Commit 960c65e8 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Paul Mundt
Browse files

sh: fix xtime_lock deadlocking. 



move update_process_times() out from under xtime_lock.

Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent 9216f194

arch/sh/kernel/time_32.c

+15 −4
Original line number Diff line number Diff line
@@ -120,10 +120,6 @@ static long last_rtc_update; 
 */

void handle_timer_tick(void)

{

	do_timer(1);

#ifndef CONFIG_SMP

	update_process_times(user_mode(get_irq_regs()));

#endif

	if (current->pid)

		profile_tick(CPU_PROFILING);
@@ -132,6 +128,16 @@ void handle_timer_tick(void) 
		sh_mv.mv_heartbeat();

#endif



	/*

	 * Here we are in the timer irq handler. We just have irqs locally

	 * disabled but we don't know if the timer_bh is running on the other

	 * CPU. We need to avoid to SMP race with it. NOTE: we don' t need

	 * the irq version of write_lock because as just said we have irq

	 * locally disabled. -arca

	 */

	write_seqlock(&xtime_lock);

	do_timer(1);



	/*

	 * If we have an externally synchronized Linux clock, then update

	 * RTC clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
@@ -147,6 +153,11 @@ void handle_timer_tick(void) 
			/* do it again in 60s */

			last_rtc_update = xtime.tv_sec - 600;

	}

	write_sequnlock(&xtime_lock);



#ifndef CONFIG_SMP

	update_process_times(user_mode(get_irq_regs()));

#endif

}

#endif /* !CONFIG_GENERIC_CLOCKEVENTS */

arch/sh/kernel/time_64.c

+17 −14
Original line number Diff line number Diff line
@@ -229,15 +229,22 @@ static long last_rtc_update; 
static inline void do_timer_interrupt(void)

{

	unsigned long long current_ctc;



	if (current->pid)

		profile_tick(CPU_PROFILING);



	/*

	 * Here we are in the timer irq handler. We just have irqs locally

	 * disabled but we don't know if the timer_bh is running on the other

	 * CPU. We need to avoid to SMP race with it. NOTE: we don' t need

	 * the irq version of write_lock because as just said we have irq

	 * locally disabled. -arca

	 */

	write_lock(&xtime_lock);

	asm ("getcon cr62, %0" : "=r" (current_ctc));

	ctc_last_interrupt = (unsigned long) current_ctc;



	do_timer(1);

#ifndef CONFIG_SMP

	update_process_times(user_mode(get_irq_regs()));

#endif

	if (current->pid)

		profile_tick(CPU_PROFILING);



#ifdef CONFIG_HEARTBEAT

	if (sh_mv.mv_heartbeat != NULL)
@@ -259,6 +266,11 @@ static inline void do_timer_interrupt(void) 
			/* do it again in 60 s */

			last_rtc_update = xtime.tv_sec - 600;

	}

	write_unlock(&xtime_lock);



#ifndef CONFIG_SMP

	update_process_times(user_mode(get_irq_regs()));

#endif

}



/*
@@ -275,16 +287,7 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id) 
	timer_status &= ~0x100;

	ctrl_outw(timer_status, TMU0_TCR);



	/*

	 * Here we are in the timer irq handler. We just have irqs locally

	 * disabled but we don't know if the timer_bh is running on the other

	 * CPU. We need to avoid to SMP race with it. NOTE: we don' t need

	 * the irq version of write_lock because as just said we have irq

	 * locally disabled. -arca

	 */

	write_lock(&xtime_lock);

	do_timer_interrupt();

	write_unlock(&xtime_lock);



	return IRQ_HANDLED;

}