From: Peter Zijlstra <peterz@infradead.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>,
mingo@kernel.org, juri.lelli@arm.com, xlpang@redhat.com,
bigeasy@linutronix.de, linux-kernel@vger.kernel.org,
mathieu.desnoyers@efficios.com, jdesfossez@efficios.com,
bristot@redhat.com, Ingo Molnar <mingo@redhat.com>
Subject: Re: [PATCH -v2 1/9] rtmutex: Deboost before waking up the top waiter
Date: Thu, 29 Sep 2016 16:49:37 +0200 [thread overview]
Message-ID: <20160929144937.GA5016@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <alpine.DEB.2.20.1609291034390.4825@nanos>
On Thu, Sep 29, 2016 at 10:43:54AM -0400, Thomas Gleixner wrote:
> On Mon, 26 Sep 2016, Peter Zijlstra wrote:
>
> > On Mon, Sep 26, 2016 at 11:37:27AM -0400, Steven Rostedt wrote:
> > > On Mon, 26 Sep 2016 11:35:03 -0400
> > > Steven Rostedt <rostedt@goodmis.org> wrote:
> > >
> > > > Especially now that the code after the spin_unlock(&hb->lock) is now a
> > > > critical section (preemption is disable). There's nothing obvious in
> > > > futex.c that says it is.
> > >
> > > Not to mention, this looks like it will break PREEMPT_RT as wake_up_q()
> > > calls sleepable spin locks.
> >
> > What locks would that be?
>
> None :)
>
> It still breaks RT in the futex case due to:
>
> deboost = rt_mutex_futex_unlock();
>
> spin_unlock(&hb->lock);
> ....
Yeah, noticed that already. Am currently trying to untangle the pi_state
locking rules.
next prev parent reply other threads:[~2016-09-29 14:49 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-26 12:32 [PATCH -v2 0/9] PI and assorted failings Peter Zijlstra
2016-09-26 12:32 ` [PATCH -v2 1/9] rtmutex: Deboost before waking up the top waiter Peter Zijlstra
2016-09-26 15:15 ` Steven Rostedt
2016-09-26 15:22 ` Peter Zijlstra
2016-09-26 15:35 ` Steven Rostedt
2016-09-26 15:37 ` Steven Rostedt
2016-09-26 15:41 ` Peter Zijlstra
2016-09-29 14:43 ` Thomas Gleixner
2016-09-29 14:49 ` Peter Zijlstra [this message]
2016-09-26 15:39 ` Peter Zijlstra
2016-09-28 9:07 ` Sebastian Andrzej Siewior
2016-09-28 9:24 ` Peter Zijlstra
2016-09-26 12:32 ` [PATCH -v2 2/9] sched/rtmutex/deadline: Fix a PI crash for deadline tasks Peter Zijlstra
2016-09-26 15:20 ` Steven Rostedt
2016-09-26 15:26 ` Peter Zijlstra
2016-09-29 14:49 ` Thomas Gleixner
2016-09-26 12:32 ` [PATCH -v2 3/9] sched/deadline/rtmutex: Dont miss the dl_runtime/dl_period update Peter Zijlstra
2016-09-26 16:03 ` Steven Rostedt
2016-09-29 14:48 ` Thomas Gleixner
2016-09-26 12:32 ` [PATCH -v2 4/9] rtmutex: Remove rt_mutex_fastunlock() Peter Zijlstra
2016-09-29 14:47 ` Thomas Gleixner
2016-09-26 12:32 ` [PATCH -v2 5/9] rtmutex: Clean up Peter Zijlstra
2016-09-26 16:09 ` Steven Rostedt
2016-09-29 14:51 ` Thomas Gleixner
2016-09-26 12:32 ` [PATCH -v2 6/9] sched/rtmutex: Refactor rt_mutex_setprio() Peter Zijlstra
2016-09-26 16:57 ` Steven Rostedt
2016-09-26 12:32 ` [PATCH -v2 7/9] sched,tracing: Update trace_sched_pi_setprio() Peter Zijlstra
2016-09-26 17:04 ` Steven Rostedt
2016-09-27 7:44 ` Peter Zijlstra
2016-09-26 12:32 ` [PATCH -v2 8/9] rtmutex: Fix PI chain order integrity Peter Zijlstra
2016-09-26 12:32 ` [PATCH -v2 9/9] rtmutex: Fix more prio comparisons Peter Zijlstra
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