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Diffstat (limited to 'arch/sh/kernel/time_32.c')
-rw-r--r--arch/sh/kernel/time_32.c19
1 files changed, 15 insertions, 4 deletions
diff --git a/arch/sh/kernel/time_32.c b/arch/sh/kernel/time_32.c
index 2bc04bfee73..7281342c044 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 */