From cbe62e2b4a764aa3f9a2b9c9004f8e86a1f0ade8 Mon Sep 17 00:00:00 2001
From: Paul Mackerras <paulus@samba.org>
Date: Thu, 10 Nov 2005 14:28:03 +1100
Subject: [PATCH] powerpc: Fix SMP time initialization problem
We were getting the last_jiffy per-cpu variable set ahead of the current
timebase in smp_space_timers on SMP machines. This caused the loop in
timer_interrupt to loop virtually forever, since tb_ticks_since assumes
that it will never be called with the timebase behind the last_jiffy
value.
Signed-off-by: Paul Mackerras <paulus@samba.org>
---
arch/powerpc/kernel/time.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 386006b3d6160..260b6ecd26a9d 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -484,6 +484,8 @@ void __init smp_space_timers(unsigned int max_cpus)
unsigned long offset = tb_ticks_per_jiffy / max_cpus;
unsigned long previous_tb = per_cpu(last_jiffy, boot_cpuid);
+ /* make sure tb > per_cpu(last_jiffy, cpu) for all cpus always */
+ previous_tb -= tb_ticks_per_jiffy;
for_each_cpu(i) {
if (i != boot_cpuid) {
previous_tb += offset;
--
2.30.2