On Fri, May 1, 2020 at 12:07 PM Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > > On Thu, Apr 30, 2020 at 04:10:16PM -0600, Jason A. Donenfeld wrote: > > Sometimes it's not okay to use SIMD registers, the conditions for which > > have changed subtly from kernel release to kernel release. Usually the > > pattern is to check for may_use_simd() and then fallback to using > > something slower in the unlikely case SIMD registers aren't available. > > So, this patch fixes up i915's accelerated memcpy routines to fallback > > to boring memcpy if may_use_simd() is false. > > Err, why does i915 implements its own uncached memcpy instead of relying > on core functionality to start with? I was wondering the same. It sure does seem like this ought to be more generalized functionality, with a name that represents the type of transfer it's optimized for (wc or similar).
