On 9/22/22 08:53, Rafael J. Wysocki wrote: > On Thu, Sep 22, 2022 at 5:36 PM Borislav Petkov <bp@xxxxxxxxx> wrote: >> On Thu, Sep 22, 2022 at 05:21:21PM +0200, Rafael J. Wysocki wrote: >>> Well, it can be forced to use ACPI idle instead. >> Yeah, I did that earlier. The dummy IO read in question costs ~3K on >> average on my Coffeelake box here. > Well, that's the cost of forcing something non-default. Just to be clear: The _original_ AMD Zen problem that this thread is addressing is from a *default* configuration, right? It isn't that someone overrode the idle defaults?