With lazy interrupt, we always call __check_irq_replaysome with
decrementers_next_tb to check if we need to replay timer interrupt.
So in hotplug case we also need to set decrementers_next_tb as MAX
to make sure __check_irq_replay don't replay timer interrupt
when return as we expect, otherwise we'll trap here infinitely.
Signed-off-by: Tiejun Chen <tiejun.c...@windriver.com>
---
v1:
* In hotplug case we max decrementers_next_tb to prevent from
replaying timer interrupt for any offline CPU.
arch/powerpc/kernel/time.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 6f6b1cc..127361e 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -494,10 +494,15 @@ void timer_interrupt(struct pt_regs * regs)
set_dec(DECREMENTER_MAX);
/* Some implementations of hotplug will get timer interrupts while
- * offline, just ignore these
+ * offline, just ignore these and we also need to set
+ * decrementers_next_tb as MAX to make sure __check_irq_replay
+ * don't replay timer interrupt when return, otherwise we'll trap
+ * here infinitely :(
*/
- if (!cpu_online(smp_processor_id()))
+ if (!cpu_online(smp_processor_id())) {
+ *next_tb = ~(u64)0;
return;
+ }
/* Conditionally hard-enable interrupts now that the DEC has been
* bumped to its maximum value
--
1.7.9.5
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