*/
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);
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
/* 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 */