On 27 Feb. 2018 00:34, "Aneesh Kumar K.V" <[email protected]> wrote:
futex_detect_cmpxchg() does a cmpxchg_futex_value_locked on a NULL user addr to runtime detect whether architecture implements atomic cmpxchg for futex. POWER do implement the feature and hence we can enable the config instead of depending on runtime detection. We could possible enable this on everything. For now limitted to book3s_64 I think everything implements it? Might as well do it all at once. I wouldn't mind putting in an explicit null dereference test if we take this out. Thanks, Nick Signed-off-by: Aneesh Kumar K.V <[email protected]> --- arch/powerpc/platforms/Kconfig.cputype | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype index a429d859f15d..31bc2bd5dfd1 100644 --- a/arch/powerpc/platforms/Kconfig.cputype +++ b/arch/powerpc/platforms/Kconfig.cputype @@ -75,6 +75,7 @@ config PPC_BOOK3S_64 select ARCH_SUPPORTS_NUMA_BALANCING select IRQ_WORK select HAVE_KERNEL_XZ + select HAVE_FUTEX_CMPXCHG if FUTEX config PPC_BOOK3E_64 bool "Embedded processors" -- 2.14.3
