[PATCH 01/10] posix_timers: Fix pre-condition to stop the tick on full dynticks

From: Frederic Weisbecker
Date: Mon Apr 22 2013 - 15:02:42 EST


The test that checks if a CPU can stop its tick from posix CPU
timers angle was mistakenly inverted.

What we want is to prevent the tick from being stopped as long
as the current CPU's task runs a posix CPU timer.

Fix this.

Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Chris Metcalf <cmetcalf@xxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Geoff Levand <geoff@xxxxxxxxxxxxx>
Cc: Gilad Ben Yossef <gilad@xxxxxxxxxxxxx>
Cc: Hakan Akkan <hakanakkan@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Kevin Hilman <khilman@xxxxxxxxxx>
Cc: Li Zhong <zhong@xxxxxxxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
kernel/posix-cpu-timers.c | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index 84d5cb3..42670e9 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -673,12 +673,12 @@ static void posix_cpu_timer_kick_nohz(void)
bool posix_cpu_timers_can_stop_tick(struct task_struct *tsk)
{
if (!task_cputime_zero(&tsk->cputime_expires))
- return true;
+ return false;

if (tsk->signal->cputimer.running)
- return true;
+ return false;

- return false;
+ return true;
}
#else
static inline void posix_cpu_timer_kick_nohz(void) { }
--
1.7.5.4

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