- Fix the kthread_{suspend, resume, suspend_check}() locking.

  In the current code, the locking is completely broken and may lead
  easilly to deadlocks. Fix it by using the proc_mtx, linked to the
  suspending thread, as lock for the operation.  Keep using the
  thread_lock for setting and reading the flag even if it is not entirely
  necessary (atomic ops may do it as well, but this way the code is more
  readable).
- Fix a deadlock within kthread_suspend().
  The suspender should not sleep on a different channel wrt the suspended
  thread, or, otherwise, the awaker should wakeup both. Uniform the
  interface to what the kproc_* counterparts do (sleeping on the same
  channel).
- Change the kthread_suspend_check() prototype.
  kthread_suspend_check() always assumes curthread and must only refer to
  it, so skip the thread pointer as it may be easilly mistaken.
  If curthread is not a kthread, the system will panic.

In collabouration with:	jhb
Tested by:		Giovanni Trematerra
			<giovanni dot trematerra at gmail dot com>
MFC:			2 weeks

1 files changed, 1 insertions, 1 deletions

diff --git a/sys/sys/kthread.h b/sys/sys/kthread.h
index e4d9c5a..b06ff69 100644
--- a/sys/sys/kthread.h
+++ b/sys/sys/kthread.h
@@ -73,7 +73,7 @@ int	kthread_resume(struct thread *);
 void	kthread_shutdown(void *, int);
 void	kthread_start(const void *);
 int	kthread_suspend(struct thread *, int);
-void	kthread_suspend_check(struct thread *);
+void	kthread_suspend_check(void);
 
 
 #endif /* !_SYS_KTHREAD_H_ */