Peter Zijlstra <pet...@infradead.org> writes:
> Currently the RCU usage in module is an inconsistent mess of RCU and
> RCU-sched, this is broken for CONFIG_PREEMPT where synchronize_rcu()
> does not imply synchronize_sched().
Huh? It's not "an inconsistent mess". They're all synchronize_rcu(),
except one.
That one is *specifically* a best effort bandaid for the case where
module initialization has failed. It's theoretically racy, so we wait a
bit before freeing.
That said, I love the new checks, thanks!
> +static inline void module_assert_mutex(void)
> +{
> + lockdep_assert_held(&module_mutex);
> +}
> +
> +static inline void module_assert_mutex_or_preempt(void)
> +{
> +#ifdef CONFIG_LOCKDEP
> + int rcu_held = rcu_read_lock_sched_held();
> + int mutex_held = 1;
> +
> + if (debug_locks)
> + mutex_held = lockdep_is_held(&module_mutex);
> +
> + WARN_ON(!rcu_held && !mutex_held);
> +#endif
> +}
Minor nitpick: I generally avoid static inline in C files (unless
functions are unused under some config options, which these aren't).
In general, they mess up future cleanups, as gcc doesn't warn about
unused functions.
Thanks,
Rusty.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
