Re: [PATCH 3/6] x86-mce: Clear CMCI enable on all claimed CMCI banks before reboot.

[Havard Skinnemoen]

On Wed, Jul 9, 2014 at 1:36 PM, Luck, Tony <tony.luck@xxxxxxxxx> wrote:
> +       if (!xchg(&reboot_notifier_registered, true))
> +               register_reboot_notifier(&cmci_reboot_notifier);
>
> This is super-safe ... but isn't the xchg() overkill? I thought we serialized bringup
> of other cpus.

Could be. There are spinlocks being taken elsewhere in that path
though, and I'm not sure if I see any downside with the xchg(), unless
this path is actually performance-critical.

Havard
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/