kernel.org 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? Jan -- Siemens AG, Corporate Technology, CT RTC ITP SES-DE Corporate Competence Center Embedded Linux