From: Steven Rostedt <rostedt@goodmis.org>
To: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
linux-kernel@vger.kernel.org,
linux-rt-users <linux-rt-users@vger.kernel.org>,
Carsten Emde <C.Emde@osadl.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
John Kacur <jkacur@redhat.com>,
Paul Gortmaker <paul.gortmaker@windriver.com>,
Peter Zijlstra <peterz@infradead.org>,
Clark Williams <clark.williams@gmail.com>,
Arnaldo Carvalho de Melo <acme@redhat.com>
Subject: Re: [RFC][PATCH RT 0/3] RT: Fix trylock deadlock without msleep() hack
Date: Sat, 5 Sep 2015 08:26:26 -0400 [thread overview]
Message-ID: <20150905082626.00a20902@gandalf.local.home> (raw)
In-Reply-To: <20150905120457.GA21338@gmail.com>
On Sat, 5 Sep 2015 14:04:57 +0200
Ingo Molnar <mingo@kernel.org> wrote:
> So why not do:
>
> lock(B);
> if (!trylock(A)) {
> unlock(B);
> lock(A);
> lock(B);
> }
>
> ?
>
> Or, if this can be done, why didn't we do:
>
> lock(A);
> lock(B);
>
> to begin with?
>
> i.e. I'm not sure the problem is properly specified.
Yeah, this is actually the solution I came up with before. I misread
what Thomas wrote. His is slightly different.
-- Steve
next prev parent reply other threads:[~2015-09-05 12:26 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-04 1:19 [RFC][PATCH RT 0/3] RT: Fix trylock deadlock without msleep() hack Steven Rostedt
2015-09-04 1:19 ` [RFC][PATCH RT 1/3] locking: Add spin_try_or_boost_lock() infrastructure Steven Rostedt
2015-09-04 1:48 ` Steven Rostedt
2015-09-04 1:19 ` [RFC][PATCH RT 2/3] locking: Convert trylock spinners over to spin_try_or_boost_lock() Steven Rostedt
2015-09-04 1:19 ` [RFC][PATCH RT 3/3] rt: Make cpu_chill() into yield() and add new cpu_rest() as msleep(1) Steven Rostedt
2015-09-05 10:30 ` [RFC][PATCH RT 0/3] RT: Fix trylock deadlock without msleep() hack Thomas Gleixner
2015-09-05 12:04 ` Ingo Molnar
2015-09-05 12:26 ` Steven Rostedt [this message]
2015-09-07 8:35 ` Thomas Gleixner
2015-09-07 10:10 ` Thomas Gleixner
2015-09-08 7:31 ` Ingo Molnar
2015-09-08 8:09 ` Thomas Gleixner
2015-09-14 9:50 ` Ingo Molnar
2015-09-08 16:59 ` Steven Rostedt
2015-09-08 19:35 ` Steven Rostedt
2015-09-05 12:18 ` Steven Rostedt
2015-09-05 12:27 ` Steven Rostedt
2015-09-05 12:50 ` Steven Rostedt
2015-09-07 9:14 ` Thomas Gleixner
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