On 03/04/2019 09:20, David Hildenbrand wrote:
On 03.04.19 06:30, Anshuman Khandual wrote:
Sysfs memory probe interface (/sys/devices/system/memory/probe) can accept
starting physical address of an entire memory block to be hot added into
the kernel. This is in addition to the existing ACPI based interface. This
just enables it with the required config CONFIG_ARCH_MEMORY_PROBE.
We recently discussed that the similar interface for removal should
rather be moved to a debug/test module
I wonder if we should try to do the same for the sysfs probing
interface. Rather try to get rid of it than open the doors for more users.
Agreed - if this option even exists in a released kernel, there's a risk
that distros will turn it on for the sake of it, and at that point arm64
is stuck carrying the same ABI baggage as well.
If users turn up in future with a desperate and unavoidable need for the
legacy half-an-API on arm64, we can always reconsider adding it at that
point. It was very much deliberate that my original hot-add support did
not include a patch like this one.
Robin.
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
---
arch/arm64/Kconfig | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 7e34b9e..a2418fb 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -266,6 +266,15 @@ config HAVE_GENERIC_GUP
config ARCH_ENABLE_MEMORY_HOTPLUG
def_bool y
+config ARCH_MEMORY_PROBE
+ bool "Enable /sys/devices/system/memory/probe interface"
+ depends on MEMORY_HOTPLUG
+ help
+ This option enables a sysfs /sys/devices/system/memory/probe
+ interface for testing. See Documentation/memory-hotplug.txt
+ for more information. If you are unsure how to answer this
+ question, answer N.
+
config SMP
def_bool y
