From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757912AbcAYSoq (ORCPT ); Mon, 25 Jan 2016 13:44:46 -0500 Received: from mail-pf0-f195.google.com ([209.85.192.195]:35659 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755589AbcAYSol (ORCPT ); Mon, 25 Jan 2016 13:44:41 -0500 Date: Mon, 25 Jan 2016 13:44:38 -0500 From: Tejun Heo To: Petr Mladek Cc: Andrew Morton , Oleg Nesterov , Ingo Molnar , Peter Zijlstra , Steven Rostedt , "Paul E. McKenney" , Josh Triplett , Thomas Gleixner , Linus Torvalds , Jiri Kosina , Borislav Petkov , Michal Hocko , linux-mm@kvack.org, Vlastimil Babka , linux-api@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 01/22] timer: Allow to check when the timer callback has not finished yet Message-ID: <20160125184438.GA3628@mtj.duckdns.org> References: <1453736711-6703-1-git-send-email-pmladek@suse.com> <1453736711-6703-2-git-send-email-pmladek@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1453736711-6703-2-git-send-email-pmladek@suse.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Mon, Jan 25, 2016 at 04:44:50PM +0100, 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. I don't think this is still necessary. More on this later. Thanks. -- tejun From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH v4 01/22] timer: Allow to check when the timer callback has not finished yet Date: Mon, 25 Jan 2016 13:44:38 -0500 Message-ID: <20160125184438.GA3628@mtj.duckdns.org> References: <1453736711-6703-1-git-send-email-pmladek@suse.com> <1453736711-6703-2-git-send-email-pmladek@suse.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1453736711-6703-2-git-send-email-pmladek@suse.com> Sender: owner-linux-mm@kvack.org To: Petr Mladek Cc: Andrew Morton , Oleg Nesterov , Ingo Molnar , Peter Zijlstra , Steven Rostedt , "Paul E. McKenney" , Josh Triplett , Thomas Gleixner , 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 Hello, On Mon, Jan 25, 2016 at 04:44:50PM +0100, 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. I don't think this is still necessary. More on this later. Thanks. -- tejun -- 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