Re: [PATCH 2/3] x86/fpu: Simplify kernel_fpu_begin

[Peter Zijlstra]

On Tue, Jun 04, 2019 at 03:11:38PM +0200, Christoph Hellwig wrote:
> On Tue, Jun 04, 2019 at 01:47:01PM +0200, Peter Zijlstra wrote:
> > > +	if (current->mm && !test_thread_flag(TIF_NEED_FPU_LOAD)) {
> > 
> > Did that want to be: !(current->flags & PF_KTHREAD), instead?
> > 
> > Because I'm thinking that kernel_fpu_begin() on a kthread that has
> > use_mm() employed shouldn't be doing this..
> 
> Well, this is intended to not change semantics.  If we should fix
> this is should be a separate patch before or after this series.

Sure; it's just that I just noticed it. We've recently ran into a
similar issue elsewhere.