lockdep/proc: Fix lock-time avg computation

>    kernel/locking/lockdep_proc.c: In function 'seq_lock_time':
> >> kernel/locking/lockdep_proc.c:424:23: warning: comparison of distinct pointer types lacks a cast [enabled by default]
>
>    418	static void seq_lock_time(struct seq_file *m, struct lock_time *lt)
>    419	{
>    420		seq_printf(m, "%14lu", lt->nr);
>    421		seq_time(m, lt->min);
>    422		seq_time(m, lt->max);
>    423		seq_time(m, lt->total);
>  > 424		seq_time(m, lt->nr ? do_div(lt->total, lt->nr) : 0);
>    425	}

My compiler refuses to actually say that; but it looks wrong in that
do_div() returns the remainder, not the divisor.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Tested-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Link: http://lkml.kernel.org/r/20131106164230.GE16117@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c
index 0922065..ef43ac4 100644 (file)
--- a/kernel/locking/lockdep_proc.c
+++ b/kernel/locking/lockdep_proc.c
@@ -421,7 +421,7 @@ static void seq_lock_time(struct seq_file *m, struct lock_time *lt)
        seq_time(m, lt->min);
        seq_time(m, lt->max);
        seq_time(m, lt->total);
-       seq_time(m, lt->nr ? do_div(lt->total, lt->nr) : 0);
+       seq_time(m, lt->nr ? div_s64(lt->total, lt->nr) : 0);
 }
 
 static void seq_stats(struct seq_file *m, struct lock_stat_data *data)