Hi Geert, > > --- a/arch/m68k/Kconfig > > +++ b/arch/m68k/Kconfig > > @@ -20,7 +20,6 @@ config M68K > > select GENERIC_STRNLEN_USER if MMU > > select ARCH_WANT_IPC_PARSE_VERSION > > select ARCH_USES_GETTIMEOFFSET if MMU && !COLDFIRE > > - select HAVE_FUTEX_CMPXCHG if MMU && FUTEX > > I guess it didn't really matter for !MMU?
I see that m68k uses generic futex.h, which doesn't depend on MMU vs noMMU. > > --- a/include/asm-generic/futex.h > > +++ b/include/asm-generic/futex.h > > @@ -136,6 +136,8 @@ arch_futex_atomic_op_inuser(int op, u32 oparg, int > > *oval, u32 __user *uaddr) > > return ret; > > } > > > > +#define arch_have_futex_cmpxchg() (0) > > This is for the SMP=y case only, right? Yes, that's where generic implementation always returns -ENOSYS > > --- a/kernel/futex.c > > +++ b/kernel/futex.c > > @@ -174,7 +174,11 @@ > > * double_lock_hb() and double_unlock_hb(), respectively. > > */ > > > > -#ifdef CONFIG_HAVE_FUTEX_CMPXCHG > > +/* > > + * Architectures should define this macro if > > futex_atomic_cmpxchg_inatomic() > > + * may not be always working. > > + */ > > +#ifdef arch_have_futex_cmpxchg > > Shouldn't this be #ifndef now... Oops, thank you. I thought I've build-tested both cases, but I obviously haven't... > > @@ -3880,7 +3864,9 @@ static int __init futex_init(void) > > futex_hashsize, > > futex_hashsize); > > futex_hashsize = 1UL << futex_shift; > > > > - futex_detect_cmpxchg(); > > +#ifdef arch_have_futex_cmpxchg > > + futex_cmpxchg_enabled = arch_have_futex_cmpxchg(); > > ... else you're assigning to the constant: > > error: lvalue required as left operand of assignment Will send v2... -- Thanks. -- Max
