From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Subject: Re: [RFC PATCH 09/18] kthread: Make it easier to correctly sleep in iterant kthreads Date: Wed, 10 Jun 2015 10:07:29 -0400 Message-ID: <20150610100729.6a674c15@gandalf.local.home> References: <1433516477-5153-1-git-send-email-pmladek@suse.cz> <1433516477-5153-10-git-send-email-pmladek@suse.cz> <20150605161021.GJ19282@twins.programming.kicks-ass.net> <20150608134810.3abd862b@gandalf.local.home> <20150610090724.GD3644@twins.programming.kicks-ass.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20150610090724.GD3644@twins.programming.kicks-ass.net> Sender: linux-kernel-owner@vger.kernel.org To: Peter Zijlstra Cc: Petr Mladek , Andrew Morton , Oleg Nesterov , Tejun Heo , Ingo Molnar , Richard Weinberger , David Woodhouse , linux-mtd@lists.infradead.org, Trond Myklebust , Anna Schumaker , linux-nfs@vger.kernel.org, Chris Mason , "Paul E. McKenney" , Thomas Gleixner , Linus Torvalds , Jiri Kosina , Borislav Petkov , Michal Hocko , live-patching@vger.kernel.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-api@vger.kernel.org On Wed, 10 Jun 2015 11:07:24 +0200 Peter Zijlstra wrote: > > Not to mention, tasks in TASK_UNINTERRUPTIBLE state for too long will > > trigger hung task detection. > > Right, and I had not considered that, but it turns out the hung_task > detector checks p->state == TASK_UNINTERRUPTIBLE, so TASK_IDLE is indeed > safe from that. Also, I would assume that TASK_IDLE only makes sense for kernel threads, I wonder if we should add an assertion in schedule that triggers if a task is scheduling with TASK_IDLE and is not a kernel thread (has its own mm?) -- Steve