Hi Arnd, On Tue, Dec 15, 2020 at 7:26 PM Arnd Bergmann <arnd@xxxxxxxxxx> wrote: > > On Tue, Dec 15, 2020 at 7:09 AM Guo Ren <guoren@xxxxxxxxxx> wrote: > > On Mon, Dec 14, 2020 at 9:15 PM Arnd Bergmann <arnd@xxxxxxxxxx> wrote: > > > I had a look at what other architectures always implement > > > futex_atomic_cmpxchg_inatomic() or can use the asm-generic non-SMP version, > > > and I found that it's pretty much all of them, the odd ones being just sparc32 > > > and csky, which use asm-generic/futex.h but do have an SMP option, > > > as well as xtensa > > > > > > I would guess that for csky, this is a mistake, as the architecture is fairly > > > new and should be able to implement it. Not sure about sparc32. > > > > The c610, c807, c810 don't support SMP, so futex_cmpxchg_enabled = 1 > > with asm-generic's implementation. > > For c860, there is no HAVE_FUTEX_CMPXCHG and cmpxchg_inatomic/inuser > > implementation, so futex_cmpxchg_enabled = 0. > > > > Thx for point it out, we'll implement cmpxchg_inatomic/inuser for C860 > > and still use asm-generic for non-smp CPUs. > > Sounds good to me. Done: https://lore.kernel.org/linux-csky/1608478763-60148-3-git-send-email-guoren@xxxxxxxxxx/T/#u -- Best Regards Guo Ren ML: https://lore.kernel.org/linux-csky/
