[PATCH RT 32/36] timers: Track total number of timers in list

Steven Rostedt
2015-03-12T19:23:41Z

[-- Attachment #1: 0032-timers-Track-total-number-of-timers-in-list.patch --]
[-- Type: text/plain, Size: 2249 bytes --]

3.12.38-rt53-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>

upstream commit: fff421580f512fc044cc7421fdff31a7a6997350

Currently, the tvec_base structure's ->active_timers field tracks only
the non-deferrable timers, which means that even if ->active_timers is
zero, there might well be deferrable timers in the list. This commit
therefore adds an ->all_timers field to track all the timers, whether
deferrable or not.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Tested-by: Mike Galbraith <bitbucket@online.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
kernel/timer.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/kernel/timer.c b/kernel/timer.c
index 3b79da2f9c67..1f1795734b70 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -84,6 +84,7 @@ struct tvec_base {
unsigned long timer_jiffies;
unsigned long next_timer;
unsigned long active_timers;
+ unsigned long all_timers;
struct tvec_root tv1;
struct tvec tv2;
struct tvec tv3;
@@ -395,6 +396,7 @@ static void internal_add_timer(struct tvec_base *base, struct timer_list *timer)
base->next_timer = timer->expires;
base->active_timers++;
}
+ base->all_timers++;
}

#ifdef CONFIG_TIMER_STATS
@@ -674,6 +676,7 @@ detach_expired_timer(struct timer_list *timer, struct tvec_base *base)
detach_timer(timer, true);
if (!tbase_get_deferrable(timer->base))
base->active_timers--;
+ base->all_timers--;
}

static int detach_if_pending(struct timer_list *timer, struct tvec_base *base,
@@ -688,6 +691,7 @@ static int detach_if_pending(struct timer_list *timer, struct tvec_base *base,
if (timer->expires == base->next_timer)
base->next_timer = base->timer_jiffies;
}
+ base->all_timers--;
return 1;
}

@@ -1678,6 +1682,7 @@ static int init_timers_cpu(int cpu)
base->timer_jiffies = jiffies;
base->next_timer = base->timer_jiffies;
base->active_timers = 0;
+ base->all_timers = 0;
return 0;
}

--
2.1.4