Jason, On Sun, 26 Aug 2018, Jason A. Donenfeld wrote: > On Sun, Aug 26, 2018 at 6:10 AM Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote: > > I'm not too fond of this simply because it requires that relax() step in > > all code pathes. I'd rather make that completely transparent by just > > marking the task as FPU using and let the context switch code deal with it > > in case that it gets preempted. I'll let one of my engineers look into > > that next week. > > Do you mean to say you intend to make kernel_fpu_end() and > kernel_neon_end() only actually do something upon context switch, but > not when it's actually called? So that multiple calls to > kernel_fpu_begin() and kernel_neon_begin() can be made without > penalty? On context switch and exit to user. That allows to keep those code pathes fully preemptible. Still twisting my brain around the details. > If so, that'd be great, and I'd certainly prefer this to the > simd_context_t passing. I consider the simd_get/put/relax API a > stopgap measure until something like that is implemented. I really want to avoid this stopgap^Wducttape thing. Thanks, tglx
