[PATCH] LOCKDEP: minor fix for debug_show_all_locks()

[PATCH] LOCKDEP: minor fix for debug_show_all_locks()

[sniper]

When we failed to get tasklist_lock eventually (count equals 0),
we should only print " ignoring it.\n", and not print
" locked it.\n" needlessly.

Signed-off-by: Qinghuang Feng <qhfeng.kernel@gmail.com>
---
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index dbda475..12bf812 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -3417,10 +3417,12 @@ retry:
 		}
 		printk(" ignoring it.\n");
 		unlock = 0;
+		goto print_locks;
 	}
 	if (count != 10)
 		printk(" locked it.\n");

+print_locks:
 	do_each_thread(g, p) {
 		/*
 		 * It's not reliable to print a task's held locks

Re: [PATCH] LOCKDEP: minor fix for debug_show_all_locks()

[Ingo Molnar]

* sniper <s3c24xx@gmail.com> wrote:

> When we failed to get tasklist_lock eventually (count equals 0),
> we should only print " ignoring it.\n", and not print
> " locked it.\n" needlessly.

well spotted!

Minor nit:

> --- a/kernel/lockdep.c
> +++ b/kernel/lockdep.c
> @@ -3417,10 +3417,12 @@ retry:
>  		}
>  		printk(" ignoring it.\n");
>  		unlock = 0;
> +		goto print_locks;
>  	}
>  	if (count != 10)
>  		printk(" locked it.\n");
> 
> +print_locks:
>  	do_each_thread(g, p) {

please move the "if (count != 10)" line into the else section of the 
trylock, instead of introducing a label and a goto.

	Ingo

Re: [PATCH] LOCKDEP: minor fix for debug_show_all_locks()

[qinghuang feng]

When we failed to get tasklist_lock eventually (count equals 0),
we should only print " ignoring it.\n", and not print
" locked it.\n" needlessly.

Signed-off-by: Qinghuang Feng <qhfeng.kernel@gmail.com>
---
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index dbda475..6533fd9 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -3417,8 +3417,7 @@ retry:
 		}
 		printk(" ignoring it.\n");
 		unlock = 0;
-	}
-	if (count != 10)
+	} else if (count != 10)
 		printk(" locked it.\n");

 	do_each_thread(g, p) {

Re: [PATCH] LOCKDEP: minor fix for debug_show_all_locks()

[Ingo Molnar]

* qinghuang feng <qhfeng.kernel@gmail.com> wrote:

> When we failed to get tasklist_lock eventually (count equals 0),
> we should only print " ignoring it.\n", and not print
> " locked it.\n" needlessly.
> 
> Signed-off-by: Qinghuang Feng <qhfeng.kernel@gmail.com>
> ---

> diff --git a/kernel/lockdep.c b/kernel/lockdep.c
> index dbda475..6533fd9 100644
> --- a/kernel/lockdep.c
> +++ b/kernel/lockdep.c
> @@ -3417,8 +3417,7 @@ retry:
>  		}
>  		printk(" ignoring it.\n");
>  		unlock = 0;
> -	}
> -	if (count != 10)
> +	} else if (count != 10)
>  		printk(" locked it.\n");
> 

applied to tip/core/urgent, thanks!

note that i've done two small tweaks to the patch:

 - added curly braces to the else branch as well - the convention is 
   to mirror the curly braces of the main branch in such cases.

 - added KERN_CONT for the printk

	Ingo

-------------->
>From 46fec7ac40e452a2ea5e63648d98b6bb2b5898f9 Mon Sep 17 00:00:00 2001
From: qinghuang feng <qhfeng.kernel@gmail.com>
Date: Tue, 28 Oct 2008 17:24:28 +0800
Subject: [PATCH] lockdep: minor fix for debug_show_all_locks()

When we failed to get tasklist_lock eventually (count equals 0),
we should only print " ignoring it.\n", and not print
" locked it.\n" needlessly.

Signed-off-by: Qinghuang Feng <qhfeng.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/lockdep.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index dbda475..11832ac 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -3417,9 +3417,10 @@ retry:
 		}
 		printk(" ignoring it.\n");
 		unlock = 0;
+	} else {
+		if (count != 10)
+			printk(KERN_CONT " locked it.\n");
 	}
-	if (count != 10)
-		printk(" locked it.\n");
 
 	do_each_thread(g, p) {
 		/*