From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sebastian Andrzej Siewior Subject: Re: [RFC PATCH] tasklet: correct the comments about tasklet schedule Date: Thu, 26 Feb 2015 15:35:55 +0100 Message-ID: <20150226143555.GG12992@linutronix.de> References: <536075C1.2080704@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: Steven Rostedt , mingo@kernel.org, linux-rt-users , zhangwei , Li Zefan , peterz@infradead.org To: Qiang Huang Return-path: Received: from www.linutronix.de ([62.245.132.108]:49212 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753432AbbBZOf7 (ORCPT ); Thu, 26 Feb 2015 09:35:59 -0500 Content-Disposition: inline In-Reply-To: <536075C1.2080704@huawei.com> Sender: linux-rt-users-owner@vger.kernel.org List-ID: * Qiang Huang | 2014-04-30 12:02:09 [+0800]: >--- a/include/linux/interrupt.h >+++ b/include/linux/interrupt.h >@@ -514,9 +514,8 @@ extern void __send_remote_softirq(struct call_single_data *cp, int cpu, > to be executed on some cpu at least once after this. > * If the tasklet is already scheduled, but its execution is still not > started, it will be executed only once. >- * If this tasklet is already running on another CPU, it is rescheduled >- for later. This is true >- * Schedule must not be called from the tasklet itself (a lockup occurs) This is true >+ * If this tasklet is already running on another CPU (or schedule is called >+ from tasklet itself), it wound not be rescheduled. that are two statements. I suggest you fix the driver instead poking at the tasklet code. > * Tasklet is strictly serialized wrt itself, but not > wrt another tasklets. If client needs some intertask synchronization, > he makes it with spinlocks. Sebastian