NOTE:This is a prerequisite patch that's required to address the widely observed leap-second related futex/hrtimer issues.
Currently clock_was_set() is unsafe to be called from atomic context, as it calls on_each_cpu(). This causes problems when we need to adjust the time from update_wall_time(). To fix this, introduce a work_struct so if we're in_atomic, we can schedule work to do the necessary update after we're out of the atomic section. CC: Prarit Bhargava <[email protected]> CC: [email protected] CC: Thomas Gleixner <[email protected]> Reported-by: Jan Engelhardt <[email protected]> Signed-off-by: John Stultz <[email protected]> --- kernel/hrtimer.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index ae34bf5..ee7a98d 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -746,7 +746,7 @@ static inline void retrigger_next_event(void *arg) { } * resolution timer interrupts. On UP we just disable interrupts and * call the high resolution interrupt code. */ -void clock_was_set(void) +static void do_clock_was_set(struct work_struct *work) { #ifdef CONFIG_HIGH_RES_TIMERS /* Retrigger the CPU local events everywhere */ @@ -754,6 +754,20 @@ void clock_was_set(void) #endif timerfd_clock_was_set(); } +static DECLARE_WORK(clock_was_set_work, do_clock_was_set); + +void clock_was_set(void) +{ + /* + * We can't call on_each_cpu() from atomic context, + * so if we're in_atomic, schedule the clock_was_set + * for later. + */ + if (in_atomic()) + schedule_work(&clock_was_set_work); + else + do_clock_was_set(NULL); +} /* * During resume we might have to reprogram the high resolution timer -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
