On 09.12.20 11:02, Oscar Salvador wrote: > On Wed, Dec 02, 2020 at 10:42:18AM +0100, David Hildenbrand wrote: >> I have another memhp tunable in the works. I suggest doing it like >> page_shuffling and using, module parameters instead. Makes this >> a bit nicer IMHO. > > Does that have any impact? Not that I am aware of for our use case. You can inspect parameters via /sys/modules/memory_hotplug/parameters/ then, and even change them (if allowed for a specific module parameters) > >> diff --git a/mm/Makefile b/mm/Makefile >> index 069f216e109e..ba7714b5eaa1 100644 >> --- a/mm/Makefile >> +++ b/mm/Makefile >> @@ -58,9 +58,13 @@ obj-y := filemap.o mempool.o oom_kill.o fadvise.o \ >> page-alloc-y := page_alloc.o >> page-alloc-$(CONFIG_SHUFFLE_PAGE_ALLOCATOR) += shuffle.o >> >> +# Give "memory_hotplug" its own module-parameter namespace >> +memory-hotplug-$(CONFIG_MEMORY_HOTPLUG) := memory_hotplug.o >> + >> obj-y += page-alloc.o >> obj-y += init-mm.o >> obj-y += memblock.o >> +obj-y += $(memory-hotplug-y) >> >> ifdef CONFIG_MMU >> obj-$(CONFIG_ADVISE_SYSCALLS) += madvise.o >> @@ -82,7 +86,6 @@ obj-$(CONFIG_SLAB) += slab.o >> obj-$(CONFIG_SLUB) += slub.o >> obj-$(CONFIG_KASAN) += kasan/ >> obj-$(CONFIG_FAILSLAB) += failslab.o >> -obj-$(CONFIG_MEMORY_HOTPLUG) += memory_hotplug.o >> obj-$(CONFIG_MEMTEST) += memtest.o >> obj-$(CONFIG_MIGRATION) += migrate.o >> obj-$(CONFIG_TRANSPARENT_HUGEPAGE) += huge_memory.o khugepaged.o >> >> >> The you can just use module_param/MODULE_PARM_DESC and set the parameter via >> >> "memory_hotplug.memmap_on_memory" > > I have to confess that I was not aware of this trick, but looks cleaner > overall. Me neither before I spotted the page_alloc page_shuffling usage :) -- Thanks, David / dhildenb
