The patch titled
lockdep: add graph depth information to /proc/lockdep
has been added to the -mm tree. Its filename is
lockdep-add-graph-depth-information-to-proc-lockdep.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: lockdep: add graph depth information to /proc/lockdep
From: Jason Baron <jbaron@xxxxxxxxxx>
Generate locking graph information into /proc/lockdep, for lock hierarchy
documentation and visualization purposes.
sample output:
c089fd5c OPS: 138 FD: 14 BD: 1 --..: &tty->termios_mutex
-> [c07a3430] tty_ldisc_lock
-> [c07a37f0] &port_lock_key
-> [c07afdc0] &rq->rq_lock_key#2
The lock classes listed are all the first-hop lock dependencies that
lockdep has seen so far.
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
include/linux/lockdep.h | 1
kernel/lockdep.c | 19 +++++++++++------
kernel/lockdep_proc.c | 41 ++++++++++++++++++++++++++------------
3 files changed, 42 insertions(+), 19 deletions(-)
diff -puN include/linux/lockdep.h~lockdep-add-graph-depth-information-to-proc-lockdep include/linux/lockdep.h
--- a/include/linux/lockdep.h~lockdep-add-graph-depth-information-to-proc-lockdep
+++ a/include/linux/lockdep.h
@@ -132,6 +132,7 @@ struct lock_list {
struct list_head entry;
struct lock_class *class;
struct stack_trace trace;
+ int distance;
};
/*
diff -puN kernel/lockdep.c~lockdep-add-graph-depth-information-to-proc-lockdep kernel/lockdep.c
--- a/kernel/lockdep.c~lockdep-add-graph-depth-information-to-proc-lockdep
+++ a/kernel/lockdep.c
@@ -490,7 +490,7 @@ static void print_lock_dependencies(stru
* Add a new dependency to the head of the list:
*/
static int add_lock_to_list(struct lock_class *class, struct lock_class *this,
- struct list_head *head, unsigned long ip)
+ struct list_head *head, unsigned long ip, int distance)
{
struct lock_list *entry;
/*
@@ -502,6 +502,7 @@ static int add_lock_to_list(struct lock_
return 0;
entry->class = this;
+ entry->distance = distance;
if (!save_trace(&entry->trace))
return 0;
@@ -906,7 +907,7 @@ check_deadlock(struct task_struct *curr,
*/
static int
check_prev_add(struct task_struct *curr, struct held_lock *prev,
- struct held_lock *next)
+ struct held_lock *next, int distance)
{
struct lock_list *entry;
int ret;
@@ -984,8 +985,11 @@ check_prev_add(struct task_struct *curr,
* L2 added to its dependency list, due to the first chain.)
*/
list_for_each_entry(entry, &prev->class->locks_after, entry) {
- if (entry->class == next->class)
+ if (entry->class == next->class) {
+ if (distance == 1)
+ entry->distance = 1;
return 2;
+ }
}
/*
@@ -993,12 +997,13 @@ check_prev_add(struct task_struct *curr,
* to the previous lock's dependency list:
*/
ret = add_lock_to_list(prev->class, next->class,
- &prev->class->locks_after, next->acquire_ip);
+ &prev->class->locks_after, next->acquire_ip, distance);
+
if (!ret)
return 0;
ret = add_lock_to_list(next->class, prev->class,
- &next->class->locks_before, next->acquire_ip);
+ &next->class->locks_before, next->acquire_ip, distance);
if (!ret)
return 0;
@@ -1046,13 +1051,14 @@ check_prevs_add(struct task_struct *curr
goto out_bug;
for (;;) {
+ int distance = curr->lockdep_depth - depth + 1;
hlock = curr->held_locks + depth-1;
/*
* Only non-recursive-read entries get new dependencies
* added:
*/
if (hlock->read != 2) {
- if (!check_prev_add(curr, hlock, next))
+ if (!check_prev_add(curr, hlock, next, distance))
return 0;
/*
* Stop after the first non-trylock entry,
@@ -2775,4 +2781,3 @@ void debug_show_held_locks(struct task_s
}
EXPORT_SYMBOL_GPL(debug_show_held_locks);
-
diff -puN kernel/lockdep_proc.c~lockdep-add-graph-depth-information-to-proc-lockdep kernel/lockdep_proc.c
--- a/kernel/lockdep_proc.c~lockdep-add-graph-depth-information-to-proc-lockdep
+++ a/kernel/lockdep_proc.c
@@ -77,12 +77,29 @@ static unsigned long count_backward_deps
return ret;
}
+static void print_name(struct seq_file *m, struct lock_class *class)
+{
+ char str[128];
+ const char *name = class->name;
+
+ if (!name) {
+ name = __get_key_name(class->key, str);
+ seq_printf(m, "%s", name);
+ } else{
+ seq_printf(m, "%s", name);
+ if (class->name_version > 1)
+ seq_printf(m, "#%d", class->name_version);
+ if (class->subclass)
+ seq_printf(m, "/%d", class->subclass);
+ }
+}
+
static int l_show(struct seq_file *m, void *v)
{
unsigned long nr_forward_deps, nr_backward_deps;
struct lock_class *class = m->private;
- char str[128], c1, c2, c3, c4;
- const char *name;
+ struct lock_list *entry;
+ char c1, c2, c3, c4;
seq_printf(m, "%p", class->key);
#ifdef CONFIG_DEBUG_LOCKDEP
@@ -97,16 +114,16 @@ static int l_show(struct seq_file *m, vo
get_usage_chars(class, &c1, &c2, &c3, &c4);
seq_printf(m, " %c%c%c%c", c1, c2, c3, c4);
- name = class->name;
- if (!name) {
- name = __get_key_name(class->key, str);
- seq_printf(m, ": %s", name);
- } else{
- seq_printf(m, ": %s", name);
- if (class->name_version > 1)
- seq_printf(m, "#%d", class->name_version);
- if (class->subclass)
- seq_printf(m, "/%d", class->subclass);
+ seq_printf(m, ": ");
+ print_name(m, class);
+ seq_puts(m, "\n");
+
+ list_for_each_entry(entry, &class->locks_after, entry) {
+ if (entry->distance == 1) {
+ seq_printf(m, " -> [%p] ", entry->class);
+ print_name(m, entry->class);
+ seq_puts(m, "\n");
+ }
}
seq_puts(m, "\n");
_
Patches currently in -mm which might be from jbaron@xxxxxxxxxx are
lockdep-add-graph-depth-information-to-proc-lockdep.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
