| From | Andy Lutomirski <> | Date | Fri, 13 Jul 2018 11:59:44 -0700 | Subject | Re: [PATCH 38/39] x86/mm/pti: Add Warning when booting on a PCID capable CPU |
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On Wed, Jul 11, 2018 at 4:29 AM, Joerg Roedel <joro@8bytes.org> wrote: > From: Joerg Roedel <jroedel@suse.de> > > Warn the user in case the performance can be significantly > improved by switching to a 64-bit kernel.
...
> +#ifdef CONFIG_X86_32 > + if (boot_cpu_has(X86_FEATURE_PCID)) {
I'm a bit confused. Wouldn't the setup_clear_cpu_cap() call in early_identify_cpu() prevent this from working?
Boris, do we have a straightforward way to ask "does the CPU advertise this feature in CPUID regardless of whether we have it enabled right now"?
--Andy
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