On Thu, Feb 06, 2020 at 07:19:45AM +0800, Wei Yang wrote: >On Wed, Feb 05, 2020 at 02:52:51PM +0100, David Hildenbrand wrote: >>Let's use a calculation that's easier to understand and calculates the >>same result. Reusing existing macros makes this look nicer. >> >>We always want to have the number of pages (> 0) to the next section >>boundary, starting from the current pfn. >> >>Suggested-by: Segher Boessenkool <segher@xxxxxxxxxxxxxxxxxxx> >>Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> >>Cc: Michal Hocko <mhocko@xxxxxxxxxx> >>Cc: Oscar Salvador <osalvador@xxxxxxx> >>Cc: Baoquan He <bhe@xxxxxxxxxx> >>Cc: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx> >>Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> > >Reviewed-by: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx> > >BTW, I got one question about hotplug size requirement. > >I thought the hotplug range should be section size aligned, while taking a >look into current code function check_hotplug_memory_range() guard the range. > >This function says the range should be block_size aligned. And if I am >correct, block size on x86 should be in the range > > [MIN_MEMORY_BLOCK_SIZE, MEM_SIZE_FOR_LARGE_BLOCK] > >And MIN_MEMORY_BLOCK_SIZE is section size. > >Seems currently we support subsection hotplug? Then how a subsection range got >hotplug? Or this patch is a pre-requisite? > One more question is we support hot-add subsection memory but not support hot-online subsection memory. Is my understanding correct? -- Wei Yang Help you, Help me
