locking/pvqspinlock: Fix a bug in qstat_read()

It's obviously wrong to set stat to NULL. So lets remove it.
Otherwise it is always zero when we check the latency of kick/wake.

Signed-off-by: Pan Xinhui <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Waiman Long <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

diff --git a/kernel/locking/qspinlock_stat.h b/kernel/locking/qspinlock_stat.h
index 22e02530984574a6fee718aad26720516c34d497..b9d0315162540d1236e5e1268f184531d8259114 100644 (file)
--- a/kernel/locking/qspinlock_stat.h
+++ b/kernel/locking/qspinlock_stat.h
@@ -153,7 +153,6 @@ static ssize_t qstat_read(struct file *file, char __user *user_buf,
                 */
                if ((counter == qstat_pv_latency_kick) ||
                    (counter == qstat_pv_latency_wake)) {
-                       stat = 0;
                        if (kicks)
                                stat = DIV_ROUND_CLOSEST_ULL(stat, kicks);
                }