Since the xtime lock was split into the timekeeping lock and the jiffies lock, we no longer need to call update_wall_time() while holding the jiffies lock.
Thus, this patch splits update_wall_time() out from do_timer(). This allows us to get away from calling clock_was_set_delayed() in update_wall_time() and instead use the standard clock_was_set() call that previously would deadlock, as it causes the jiffies lock to be acquired. Cc: Sasha Levin <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Prarit Bhargava <[email protected]> Cc: Richard Cochran <[email protected]> Cc: Ingo Molnar <[email protected]> Signed-off-by: John Stultz <[email protected]> --- kernel/time/tick-common.c | 1 + kernel/time/tick-internal.h | 1 + kernel/time/tick-sched.c | 1 + kernel/time/timekeeping.c | 19 ++++--------------- 4 files changed, 7 insertions(+), 15 deletions(-) diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c index 64522ec..91c5f27 100644 --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -70,6 +70,7 @@ static void tick_periodic(int cpu) do_timer(1); write_sequnlock(&jiffies_lock); + update_wall_time(); } update_process_times(user_mode(get_irq_regs())); diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h index e2bced5..8329669 100644 --- a/kernel/time/tick-internal.h +++ b/kernel/time/tick-internal.h @@ -155,3 +155,4 @@ static inline int tick_device_is_functional(struct clock_event_device *dev) #endif extern void do_timer(unsigned long ticks); +extern void update_wall_time(void); diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 2afd43f..c58b03d 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -86,6 +86,7 @@ static void tick_do_update_jiffies64(ktime_t now) tick_next_period = ktime_add(last_jiffies_update, tick_period); } write_sequnlock(&jiffies_lock); + update_wall_time(); } /* diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index d62682b..44b7e6b 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -1360,7 +1360,7 @@ static inline void old_vsyscall_fixup(struct timekeeper *tk) * update_wall_time - Uses the current clocksource to increment the wall time * */ -static void update_wall_time(void) +void update_wall_time(void) { struct clocksource *clock; struct timekeeper *real_tk = &timekeeper; @@ -1441,19 +1441,8 @@ static void update_wall_time(void) write_seqcount_end(&timekeeper_seq); out: raw_spin_unlock_irqrestore(&timekeeper_lock, flags); - if (clock_was_set) { - /* - * XXX - I'd rather we just call clock_was_set(), but - * since we're currently holding the jiffies lock, calling - * clock_was_set would trigger an ipi which would then grab - * the jiffies lock and we'd deadlock. :( - * The right solution should probably be droping - * the jiffies lock before calling update_wall_time - * but that requires some rework of the tick sched - * code. - */ - clock_was_set_delayed(); - } + if (clock_set) + clock_was_set(); } /** @@ -1598,7 +1587,6 @@ struct timespec get_monotonic_coarse(void) void do_timer(unsigned long ticks) { jiffies_64 += ticks; - update_wall_time(); calc_global_load(ticks); } @@ -1756,4 +1744,5 @@ void xtime_update(unsigned long ticks) write_seqlock(&jiffies_lock); do_timer(ticks); write_sequnlock(&jiffies_lock); + update_wall_time(); } -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
