From: Peter Zijlstra <peterz@infradead.org>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Darren Hart <darren@dvhart.com>,
Thomas Gleixner <tglx@linutronix.de>,
Jerome Marchand <jmarchan@redhat.com>,
Larry Woodman <lwoodman@redhat.com>,
Mateusz Guzik <mguzik@redhat.com>,
linux-kernel@vger.kernel.org,
Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
Pavel Emelyanov <xemul@parallels.com>
Subject: Re: [PATCH 1/1] futex: don't spin waiting for PF_EXITING -> PF_EXITPIDONE transition
Date: Fri, 27 Feb 2015 12:54:28 +0100 [thread overview]
Message-ID: <20150227115428.GA24151@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <20150227095240.GO5029@twins.programming.kicks-ass.net>
On Fri, Feb 27, 2015 at 10:52:40AM +0100, Peter Zijlstra wrote:
> On Mon, Feb 16, 2015 at 09:13:36PM +0100, Oleg Nesterov wrote:
>
> > diff --git a/kernel/futex.c b/kernel/futex.c
> > index b101381..c1104a8 100644
> > +++ b/kernel/futex.c
> > @@ -716,11 +716,13 @@ void exit_pi_state_list(struct task_struct *curr)
> >
> > if (!futex_cmpxchg_enabled)
> > return;
> > +
> > /*
> > + * attach_to_pi_owner() can no longer add the new entry. But
> > + * we have to be careful versus waiters unqueueing themselves.
> > */
> > + curr->flags |= PF_EXITPIDONE;
> > +
> > raw_spin_lock_irq(&curr->pi_lock);
> > while (!list_empty(head)) {
> >
>
> Should we not set PF_EXITPIDONE _inside_ the pi_lock? To properly
> serialize against the below check?
It does not matter, n/m.
prev parent reply other threads:[~2015-02-27 11:54 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-02 14:05 [PATCH 0/1] futex: check PF_KTHREAD rather than !p->mm to filter out kthreads Oleg Nesterov
2015-02-02 14:05 ` [PATCH 1/1] " Oleg Nesterov
2015-02-04 10:48 ` Peter Zijlstra
2015-02-14 18:01 ` Davidlohr Bueso
2015-02-14 20:57 ` Oleg Nesterov
2015-02-14 21:15 ` Davidlohr Bueso
2015-02-14 21:54 ` Oleg Nesterov
2015-02-18 17:11 ` [tip:locking/core] locking/futex: Check " tip-bot for Oleg Nesterov
2015-02-02 15:11 ` [PATCH 0/1] futex: check " Peter Zijlstra
2015-02-02 15:13 ` Peter Zijlstra
2015-02-02 15:14 ` Peter Zijlstra
2015-02-02 16:20 ` Oleg Nesterov
2015-02-03 20:09 ` Oleg Nesterov
2015-02-04 11:12 ` Peter Zijlstra
2015-02-04 20:25 ` Oleg Nesterov
2015-02-05 16:27 ` Peter Zijlstra
2015-02-05 18:10 ` Oleg Nesterov
2015-02-06 10:46 ` Peter Zijlstra
2015-02-06 17:04 ` Oleg Nesterov
2015-02-09 20:38 ` Darren Hart
2015-02-10 11:14 ` Oleg Nesterov
2015-02-16 20:13 ` [PATCH 0/1] futex: don't spin waiting for PF_EXITING -> PF_EXITPIDONE transition Oleg Nesterov
2015-02-16 20:13 ` [PATCH 1/1] " Oleg Nesterov
2015-02-27 9:52 ` Peter Zijlstra
2015-02-27 11:54 ` Peter Zijlstra [this message]
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