Messages in this thread | | | Date | Sun, 26 Aug 2018 16:06:32 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH v2 01/17] asm: simd context helper API |
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Jason,
On Sun, 26 Aug 2018, Jason A. Donenfeld wrote: > On Sun, Aug 26, 2018 at 6:10 AM Thomas Gleixner <tglx@linutronix.de> 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
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