Re: LTTng "TIF_KERNEL_TRACE"

Frederic Weisbecker
2009-04-28T16:44:35Z

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
>