The patch titled thp: pmd_trans_huge migrate bugcheck has been added to the -mm tree. Its filename is thp-pmd_trans_huge-migrate-bugcheck.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/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: thp: pmd_trans_huge migrate bugcheck From: Andrea Arcangeli <aarcange@xxxxxxxxxx> No pmd_trans_huge should ever materialize in migration ptes areas, because we split the hugepage before migration ptes are instantiated. Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx> Acked-by: Rik van Riel <riel@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/mm.h | 1 + mm/memory.c | 5 +++++ mm/migrate.c | 7 ++++++- 3 files changed, 12 insertions(+), 1 deletion(-) diff -puN include/linux/mm.h~thp-pmd_trans_huge-migrate-bugcheck include/linux/mm.h --- a/include/linux/mm.h~thp-pmd_trans_huge-migrate-bugcheck +++ a/include/linux/mm.h @@ -1495,6 +1495,7 @@ struct page *follow_page(struct vm_area_ #define FOLL_FORCE 0x10 /* get_user_pages read/write w/o permission */ #define FOLL_MINOR 0x20 /* do only minor page faults */ #define FOLL_MLOCK 0x40 /* mark page as mlocked */ +#define FOLL_SPLIT 0x80 /* don't return transhuge pages, split them */ typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr, void *data); diff -puN mm/memory.c~thp-pmd_trans_huge-migrate-bugcheck mm/memory.c --- a/mm/memory.c~thp-pmd_trans_huge-migrate-bugcheck +++ a/mm/memory.c @@ -1305,6 +1305,10 @@ struct page *follow_page(struct vm_area_ goto out; } if (pmd_trans_huge(*pmd)) { + if (flags & FOLL_SPLIT) { + split_huge_page_pmd(mm, pmd); + goto split_fallthrough; + } spin_lock(&mm->page_table_lock); if (likely(pmd_trans_huge(*pmd))) { if (unlikely(pmd_trans_splitting(*pmd))) { @@ -1320,6 +1324,7 @@ struct page *follow_page(struct vm_area_ spin_unlock(&mm->page_table_lock); /* fall through */ } +split_fallthrough: if (unlikely(pmd_bad(*pmd))) goto no_page_table; diff -puN mm/migrate.c~thp-pmd_trans_huge-migrate-bugcheck mm/migrate.c --- a/mm/migrate.c~thp-pmd_trans_huge-migrate-bugcheck +++ a/mm/migrate.c @@ -113,6 +113,8 @@ static int remove_migration_pte(struct p goto out; pmd = pmd_offset(pud, addr); + if (pmd_trans_huge(*pmd)) + goto out; if (!pmd_present(*pmd)) goto out; @@ -632,6 +634,9 @@ static int unmap_and_move(new_page_t get /* page was freed from under us. So we are done. */ goto move_newpage; } + if (unlikely(PageTransHuge(page))) + if (unlikely(split_huge_page(page))) + goto move_newpage; /* prepare cgroup just returns 0 or -ENOMEM */ rc = -EAGAIN; @@ -1046,7 +1051,7 @@ static int do_move_page_to_node_array(st if (!vma || pp->addr < vma->vm_start || !vma_migratable(vma)) goto set_status; - page = follow_page(vma, pp->addr, FOLL_GET); + page = follow_page(vma, pp->addr, FOLL_GET|FOLL_SPLIT); err = PTR_ERR(page); if (IS_ERR(page)) _ Patches currently in -mm which might be from aarcange@xxxxxxxxxx are mm-compaction-add-trace-events-for-memory-compaction-activity.patch mm-vmscan-convert-lumpy_mode-into-a-bitmask.patch mm-vmscan-reclaim-order-0-and-use-compaction-instead-of-lumpy-reclaim.patch mm-vmscan-reclaim-order-0-and-use-compaction-instead-of-lumpy-reclaim-fix.patch mm-migration-allow-migration-to-operate-asynchronously-and-avoid-synchronous-compaction-in-the-faster-path.patch mm-migration-allow-migration-to-operate-asynchronously-and-avoid-synchronous-compaction-in-the-faster-path-fix.patch