Re: [PATCH v2 01/17] asm: simd context helper API
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: 2018-08-26 13:45:27
Also in:
linux-arch, lkml
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: 2018-08-26 13:45:27
Also in:
linux-arch, lkml
Hey Thomas, On Sun, Aug 26, 2018 at 6:10 AM Thomas Gleixner [off-list ref] 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? 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. Jason