From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Gleixner Subject: Re: [PATCH v3 01/22] timer: Allow to check when the timer callback has not finished yet Date: Wed, 18 Nov 2015 23:32:28 +0100 (CET) Message-ID: References: <1447853127-3461-1-git-send-email-pmladek@suse.com> <1447853127-3461-2-git-send-email-pmladek@suse.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: In-Reply-To: <1447853127-3461-2-git-send-email-pmladek@suse.com> Sender: owner-linux-mm@kvack.org To: Petr Mladek Cc: Andrew Morton , Oleg Nesterov , Tejun Heo , Ingo Molnar , Peter Zijlstra , Steven Rostedt , "Paul E. McKenney" , Josh Triplett , Linus Torvalds , Jiri Kosina , Borislav Petkov , Michal Hocko , linux-mm@kvack.org, Vlastimil Babka , linux-api@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-api@vger.kernel.org On Wed, 18 Nov 2015, Petr Mladek wrote: > timer_pending() checks whether the list of callbacks is empty. > Each callback is removed from the list before it is called, > see call_timer_fn() in __run_timers(). > > Sometimes we need to make sure that the callback has finished. > For example, if we want to free some resources that are accessed > by the callback. > > For this purpose, this patch adds timer_active(). It checks both > the list of callbacks and the running_timer. It takes the base_lock > to see a consistent state. > > I plan to use it to implement delayed works in kthread worker. > But I guess that it will have wider use. In fact, I wonder if > timer_pending() is misused in some situations. Well. That's nice and good. But how will that new function solve anything? After you drop the lock the state is not longer valid. Thanks, tglx -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org