On Fri, Nov 24, 2017 at 04:58:16PM +0100, Petr Mladek wrote: > @@ -1797,13 +1797,6 @@ asmlinkage int vprintk_emit(int facility, int level, > spin_release(&console_owner_dep_map, 1, > _THIS_IP_); > printk_safe_exit_irqrestore(flags); > > - /* > - * The owner passed the console lock to us. > - * Since we did not spin on console lock, > annotate > - * this as a trylock. Otherwise lockdep will > - * complain. > - */ > - mutex_acquire(&console_lock_dep_map, 0, 1, > _THIS_IP_);
Hello Petr, IMHO, it would get unbalanced if you only remove this mutex_acquire(). > console_unlock(); > printk_safe_enter_irqsave(flags); > } > @@ -2334,10 +2327,10 @@ void console_unlock(void) > /* The waiter is now free to continue */ > spin_release(&console_owner_dep_map, 1, _THIS_IP_); > /* > - * Hand off console_lock to waiter. The waiter will perform > - * the up(). After this, the waiter is the console_lock owner. > + * Hand off console_lock to waiter. After this, the waiter > + * is the console_lock owner. > */ > - mutex_release(&console_lock_dep_map, 1, _THIS_IP_); IMHO, this release() should be moved to somewhere properly. > + lock_commit_crosslock((struct lockdep_map > *)&console_lock_dep_map); > printk_safe_exit_irqrestore(flags); > /* Note, if waiter is set, logbuf_lock is not held */ > return; However, now that cross-release was introduces, lockdep can be applied to semaphore operations. Actually, I have a plan to do that. I think it would be better to make semaphore tracked with lockdep and remove all these manual acquire() and release() here. What do you think about it? Thanks, Byungchul
