Re: A question about prefetchw detection in "x86/asm: Cleanup prefetch primitives"

[Xi Ruoyao]

On Wed, 2023-06-21 at 15:09 +0200, Borislav Petkov wrote:
> On Wed, Jun 21, 2023 at 09:06:51PM +0800, Xi Ruoyao wrote:
> > I think it's not an issue in the kernel itself, but announcing
> > 3dnowprefetch in /proc/cpuinfo for an old Intel CPU w/o real prefetchw
> > implementation seems problematic (to me).
> 
> And this is a problem because?

If a code generator parses /proc/cpuinfo for CPU capabilities, it may
generates a no-op prefetchw instead of prefetcht0 as a fallback.

> 
> Think practically.
> 

-- 
Xi Ruoyao <xry111@xxxxxxxxxxx>
School of Aerospace Science and Technology, Xidian University