The patch titled Subject: mm/vmscan: add a comment about MADV_FREE pages check in folio_check_dirty_writeback has been added to the -mm tree. Its filename is mm-vmscan-add-a-comment-about-madv_free-pages-check-in-folio_check_dirty_writeback.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-vmscan-add-a-comment-about-madv_free-pages-check-in-folio_check_dirty_writeback.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-vmscan-add-a-comment-about-madv_free-pages-check-in-folio_check_dirty_writeback.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: Miaohe Lin <linmiaohe@xxxxxxxxxx> Subject: mm/vmscan: add a comment about MADV_FREE pages check in folio_check_dirty_writeback Patch series "A few cleanup and fixup patches for vmscan This series contains a few patches to remove obsolete comment, introduce helper to remove duplicated code and so no. Also we take all base pages of THP into account in rare race condition. More details can be found in the respective changelogs. This patch (of 6): The MADV_FREE pages check in folio_check_dirty_writeback is a bit hard to follow. Add a comment to make the code clear. Link: https://lkml.kernel.org/r/20220425111232.23182-2-linmiaohe@xxxxxxxxxx Suggested-by: Huang, Ying <ying.huang@xxxxxxxxx> Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> Reviewed-by: Oscar Salvador <osalvador@xxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/vmscan.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/mm/vmscan.c~mm-vmscan-add-a-comment-about-madv_free-pages-check-in-folio_check_dirty_writeback +++ a/mm/vmscan.c @@ -1435,7 +1435,10 @@ static void folio_check_dirty_writeback( /* * Anonymous pages are not handled by flushers and must be written - * from reclaim context. Do not stall reclaim based on them + * from reclaim context. Do not stall reclaim based on them. + * MADV_FREE anonymous pages are put into inactive file list too. + * They could be mistakenly treated as file lru. So further anon + * test is needed. */ if (!folio_is_file_lru(folio) || (folio_test_anon(folio) && !folio_test_swapbacked(folio))) { _ Patches currently in -mm which might be from linmiaohe@xxxxxxxxxx are mm-shmem-make-shmem_init-return-void.patch mm-memcg-remove-unneeded-nr_scanned.patch mm-mmapc-use-helper-mlock_future_check.patch mm-mremap-use-helper-mlock_future_check.patch mm-mremap-avoid-unneeded-do_munmap-call.patch mm-memory-failurec-minor-cleanup-for-hwpoisonhandlable.patch mm-memory-failurec-dissolve-truncated-hugetlb-page.patch mm-vmscan-remove-obsolete-comment-in-get_scan_count.patch mm-vmscan-fix-comment-for-current_may_throttle.patch mm-vmscan-fix-comment-for-isolate_lru_pages.patch mm-z3fold-declare-z3fold_mount-with-__init.patch mm-z3fold-remove-obsolete-comment-in-z3fold_alloc.patch mm-z3fold-minor-clean-up-for-z3fold_free.patch mm-z3fold-remove-unneeded-page_mapcount_reset-and-clearpageprivate.patch mm-z3fold-remove-confusing-local-variable-l-reassignment.patch mm-z3fold-move-decrement-of-pool-pages_nr-into-__release_z3fold_page.patch mm-z3fold-remove-redundant-list_del_init-of-zhdr-buddy-in-z3fold_free.patch mm-z3fold-remove-unneeded-page_headless-check-in-free_handle.patch mm-compaction-use-helper-isolation_suitable.patch drivers-base-nodec-fix-compaction-sysfs-file-leak.patch mm-mempolicy-clean-up-the-code-logic-in-queue_pages_pte_range.patch mm-migration-remove-unneeded-local-variable-mapping_locked.patch mm-migration-remove-unneeded-local-variable-page_lru.patch mm-migration-use-helper-function-vma_lookup-in-add_page_for_migration.patch mm-migration-use-helper-macro-min-in-do_pages_stat.patch mm-migration-avoid-unneeded-nodemask_t-initialization.patch mm-migration-remove-some-duplicated-codes-in-migrate_pages.patch mm-migration-fix-potential-page-refcounts-leak-in-migrate_pages.patch mm-migration-fix-potential-invalid-node-access-for-reclaim-based-migration.patch mm-migration-fix-possible-do_pages_stat_array-racing-with-memory-offline.patch mm-madvise-fix-potential-pte_unmap_unlock-pte-error.patch mm-madvise-free-hwpoison-and-swapin-error-entry-in-madvise_free_pte_range.patch mm-compaction-remove-unneeded-return-value-of-kcompactd_run.patch mm-compaction-remove-unneeded-pfn-update.patch mm-compaction-remove-unneeded-assignment-to-isolate_start_pfn.patch mm-compaction-clean-up-comment-for-sched-contention.patch mm-compaction-clean-up-comment-about-suitable-migration-target-recheck.patch mm-compaction-use-compact_cluster_max-in-compactionc.patch mm-compaction-use-helper-compound_nr-in-isolate_migratepages_block.patch mm-compaction-clean-up-comment-about-async-compaction-in-isolate_migratepages.patch mm-compaction-avoid-possible-null-pointer-dereference-in-kcompactd_cpu_online.patch mm-compaction-make-compaction_zonelist_suitable-return-false-when-compact_success.patch mm-compaction-simplify-the-code-in-__compact_finished.patch mm-compaction-make-sure-highest-is-above-the-min_pfn.patch mm-swapfile-unuse_pte-can-map-random-data-if-swap-read-fails.patch mm-swapfile-fix-lost-swap-bits-in-unuse_pte.patch mm-migration-reduce-the-rcu-lock-duration.patch mm-migration-remove-unneeded-lock-page-and-pagemovable-check.patch mm-migration-return-errno-when-isolate_huge_page-failed.patch mm-migration-fix-potential-pte_unmap-on-an-not-mapped-pte.patch mm-vmscan-take-min_slab_pages-into-account-when-try-to-call-shrink_node.patch mm-vmscan-add-a-comment-about-madv_free-pages-check-in-folio_check_dirty_writeback.patch mm-vmscan-introduce-helper-function-reclaim_page_list.patch mm-vmscan-activate-swap-backed-executable-folios-after-first-usage.patch mm-vmscan-take-all-base-pages-of-thp-into-account-when-race-with-speculative-reference.patch mm-vmscan-remove-obsolete-comment-in-kswapd_run.patch mm-vmscan-use-helper-folio_is_file_lru.patch