Re: [PATCH] debug work struct cancel deadlocks with lockdep

From: Ingo Molnar
Date: Thu Jul 05 2007 - 04:46:01 EST



* Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote:

> +#ifdef CONFIG_LOCKDEP
> + /*
> + * It is permissible to free the struct work_struct
> + * from inside the function that is called from it,
> + * this we need to take into account for lockdep too.
> + * To avoid bogus "held lock freed" warnings as well
> + * as problems when looking into work->lockdep_map,
> + * make a copy and use that here.
> + */
> + struct lockdep_map lockdep_map = work->lockdep_map;
> +#endif

> + lock_acquire(&lockdep_map, 0, 0, 0, 2, _THIS_IP_);
> f(work);
> + lock_release(&lockdep_map, 1, _THIS_IP_);

neat trick :)

Ingo
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/