Guardian Digital Inc. >
Mailing List Archives >
Linux Kernel Mailing List Archive
* Linus Torvalds <email@example.com> wrote:
> > find the correct patch below. I've tested it with an NMI watchdog
> > frequency artificially increased to 10 KHz, and i've instrumented the
> > new branch in the NMI handler, but even under heavy IRQ load i was not
> > able to trigger the branch. Maybe newer CPUs handle this case somehow
> > and make sti;hlt truly atomic?
> Now that you mention it, I have this dim memory of the one-instruction
> "sti-shadow" actually disabling NMI's (and debug traps) too. The CPU
> literally doesn't test for async events following "sti".
i ran the stresstest overnight with the 10 KHz NMI, and not a single
time did the new branch trigger, out of hundreds of millions of IRQs and
NMIs. I think this suggests that the race doesnt exist in current CPUs.
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to firstname.lastname@example.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/