From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Galbraith Subject: [patch-rt] hotplug, hrtimer: Migrate expired/deferred timers during cpu offline Date: Fri, 11 Aug 2017 09:55:16 +0200 Message-ID: <1502438116.16425.18.camel@gmx.de> References: <20170804173823.lzuhnejlnxczr2lj@linutronix.de> <1501913583.7917.42.camel@gmx.de> <1501945043.5473.31.camel@gmx.de> <20170807073350.nwytftryfp34mrwi@linutronix.de> <1502094121.5568.22.camel@gmx.de> <1502186459.8042.31.camel@gmx.de> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Thomas Gleixner , LKML , linux-rt-users , Steven Rostedt To: Sebastian Andrzej Siewior Return-path: In-Reply-To: <1502186459.8042.31.camel@gmx.de> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-rt-users.vger.kernel.org The below fixes the list debug explosion up. If we do not migrate expired/deferred timers during cpu offline, ->cb_entry will be corrupted by online initialization of base->expired, leading to a loud list debug complaint should someone call __remove_hrtimer() thereafter. Signed-off-by: Mike Galvraith --- kernel/time/hrtimer.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -1802,6 +1802,19 @@ static void migrate_hrtimer_list(struct */ enqueue_hrtimer(timer, new_base); } + + /* + * Finally, migrate any expired timers deferred by RT. + */ + while (!list_empty(&old_base->expired)) { + struct list_head *entry = old_base->expired.next; + + timer = container_of(entry, struct hrtimer, cb_entry); + /* XXX: hm, perhaps defer again instead of enqueueing. */ + __remove_hrtimer(timer, old_base, HRTIMER_STATE_ENQUEUED, 0); + timer->base = new_base; + enqueue_hrtimer(timer, new_base); + } } int hrtimers_dead_cpu(unsigned int scpu)