Re: [PATCH v8 3/3] x86, mce: Add __mcsafe_copy()
On Sat, Jan 9, 2016 at 11:39 AM, Tony Luck <tony.luck(a)gmail.com> wrote:
On Sat, Jan 9, 2016 at 9:57 AM, Andy Lutomirski
<luto(a)amacapital.net> wrote:
> On Sat, Jan 9, 2016 at 9:48 AM, Tony Luck <tony.luck(a)gmail.com> wrote:
>> ERMS?
>
> It's the fast string extension, aka Enhanced REP MOV STOS. On CPUs
> with that feature (and not disabled via MSR), plain ol' rep movs is
> the fastest way to copy bytes. I think this includes all Intel CPUs
> from SNB onwards.
Ah ... very fast at copying .. but currently not machine check recoverable.
Hmm, I assume for the pmem driver I'll want to check at runtime if the
cpu has machine check recovery and fall back to the faster copy if
it's not available?