Re: [PATCH] mm/memtest: Add ARCH_USE_MEMTEST

On 2/5/21 2:50 PM, Vladimir Murzin wrote:

Hi Anshuman,

On 2/5/21 4:10 AM, Anshuman Khandual wrote:

quoted

early_memtest() does not get called from all architectures. Hence enabling
CONFIG_MEMTEST and providing a valid memtest=[1..N] kernel command line
option might not trigger the memory pattern tests as would be expected in
normal circumstances. This situation is misleading.

Documentation already mentions which architectures support that:

memtest=        [KNL,X86,ARM,PPC] Enable memtest

yet I admit that not all reflected there

But there is nothing that prevents CONFIG_MEMTEST from being set on
other platforms that do not have an affect, which is not optimal.

quoted

The change here prevents the above mentioned problem after introducing a
new config option ARCH_USE_MEMTEST that should be subscribed on platforms
that call early_memtest(), in order to enable the config CONFIG_MEMTEST.
Conversely CONFIG_MEMTEST cannot be enabled on platforms where it would
not be tested anyway.

Is that generic pattern? What about other cross arch parameters? Do they already
use similar subscription or they rely on documentation?

Depending solely on the documentation should not be sufficient.

I'm not against the patch just want to check if things are consistent...

Not sure about other similar situations but those if present should
get fixed as well.