The patch titled
debug workqueue locking sanity
has been added to the -mm tree. Its filename is
debug-workqueue-locking-sanity-v2.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: debug workqueue locking sanity
From: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Workqueue functions should not leak locks, assert so, printing the
last function ran.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Acked-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
include/linux/lockdep.h | 11 +++++++++++
kernel/workqueue.c | 12 ++++++++++++
2 files changed, 23 insertions(+)
diff -puN include/linux/lockdep.h~debug-workqueue-locking-sanity-v2 include/linux/lockdep.h
--- a/include/linux/lockdep.h~debug-workqueue-locking-sanity-v2
+++ a/include/linux/lockdep.h
@@ -243,6 +243,11 @@ extern void lock_release(struct lockdep_
# define INIT_LOCKDEP .lockdep_recursion = 0,
+static inline int lockdep_depth(struct task *tsk)
+{
+ return tsk->lockdep_depth;
+}
+
#else /* !LOCKDEP */
static inline void lockdep_off(void)
@@ -277,6 +282,12 @@ static inline int lockdep_internal(void)
* The class key takes no space if lockdep is disabled:
*/
struct lock_class_key { };
+
+static inline int lockdep_depth(struct task *tsk)
+{
+ return 0;
+}
+
#endif /* !LOCKDEP */
#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_GENERIC_HARDIRQS)
diff -puN kernel/workqueue.c~debug-workqueue-locking-sanity-v2 kernel/workqueue.c
--- a/kernel/workqueue.c~debug-workqueue-locking-sanity-v2
+++ a/kernel/workqueue.c
@@ -29,6 +29,7 @@
#include <linux/kthread.h>
#include <linux/hardirq.h>
#include <linux/mempolicy.h>
+#include <linux/kallsyms.h>
/*
* The per-CPU workqueue (if single thread, we always use the first
@@ -222,6 +223,17 @@ static void run_workqueue(struct cpu_wor
clear_bit(0, &work->pending);
f(data);
+ if (unlikely(in_atomic() || lockdep_depth(current) > 0)) {
+ printk(KERN_ERR "BUG: workqueue leaked lock or atomic: "
+ "%s/0x%08x/%d\n",
+ current->comm, preempt_count(),
+ current->pid);
+ printk(KERN_ERR " last function: ");
+ print_symbol("%s\n", (unsigned long)f);
+ debug_show_held_locks(current);
+ dump_stack();
+ }
+
spin_lock_irqsave(&cwq->lock, flags);
cwq->remove_sequence++;
wake_up(&cwq->work_done);
_
Patches currently in -mm which might be from a.p.zijlstra@xxxxxxxxx are
origin.patch
lockdep-fix-delayacct-locking-bug.patch
sunrpc-add-missing-spin_unlock.patch
bonding-lockdep-annotation.patch
lockdep-annotate-sk_lock-nesting-in-af_bluetooth-v2.patch
grab-swap-token-reordered.patch
new-scheme-to-preempt-swap-token.patch
new-scheme-to-preempt-swap-token-tidy.patch
mm-arch-do_page_fault-vs-in_atomic.patch
mm-pagefault_disableenable.patch
mm-pagefault_disableenable-s390-fix.patch
mm-kummap_atomic-vs-in_atomic.patch
lockdep-annotate-nfs-nfsd-in-kernel-sockets.patch
lockdep-annotate-nfs-nfsd-in-kernel-sockets-tidy.patch
lockdep-fix-ide-proc-interaction.patch
lockdep-spin_lock_irqsave_nested.patch
lockdep-spin_lock_irqsave_nested-fix.patch
lockdep-spin_lock_irqsave_nested-fix-2.patch
lockdep-annotate-bcsp-driver.patch
lockdep-print-current-locks-on-in_atomic-warnings.patch
lockdep-name-some-old-style-locks.patch
debug-workqueue-locking-sanity-v2.patch
tty-signal-tty-locking.patch
tty-signal-tty-locking-3270-fix.patch
do_task_stat-dont-take-tty_mutex.patch
do_acct_process-dont-take-tty_mutex.patch
sys_unshare-remove-a-broken-clone_sighand-code.patch
remove-the-old-bd_mutex-lockdep-annotation.patch
new-bd_mutex-lockdep-annotation.patch
remove-lock_key-approach-to-managing-nested-bd_mutex-locks.patch
simplify-some-aspects-of-bd_mutex-nesting.patch
use-mutex_lock_nested-for-bd_mutex-to-avoid-lockdep-warning.patch
avoid-lockdep-warning-in-md.patch
bdev-fix-bd_part_count-leak.patch
lockdep-annotate-nfsd4-recover-code.patch
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