On Wed, Feb 13, 2019 at 05:52:27PM +0100, Sebastian Andrzej Siewior wrote: > On 2019-02-13 16:40:00 [+0100], Ard Biesheuvel wrote: > > > > This is equal what x86 is currently doing. The naming is slightly > > > > different, there is irq_fpu_usable(). > > > > > > Yes, I think it's basically the same idea. > > > > > > It's been evolving a bit on both sides, but is quite similar now. > > > > > > > may_use_simd() only exists because we have a generic crypto SIMD > > helper, and so we needed something arch agnostic to wrap around > > irq_fpu_usable() > > My question was more if this is helpful and we want to keep or if > it would be better to remove it and always disable BH as part of SIMD > operations. Wouldn't this arbitrarily increase softirq latency? Unconditionally forbidding SIMD in softirq might make more sense. It depends on how important the use cases are... Cheers ---Dave
