On Mon, 30 Oct 2023, Vlastimil Babka wrote: > Ah, missed that. And the traces don't show that we would be waiting for > that. I'm starting to think the allocation itself is really not the issue > here. Also I don't think it deprives something else of large order pages, as > per the sysrq listing they still existed. > > What I rather suspect is what happens next to the allocated bio such that it > works well with order-0 or up to costly_order pages, but there's some > problem causing a deadlock if the bio contains larger pages than that? Yes. There are many "if (order > PAGE_ALLOC_COSTLY_ORDER)" branches in the memory allocation code and I suppose that one of them does something bad and triggers this bug. But I don't know which one. > Cc Honza. The thread starts here: > https://lore.kernel.org/all/ZTNH0qtmint%2FzLJZ@mail-itl/ > > The linked qubes reports has a number of blocked task listings that can be > expanded: > https://github.com/QubesOS/qubes-issues/issues/8575 Mikulas
