Messages in this thread |  | | | Subject | Re: [RFC/RFT PATCH] sched: automated per tty task groups | | From | Peter Zijlstra <> | | Date | Thu, 21 Oct 2010 13:25:12 +0200 |
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On Thu, 2010-10-21 at 06:51 -0400, Mathieu Desnoyers wrote: > * Mike Galbraith (efault@gmx.de) wrote: > [...] > > +static void > > +autogroup_attach_tty(struct task_struct *p, struct task_group **tg) > > +{ > > + struct tty_struct *tty = p->signal->tty; > > + > > + if (!tty) > > + return; > > + > > + *tg = p->signal->tty->tg; > > +} > > + > > +static inline void > > +autogroup_check_attach(struct task_struct *p, struct task_group **tg) > > +{ > > + if (!sysctl_sched_autogroup_enabled || *tg != &root_task_group || > > + p->sched_class != &fair_sched_class) > > + return; > > + > > + rcu_read_lock(); > > + > > + autogroup_attach_tty(p, tg); > > + > > + rcu_read_unlock(); > > +} > > +
> Meanwhile, a little question about locking here: how is > the read lock supposed to protect from p->signal (and p->signal->tty) > modifications ? What's the locking scheme here ? So maybe just simple > rcu_dereference are missing, or maybe the tsk->sighand->siglock might be > required. In all cases, I feel something is missing there.
Oleg, could you comment?
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