Messages in this thread | | | Date | Wed, 11 Jun 2014 19:17:34 +0200 | From | Oleg Nesterov <> | Subject | Re: safety of *mutex_unlock() (Was: [BUG] signal: sighand unprotected when accessed by /proc) |
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On 06/11, Oleg Nesterov wrote: > > On 06/11, Paul E. McKenney wrote: > > > raw_spin_unlock_irqrestore(&rnp->lock, flags); > > rt_mutex_lock(&mtx); /* Side effect: boosts task t's priority. */ > > rt_mutex_unlock(&mtx); /* Keep lockdep happy. */ > > > > + /* Wait until boostee is done accessing mtx before reinitializing. */ > > + wait_for_completion(&rnp->boost_completion); > > + > > I must have missed something, I dont understand why we need ->boost_completion. > > What if you simply move that rt_mutex into rcu_node ? > > Or. Given that rcu_boost_kthread() never exits, it can declare this mutex > on stack and pass the pointer to rcu_boost() ?
Ah, please ignore, I forgot about init_proxy_locked(). Although perhaps this can be solved easily.
Oleg.
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