Re: [PATCH RFC 0/3] x86: Full support of PAT

2014-08-20 Thread H. Peter Anvin
On 08/20/2014 07:05 AM, One Thousand Gnomes wrote: > Doing this stuff for Xen also IMHO makes no sense at all. We shouldn't > have a kernel full of crap to deal with Xen-isms. We already *have* a kernel full of crap to deal with Xen-isms. We screwed that pooch some 10 years ago. > IFF it means t

Re: [PATCH RFC 0/3] x86: Full support of PAT

2014-08-20 Thread Juergen Gross
On 08/20/2014 02:05 PM, One Thousand Gnomes wrote: The Linux kernel currently supports only 4 different cache modes. The PAT MSR is set up in a way that the setting of _PAGE_PAT in a pte doesn't matter: the top 4 entries in the PAT MSR are the same as the 4 lower entries. This results in the ker

Re: [PATCH RFC 0/3] x86: Full support of PAT

2014-08-20 Thread One Thousand Gnomes
> The Linux kernel currently supports only 4 different cache modes. The PAT MSR > is set up in a way that the setting of _PAGE_PAT in a pte doesn't matter: the > top 4 entries in the PAT MSR are the same as the 4 lower entries. > > This results in the kernel not supporting e.g. write-through mode.