Re: Backports that remove FPU lazy-mode deadcode for 4.9.y

On Thu, Jul 12, 2018 at 09:16:33AM +0900, Daniel Sangorrin wrote:

Hello Greg,

Please consider this backport for 4.9.y. It completes the removal of FPU lazy-mode code, documentation and comments.

[PATCH v3 4.9] x86/fpu: Remove use_eager_fpu()

After applying the patch, please do the following:

• cherry-pick: 3913cc350757 ("x86/fpu: Remove struct fpu::counter")
• revert: f09a7b0eead7 ("perf: sync up x86/.../cpufeatures.h")
  • Because the modification in this patch actually belongs to e63650840e8b ("x86/fpu: Finish excising 'eagerfpu'")
• cherry-pick: e63650840e8b ("x86/fpu: Finish excising 'eagerfpu'")

That's a major pain.

Tell me again why we are doing this for the stable trees? What does this buy us? It's nice cleanups sure, but are these going to be needed for future backports? Something else?

thanks,

greg k-h