touch_nmi_watchdog (was: page fault scalability patch V11 [0/7]:

Nick Piggin
2004-11-20T07:45:18Z

Nick Piggin wrote:

>> (2) NMI's don't nest. There is no possibility of NMI's racing against
>> themselves while the data is per-cpu.
>>
>
> Your point was that touch_nmi_watchdog() which resets alert_counter,
> is racy when resetting the counter of other CPUs. Yes it is racy.
> It is also racy against the NMI on the _current_ CPU.

Hmm no I think you're right in that it is only a problem WRT the remote
CPUs. However that would still be a problem, as the comment in i386
touch_nmi_watchdog attests.