[RFC,1/5] powerpc: Don't do runtime futex_cmpxchg test

Message ID 20180210105643.11857-2-aneesh.kumar@linux.vnet.ibm.com
State Superseded
Headers show
Series
  • Add support for 4PB virtual address space on hash
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Commit Message

Aneesh Kumar K.V Feb. 10, 2018, 10:56 a.m.
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

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 arch/powerpc/platforms/Kconfig.cputype | 1 +
 1 file changed, 1 insertion(+)

Patch

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"