Re: LTTng "TIF_KERNEL_TRACE"

Steven Rostedt
2009-04-28T16:52:44Z

On Tue, 28 Apr 2009, Frederic Weisbecker wrote:

> 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 :)
>

The only time you would want to do a read_lock_irqsave is if the
write_lock is taken in irq context. But I do not know of any lock where
that is the case.

-- Steve