On 8/1/23 2:28 PM, Michal Hocko wrote: > On Tue 01-08-23 10:11:16, Aneesh Kumar K.V wrote: >> Allow updating memmap_on_memory mode after the kernel boot. Memory >> hotplug done after the mode update will use the new mmemap_on_memory >> value. > > Well, this is a user space kABI extension and as such you should spend > more words about the usecase. Why we could live with this static and now > need dynamic? >
This enables easy testing of memmap_on_memory feature without a kernel reboot. I also expect people wanting to use that when they find dax kmem memory online failing because of struct page allocation failures[1]. User could reboot back with memmap_on_memory=y kernel parameter. But being able to enable it via sysfs makes the feature much more useful. -aneesh
