On 14 Sep. 2016 10:12 pm, "Nicholas Piggin" <npig...@gmail.com> wrote: > > On Wed, 14 Sep 2016 21:46:39 +1000 > Michael Neuling <mi...@neuling.org> wrote: > > > On Wed, 2016-09-14 at 21:28 +1000, Nicholas Piggin wrote: > > > Cc'ing Carlos > > > > > > On Wed, 14 Sep 2016 18:02:14 +1000
> > I think we might be able to detect this case in the kernel. If it's a tabort > > that's trapped on, we can't have been transactional. Hence we can safely PC+=4 > > and leave off TM off. > > > > It would cost us a get_user(inst, regs->nip); but it might be worth it for this > > special but common case. > > That would take an extra trap for every syscall, I think. You're right. That wouldn't work. Mikey
