WARN_ONCE does not warn once

[Michael Ellerman]

Michal Suchánek <msuchanek at suse.de> writes:
> On Thu, Nov 14, 2019 at 05:46:55PM +0100, Michal Suchánek wrote:
>> Hello,
>> 
>> on powernv with 5.3.8 kernel I get flood of messages on boot.
>> 
>> The messages match WARN_ONCE(1, "opal: OPAL_CONSOLE_FLUSH missing.\n");
>
> Asking around it was pointed out that WARN_ONCE warns up to as many
> times as you have CPUs.

Does it?

> Did not bother counting the messages but it may very well be the case it
> is printed once for each CPU.

The way it's implemented is slightly racy, but I'd be surprised if every
CPU hit that race all at once.

Can you give us the full dmesg?

cheers