Hi!
This is due to the commit 9f1eb38e0e11 ("mm, kmemleak: little optimization while scanning") starts to use pfn_to_online_page() instead of pfn_valid(). However, in the CONFIG_MEMORY_HOTPLUG=y case, pfn_to_online_page() does not call memblock_is_map_memory() while pfn_valid() does.
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Fixes: 9f1eb38e0e11 ("mm, kmemleak: little optimization while scanning")
Commit 9f1eb38e0e11 does not seem to be in v4.19-stable tree. Is this commit still neccessary/good idea?
Best regards, Pavel