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sh: fix xtime_lock deadlocking.

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move update_process_times() out from under xtime_lock.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This commit is contained in:
Peter Zijlstra
2008-02-07 15:01:26 +09:00
committed by Paul Mundt
parent 9216f194e4
commit 960c65e884
2 changed files with 32 additions and 18 deletions
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19
arch/sh/kernel/time_32.c
View File

@ -120,10 +120,6 @@ static long last_rtc_update;
*/ */
void handle_timer_tick(void) void handle_timer_tick(void)
{ {
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(get_irq_regs()));
#endif
if (current->pid) if (current->pid)
profile_tick(CPU_PROFILING); profile_tick(CPU_PROFILING);
@ -132,6 +128,16 @@ void handle_timer_tick(void)
sh_mv.mv_heartbeat(); sh_mv.mv_heartbeat();
#endif #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 * If we have an externally synchronized Linux clock, then update
* RTC clock accordingly every ~11 minutes. Set_rtc_mmss() has to be * 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 */ /* do it again in 60s */
last_rtc_update = xtime.tv_sec - 600; 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 */ #endif /* !CONFIG_GENERIC_CLOCKEVENTS */

31
arch/sh/kernel/time_64.c
View File

@ -229,15 +229,22 @@ static long last_rtc_update;
static inline void do_timer_interrupt(void) static inline void do_timer_interrupt(void)
{ {
unsigned long long current_ctc; 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)); asm ("getcon cr62, %0" : "=r" (current_ctc));
ctc_last_interrupt = (unsigned long) current_ctc; ctc_last_interrupt = (unsigned long) current_ctc;
do_timer(1); 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 #ifdef CONFIG_HEARTBEAT
if (sh_mv.mv_heartbeat != NULL) if (sh_mv.mv_heartbeat != NULL)
@ -259,6 +266,11 @@ static inline void do_timer_interrupt(void)
/* do it again in 60 s */ /* do it again in 60 s */
last_rtc_update = xtime.tv_sec - 600; 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; timer_status &= ~0x100;
ctrl_outw(timer_status, TMU0_TCR); 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(); do_timer_interrupt();
write_unlock(&xtime_lock);
return IRQ_HANDLED; return IRQ_HANDLED;
} }