Re: [PATCH v9 2/3] x86/mce: Add per-bank CMCI storm mitigation

[Yazen Ghannam]

On 11/27/2023 7:42 PM, Tony Luck wrote:
> On Mon, Nov 27, 2023 at 12:14:28PM -0800, Tony Luck wrote:
> > On Mon, Nov 27, 2023 at 11:50:26AM -0800, Tony Luck wrote:
> > > On Tue, Nov 21, 2023 at 12:54:48PM +0100, Borislav Petkov wrote:
> > > > On Tue, Nov 14, 2023 at 02:04:46PM -0800, Tony Luck wrote:
> > > But it isn't doing the same thing.  The timer calls:
> > >
> > > 	machine_check_poll(0, this_cpu_ptr(&mce_poll_banks));
> > >
> > > and cmci_mc_poll_banks() calls:
> > >
> > > 	machine_check_poll(0, this_cpu_ptr(&mce_poll_banks));
>
>          machine_check_poll(0, this_cpu_ptr(&mce_banks_owned));
>
> > Bah ... I've cut & pasted the same thing ... but I think there
> > are separate bit maps ... maybe I'm wrong. Will go back and
> > look again.

This mutually exclusive behavior is not enforced on AMD systems. A bank 
can be polled and signaled using hardware interrupts.

I've been thinking to change this in order to save polling cycles. Now 
it seems there's another reason. :)

Thanks,
Yazen