> >> any idea how to find out what that might be? I'd really have no idea, > >> I also wonder why this never was an issue with 3.x > >> find uses regex patterns, that's the only thing that may be unusual. > > > > The allocation tracepoint has the stack trace so that might help. This > > Well we already checked the mm_page_alloc traces and it seemed that only > THP allocations could be the culprit. But apparently defrag=defer made > no difference. I would still recommend it so we can see the effects on > the traces. And adding tracepoints > compaction/mm_compaction_try_to_compact_pages and > compaction/mm_compaction_suitable as I suggested should show which > high-order allocations actually invoke the compaction. Anything in particular I should do to figure this out?
