loops_per_jiffy*Hz is not always 1 second exactly
it depends on the realization of _delay() .
delay_tsc is used as _delay() in arch/x86/lib/delay.c
It makes loop loops_per_jiffy larger than exception
and causes one thread can not obtain the spin lock for
a long time which may trigger HARD LOCKUP in this case.
So we use cpu_clock() which is more accurate.
Signed-off-by: Chuansheng Liu <chuansheng....@intel.com>
Signed-off-by: xiaoming wang <xiaoming.w...@intel.com>
---
kernel/locking/spinlock_debug.c | 9 ++++++---
1 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/kernel/locking/spinlock_debug.c b/kernel/locking/spinlock_debug.c
index 0374a59..471d26c 100644
--- a/kernel/locking/spinlock_debug.c
+++ b/kernel/locking/spinlock_debug.c
@@ -105,10 +105,13 @@ static inline void debug_spin_unlock(raw_spinlock_t *lock)
static void __spin_lock_debug(raw_spinlock_t *lock)
{
- u64 i;
- u64 loops = loops_per_jiffy * HZ;
+ u64 t;
+ u64 one_second = 1000000000;
+ u32 this_cpu = raw_smp_processor_id();
+
+ t = cpu_clock(this_cpu);
- for (i = 0; i < loops; i++) {
+ while (cpu_clock(this_cpu) - t < one_second) {
if (arch_spin_trylock(&lock->raw_lock))
return;
__delay(1);
--
1.7.1
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