From: Frederic Weisbecker <fweisbec@gmail.com>
To: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Ingo Molnar <mingo@elte.hu>, Steven Rostedt <rostedt@goodmis.org>,
Li Zefan <lizf@cn.fujitsu.com>,
linux-kernel@vger.kernel.org
Subject: Re: LTTng "TIF_KERNEL_TRACE"
Date: Tue, 28 Apr 2009 18:44:21 +0200 [thread overview]
Message-ID: <20090428164420.GA7337@nowhere> (raw)
In-Reply-To: <20090428163825.GA2030@Krystal>
On Tue, Apr 28, 2009 at 12:38:25PM -0400, Mathieu Desnoyers wrote:
> No, read-write lock is a "special case" where it does not deadlock if
> you have an interrupt handler taking the read lock over another read
> lock. It's just the write lock that _must absolutely_ disable
> interrupts.
Ah, you're right, I was thinking with spinlock rules in mind :)
> However, the "latency race" scenario I explained above applies here,
> because the write lock disables interrupts and the read locks doesn't.
>
> Mathieu
>
next prev parent reply other threads:[~2009-04-28 16:44 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-28 13:20 LTTng "TIF_KERNEL_TRACE" Mathieu Desnoyers
2009-04-28 15:01 ` Ingo Molnar
2009-04-28 15:21 ` Mathieu Desnoyers
2009-04-28 15:40 ` Mathieu Desnoyers
2009-04-28 16:33 ` Frederic Weisbecker
2009-04-28 16:37 ` Frédéric Weisbecker
2009-04-28 16:38 ` Mathieu Desnoyers
2009-04-28 16:44 ` Frederic Weisbecker [this message]
2009-04-28 16:52 ` Steven Rostedt
2009-04-28 16:43 ` Steven Rostedt
2009-04-28 16:48 ` Frederic Weisbecker
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