The patch titled Subject: mm/page_alloc: correct return value of populated elements if bulk array is populated has been added to the -mm tree. Its filename is mm-page_alloc-correct-return-value-of-populated-elements-if-bulk-array-is-populated.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-page_alloc-correct-return-value-of-populated-elements-if-bulk-array-is-populated.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-page_alloc-correct-return-value-of-populated-elements-if-bulk-array-is-populated.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Subject: mm/page_alloc: correct return value of populated elements if bulk array is populated Dave Jones reported the following This made it into 5.13 final, and completely breaks NFSD for me (Serving tcp v3 mounts). Existing mounts on clients hang, as do new mounts from new clients. Rebooting the server back to rc7 everything recovers. The commit b3b64ebd3822 ("mm/page_alloc: do bulk array bounds check after checking populated elements") returns the wrong value if the array is already populated which is interpreted as an allocation failure. Dave reported this fixes his problem and it also passed a test running dbench over NFS. Link: https://lkml.kernel.org/r/20210628150219.GC3840@xxxxxxxxxxxxxxxxxxx Fixes: b3b64ebd3822 ("mm/page_alloc: do bulk array bounds check after checking populated elements") Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Reported-by: Dave Jones <davej@xxxxxxxxxxxxxxxxx> Tested-by: Dave Jones <davej@xxxxxxxxxxxxxxxxx> Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Cc: Jesper Dangaard Brouer <brouer@xxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> [5.13+] Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/page_alloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/page_alloc.c~mm-page_alloc-correct-return-value-of-populated-elements-if-bulk-array-is-populated +++ a/mm/page_alloc.c @@ -5058,7 +5058,7 @@ unsigned long __alloc_pages_bulk(gfp_t g /* Already populated array? */ if (unlikely(page_array && nr_pages - nr_populated == 0)) - return 0; + return nr_populated; /* Use the single page allocator for one page. */ if (nr_pages - nr_populated == 1) _ Patches currently in -mm which might be from mgorman@xxxxxxxxxxxxxxxxxxx are mm-page_alloc-correct-return-value-of-populated-elements-if-bulk-array-is-populated.patch mm-page_alloc-split-per-cpu-page-lists-and-zone-stats.patch mm-page_alloc-split-per-cpu-page-lists-and-zone-stats-fix.patch mm-page_alloc-split-per-cpu-page-lists-and-zone-stats-fix-fix.patch mm-page_alloc-convert-per-cpu-list-protection-to-local_lock.patch mm-page_alloc-convert-per-cpu-list-protection-to-local_lock-fix.patch mm-vmstat-convert-numa-statistics-to-basic-numa-counters.patch mm-vmstat-inline-numa-event-counter-updates.patch mm-page_alloc-batch-the-accounting-updates-in-the-bulk-allocator.patch mm-page_alloc-reduce-duration-that-irqs-are-disabled-for-vm-counters.patch mm-page_alloc-explicitly-acquire-the-zone-lock-in-__free_pages_ok.patch mm-page_alloc-avoid-conflating-irqs-disabled-with-zone-lock.patch mm-page_alloc-update-pgfree-outside-the-zone-lock-in-__free_pages_ok.patch mm-page_alloc-delete-vmpercpu_pagelist_fraction.patch mm-page_alloc-disassociate-the-pcp-high-from-pcp-batch.patch mm-page_alloc-disassociate-the-pcp-high-from-pcp-batch-fix-2.patch mm-page_alloc-adjust-pcp-high-after-cpu-hotplug-events.patch mm-page_alloc-scale-the-number-of-pages-that-are-batch-freed.patch mm-page_alloc-limit-the-number-of-pages-on-pcp-lists-when-reclaim-is-active.patch mm-page_alloc-introduce-vmpercpu_pagelist_high_fraction.patch mm-page_alloc-introduce-vmpercpu_pagelist_high_fraction-fix.patch mm-page_alloc-move-free_the_page.patch mm-page_alloc-allow-high-order-pages-to-be-stored-on-the-per-cpu-lists.patch mm-page_alloc-split-pcp-high-across-all-online-cpus-for-cpuless-nodes.patch mm-vmscan-remove-kerneldoc-like-comment-from-isolate_lru_pages.patch mm-vmalloc-include-header-for-prototype-of-set_iounmap_nonlazy.patch mm-page_alloc-make-should_fail_alloc_page-a-static-function-should_fail_alloc_page-static.patch mm-mapping_dirty_helpers-remove-double-note-in-kerneldoc.patch mm-memcontrolc-fix-kerneldoc-comment-for-mem_cgroup_calculate_protection.patch mm-memory_hotplug-fix-kerneldoc-comment-for-__try_online_node.patch mm-memory_hotplug-fix-kerneldoc-comment-for-__remove_memory.patch mm-zbud-add-kerneldoc-fields-for-zbud_pool.patch mm-z3fold-add-kerneldoc-fields-for-z3fold_pool.patch mm-swap-make-swap_address_space-an-inline-function.patch mm-mmap_lock-remove-dead-code-for-config_tracing-configurations.patch mm-page_alloc-move-prototype-for-find_suitable_fallback.patch mm-swap-make-node_data-an-inline-function-on-config_flatmem.patch