David Hildenbrand b3d40a2b6d mm: enforce pageblock_order < MAX_ORDER ... Some places in the kernel don't really expect pageblock_order >= MAX_ORDER, and it looks like this is only possible in corner cases: 1) CONFIG_DEFERRED_STRUCT_PAGE_INIT we'll end up freeing pageblock_order pages via __free_pages_core(), which cannot possibly work. 2) find_zone_movable_pfns_for_nodes() will roundup the ZONE_MOVABLE start PFN to MAX_ORDER_NR_PAGES. Consequently with a bigger pageblock_order, we could have a single pageblock partially managed by two zones. 3) compaction code runs into __fragmentation_index() with order >= MAX_ORDER, when checking WARN_ON_ONCE(order >= MAX_ORDER). [1] 4) mm/page_reporting.c won't be reporting any pages with default page_reporting_order == pageblock_order, as we'll be skipping the reporting loop inside page_reporting_process_zone(). 5) __rmqueue_fallback() will never be able to steal with ALLOC_NOFRAGMENT. pageblock_order >= MAX_ORDER is weird either way: it's a pure optimization for making alloc_contig_range(), as used for allcoation of gigantic pages, a little more reliable to succeed. However, if there is demand for somewhat reliable allocation of gigantic pages, affected setups should be using CMA or boottime allocations instead. So let's make sure that pageblock_order < MAX_ORDER and simplify. [1] https://lkml.kernel.org/r/87r189a2ks.fsf@linux.ibm.com Link: https://lkml.kernel.org/r/20220214174132.219303-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Frank Rowand <frowand.list@gmail.com> Cc: John Garry via iommu <iommu@lists.linux-foundation.org> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Rob Herring <robh+dt@kernel.org> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2022-03-22 15:57:06 -07:00
..
Kconfig	virtio: drop default for virtio-mem	2022-03-06 06:06:50 -05:00
Makefile	virtio-pci: introduce legacy device module	2021-11-01 04:30:34 -04:00
virtio_balloon.c	virtio: wrap config->reset calls	2022-01-14 18:50:52 -05:00
virtio_dma_buf.c	dma-buf: move dma-buf symbols into the DMA_BUF module namespace	2021-10-25 14:53:08 +02:00
virtio_input.c	virtio: wrap config->reset calls	2022-01-14 18:50:52 -05:00
virtio_mem.c	mm: enforce pageblock_order < MAX_ORDER	2022-03-22 15:57:06 -07:00
virtio_mmio.c	virtio-mmio: Use to_virtio_mmio_device() to simply code	2021-03-14 04:37:35 -04:00
virtio_pci_common.c	virtio-pci: harden INTX interrupts	2021-11-01 05:26:48 -04:00
virtio_pci_common.h	virtio-pci: harden INTX interrupts	2021-11-01 05:26:48 -04:00
virtio_pci_legacy_dev.c	virtio/virtio_pci_legacy_dev: ensure the correct return value	2022-01-14 18:50:53 -05:00
virtio_pci_legacy.c	virtio-pci: fix the confusing error message	2022-01-14 18:50:53 -05:00
virtio_pci_modern_dev.c	virtio: fix a typo in function "vp_modern_remove" comments.	2022-01-14 18:50:53 -05:00
virtio_pci_modern.c	virtio_pci: harden MSI-X interrupts	2021-11-01 05:26:48 -04:00
virtio_ring.c	virtio_ring: mark ring unused on error	2022-01-14 18:50:53 -05:00
virtio_vdpa.c	vdpa: factor out vdpa_set_features_unlocked for vdpa internal use	2022-03-04 11:56:33 -05:00
virtio.c	virtio: document virtio_reset_device	2022-03-04 08:33:22 -05:00