> On 5 Oct 2018, at 20:28, Jason A. Donenfeld <Jason@xxxxxxxxx> wrote: > > Hey Andy, > >> On Fri, Oct 5, 2018 at 7:44 PM Andy Lutomirski <luto@xxxxxxxxxx> wrote: >> I *think* the only change to Zinc per se would be that the calls like >> chacha20_simd() would be static calls or patchable functions or >> whatever we want to call them. And there could be a debugfs to >> override the default selection. > > Yea, right, exactly. It turns out this is really easy to do with the > way it's structured now. I'd actually experimented considerably with > using the static keys a while back, but couldn't find any performance > difference on any platform at all (four ARM microarchitectures, three > MIPS, various random intel, an old powerpc), so went with the simplest > solution. But we can certainly play with more elaborate patching > mechanisms later on and see how those turn out. Also, even with the > simple bools as we have now, it's quite easy to make all the > parameters toggle-able. > >> Ard, I don't think that sticking this in udev rules makes sense. The >> kernel has bascially complete information as to what the right choice >> is, and that will change over time as the implementation gets tuned, >> and the udev rules will never get updated in sync. > > Yes, I agree with this. > > I am not referring to udev rules. I just mean the current way that udev autoloads modules based on CPU features.
