diff options
Diffstat (limited to 'arch/sh/kernel/time_32.c')
| -rw-r--r-- | arch/sh/kernel/time_32.c | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/arch/sh/kernel/time_32.c b/arch/sh/kernel/time_32.c index 2bc04bfee738..7281342c044d 100644 --- a/arch/sh/kernel/time_32.c +++ b/arch/sh/kernel/time_32.c @@ -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); @@ -133,6 +129,16 @@ void handle_timer_tick(void) #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 * called as close as possible to 500 ms before the new second starts. @@ -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 */ |