On Mon, 15 Jan 2018, Laurent Dufour wrote:

On 12/01/2018 19:57, Thomas Gleixner wrote:

quoted

On Fri, 12 Jan 2018, Laurent Dufour wrote:

quoted

Introduce CONFIG_SPF which turns on the Speculative Page Fault handler when
building for 64bits with SMP.

Signed-off-by: Laurent Dufour <redacted>
---
 arch/x86/Kconfig | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index a317d5594b6a..d74353b85aaf 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig

@@ -2882,6 +2882,10 @@ config X86_DMA_REMAP
 config HAVE_GENERIC_GUP
 	def_bool y
 
+config SPF
+	def_bool y
+	depends on X86_64 && SMP

Can you please put that into a generic place as

    config SPF
    	   bool

and let the architectures select it.

I'll change that to let the architectures (x86 and ppc64 currently)
selecting it, but the definition will remain in the arch/xxx/Kconfig file
since it depends on the architecture support in the page fault handler.

Errm. No.

	config SPECULATIVE_PAGE_FAULT
      		bool

goes into a generic config file, e.g. mm/Kconfig

Each architecture which implements support does:

	select SPECULATIVE_PAGE_FAULT

in arch/xxx/Kconfig

Thanks,

	tglx