Re: [PATCH 2/3] x86/cpufeatures: Add WBNOINVD cpufeature

From: Thomas Gleixner
Date: Thu Mar 15 2018 - 05:17:29 EST


On Fri, 19 Jan 2018, Kirill A. Shutemov wrote:

> CPUID.0x80000008:EBX[9] indicates whether CPU supports WBNOINVD
> instruction.
>
> The WBNOINVD instruction writes back all modified cache lines in the
> processorâs internal cache to main memory and does not invalidate
> (flush) the internal caches.

That's describing what that instruction does. Could you please explain why
this is useful and what kind of usage you envision for that.

Thanks,

tglx