locking/pvqspinlock: Fix a bug in qstat_read()

Pan Xinhui · Ingo Molnar · commit c2ace36b884d · 2016-08-10T14:13:29.000+02:00
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 <xinhui.pan@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Waiman Long <Waiman.Long@hpe.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1468405414-3700-1-git-send-email-xinhui.pan@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git 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);
 		}

Original file line number	Diff line number	Diff line change
`@@ -153,7 +153,6 @@ static ssize_t qstat_read(struct file file, char __user user_buf,`
`153`	`153`	`*/`
`154`	`154`	`if ((counter == qstat_pv_latency_kick) \|\|`
`155`	`155`	`(counter == qstat_pv_latency_wake)) {`
`156`		`- stat = 0;`
`157`	`156`	`if (kicks)`
`158`	`157`	`stat = DIV_ROUND_CLOSEST_ULL(stat, kicks);`
`159`	`158`	`}`