mm-migration-cleanup-migrate_pages-api-by-matching-types-for-offlining-and-sync.patch mm-compaction-perform-a-faster-migration-scan-when-migrating-asynchronously.patch mm-vmscan-rename-lumpy_mode-to-reclaim_mode.patch mm-vmscan-rename-lumpy_mode-to-reclaim_mode-fix.patch thp-ksm-free-swap-when-swapcache-page-is-replaced.patch thp-fix-bad_page-to-show-the-real-reason-the-page-is-bad.patch thp-transparent-hugepage-support-documentation.patch thp-mm-define-madv_hugepage.patch thp-compound_lock.patch thp-alter-compound-get_page-put_page.patch thp-put_page-recheck-pagehead-after-releasing-the-compound_lock.patch thp-update-futex-compound-knowledge.patch thp-clear-compound-mapping.patch thp-add-native_set_pmd_at.patch thp-add-pmd-paravirt-ops.patch thp-no-paravirt-version-of-pmd-ops.patch thp-export-maybe_mkwrite.patch thp-comment-reminder-in-destroy_compound_page.patch thp-config_transparent_hugepage.patch thp-special-pmd_trans_-functions.patch thp-add-pmd-mangling-generic-functions.patch thp-add-pmd-mangling-functions-to-x86.patch thp-bail-out-gup_fast-on-splitting-pmd.patch thp-pte-alloc-trans-splitting.patch thp-add-pmd-mmu_notifier-helpers.patch thp-clear-page-compound.patch thp-add-pmd_huge_pte-to-mm_struct.patch thp-split_huge_page_mm-vma.patch thp-split_huge_page-paging.patch thp-clear_copy_huge_page.patch thp-_gfp_no_kswapd.patch thp-dont-alloc-harder-for-gfp-nomemalloc-even-if-nowait.patch thp-transparent-hugepage-core.patch thp-split_huge_page-anon_vma-ordering-dependency.patch thp-verify-pmd_trans_huge-isnt-leaking.patch thp-madvisemadv_hugepage.patch thp-add-pagetranscompound.patch thp-pmd_trans_huge-migrate-bugcheck.patch thp-memcg-compound.patch thp-transhuge-memcg-commit-tail-pages-at-charge.patch thp-memcg-huge-memory.patch thp-transparent-hugepage-vmstat.patch thp-khugepaged.patch thp-khugepaged-vma-merge.patch thp-skip-transhuge-pages-in-ksm-for-now.patch thp-remove-pg_buddy.patch thp-add-x86-32bit-support.patch thp-mincore-transparent-hugepage-support.patch thp-add-pmd_modify.patch thp-mprotect-pass-vma-down-to-page-table-walkers.patch thp-mprotect-transparent-huge-page-support.patch thp-set-recommended-min-free-kbytes.patch thp-enable-direct-defrag.patch thp-add-numa-awareness-to-hugepage-allocations.patch thp-allocate-memory-in-khugepaged-outside-of-mmap_sem-write-mode.patch thp-transparent-hugepage-config-choice.patch thp-select-config_compaction-if-transparent_hugepage-enabled.patch thp-transhuge-isolate_migratepages.patch thp-avoid-breaking-huge-pmd-invariants-in-case-of-vma_adjust-failures.patch thp-dont-allow-transparent-hugepage-support-without-pse.patch thp-mmu_notifier_test_young.patch thp-freeze-khugepaged-and-ksmd.patch thp-use-compaction-in-kswapd-for-gfp_atomic-order-0.patch thp-use-compaction-for-all-allocation-orders.patch thp-disable-transparent-hugepages-by-default-on-small-systems.patch thp-fix-anon-memory-statistics-with-transparent-hugepages.patch thp-scale-nr_rotated-to-balance-memory-pressure.patch thp-transparent-hugepage-sysfs-meminfo.patch thp-add-debug-checks-for-mapcount-related-invariants.patch thp-fix-memory-failure-hugetlbfs-vs-thp-collision.patch thp-compound_trans_order.patch thp-mm-define-madv_nohugepage.patch thp-madvisemadv_nohugepage.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html