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| author | Jason Baron <jbaron@redhat.com> | 2007-02-10 12:44:59 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-02-11 21:51:26 +0300 |
| commit | 068135e63518314d4efd711142f674ad0841599e (patch) | |
| tree | dbf8193b0e8f3b6c0e735b48c1f8201a6df207ac /kernel/lockdep.c | |
| parent | 381a229209aa6f7f72375797b7bcfcfe2ae6fcbb (diff) | |
| download | linux-068135e63518314d4efd711142f674ad0841599e.tar.xz | |
[PATCH] lockdep: add graph depth information to /proc/lockdep
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@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/lockdep.c')
| -rw-r--r-- | kernel/lockdep.c | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 2d616f4d853c..592c576d77a7 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -490,7 +490,7 @@ static void print_lock_dependencies(struct lock_class *class, int depth) * 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_class *class, struct lock_class *this, 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, struct held_lock *next, */ 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, struct held_lock *prev, * 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, struct held_lock *prev, * 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, struct held_lock *next) 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, @@ -2779,4 +2785,3 @@ void debug_show_held_locks(struct task_struct *task) } EXPORT_SYMBOL_GPL(debug_show_held_locks); - |