Messages in this thread | | | Subject | Re: [PATCH v8 4/8] mm,memory_hotplug: Allocate memmap from the added memory range | From | David Hildenbrand <> | Date | Fri, 16 Apr 2021 12:51:31 +0200 |
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On 16.04.21 12:37, Oscar Salvador wrote: > On Fri, Apr 16, 2021 at 12:33:34PM +0200, David Hildenbrand wrote: >> IIRC, we have to add the zero shadow first, before touching the memory. This >> is also what mm/memremap.c does. >> >> In mhp_deinit_memmap_on_memory(), you already remove in the proper >> (reversed) order :) > > But looking at online_pages(), we do it after the > move_pfn_range_to_zone(), right? AFAIK (I might be well wrong here), > memory_notify() will eventually call kasan_add_zero_shadow? So that > comes after the move_pfn_range_to_zone? Or is my understanding > incorrect?
The thing is: move_pfn_range_to_zone() in case of ordinary online_pages() won't touch the pages but only the memmap. The memmap has a proper kasan shadow already. Pages won't be touched before exposing them to the page allocator via generic_online_pages().
This is different in this case :)
-- Thanks,
David / dhildenb
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