The patch titled
Subject: thp: fix zap_huge_pmd() for DAX
has been added to the -mm tree. Its filename is
thp-fix-zap_huge_pmd-for-dax.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/thp-fix-zap_huge_pmd-for-dax.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/thp-fix-zap_huge_pmd-for-dax.patch
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------------------------------------------------------
From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Subject: thp: fix zap_huge_pmd() for DAX
The original DAX code assumed that pgtable_t was a pointer, which isn't
true on all architectures. Restructure the code to not rely on that
assumption.
[willy@xxxxxxxxxxxxxxx: further fixes integrated into this patch]
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 71 +++++++++++++++++++--------------------------
1 file changed, 31 insertions(+), 40 deletions(-)
diff -puN mm/huge_memory.c~thp-fix-zap_huge_pmd-for-dax mm/huge_memory.c
--- a/mm/huge_memory.c~thp-fix-zap_huge_pmd-for-dax
+++ a/mm/huge_memory.c
@@ -1456,50 +1456,41 @@ out:
int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
pmd_t *pmd, unsigned long addr)
{
+ pmd_t orig_pmd;
spinlock_t *ptl;
- int ret = 0;
- if (__pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
- pgtable_t pgtable;
- pmd_t orig_pmd;
- /*
- * For architectures like ppc64 we look at deposited pgtable
- * when calling pmdp_huge_get_and_clear. So do the
- * pgtable_trans_huge_withdraw after finishing pmdp related
- * operations.
- */
- orig_pmd = pmdp_huge_get_and_clear_full(tlb->mm, addr, pmd,
- tlb->fullmm);
- tlb_remove_pmd_tlb_entry(tlb, pmd, addr);
- if (vma_is_dax(vma)) {
- if (is_huge_zero_pmd(orig_pmd)) {
- pgtable = NULL;
- } else {
- spin_unlock(ptl);
- return 1;
- }
- } else {
- pgtable = pgtable_trans_huge_withdraw(tlb->mm, pmd);
- }
- if (is_huge_zero_pmd(orig_pmd)) {
- atomic_long_dec(&tlb->mm->nr_ptes);
- spin_unlock(ptl);
+ if (__pmd_trans_huge_lock(pmd, vma, &ptl) != 1)
+ return 0;
+ /*
+ * For architectures like ppc64 we look at deposited pgtable
+ * when calling pmdp_huge_get_and_clear. So do the
+ * pgtable_trans_huge_withdraw after finishing pmdp related
+ * operations.
+ */
+ orig_pmd = pmdp_huge_get_and_clear_full(tlb->mm, addr, pmd,
+ tlb->fullmm);
+ tlb_remove_pmd_tlb_entry(tlb, pmd, addr);
+ if (vma_is_dax(vma)) {
+ spin_unlock(ptl);
+ if (is_huge_zero_pmd(orig_pmd))
put_huge_zero_page();
- } else {
- struct page *page = pmd_page(orig_pmd);
- page_remove_rmap(page);
- VM_BUG_ON_PAGE(page_mapcount(page) < 0, page);
- add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR);
- VM_BUG_ON_PAGE(!PageHead(page), page);
- atomic_long_dec(&tlb->mm->nr_ptes);
- spin_unlock(ptl);
- tlb_remove_page(tlb, page);
- }
- if (pgtable)
- pte_free(tlb->mm, pgtable);
- ret = 1;
+ } else if (is_huge_zero_pmd(orig_pmd)) {
+ pte_free(tlb->mm, pgtable_trans_huge_withdraw(tlb->mm, pmd));
+ atomic_long_dec(&tlb->mm->nr_ptes);
+ spin_unlock(ptl);
+ put_huge_zero_page();
+ } else {
+ struct page *page = pmd_page(orig_pmd);
+ page_remove_rmap(page);
+ VM_BUG_ON_PAGE(page_mapcount(page) < 0, page);
+ add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR);
+ VM_BUG_ON_PAGE(!PageHead(page), page);
+ pte_free(tlb->mm, pgtable_trans_huge_withdraw(tlb->mm, pmd));
+ atomic_long_dec(&tlb->mm->nr_ptes);
+ spin_unlock(ptl);
+ tlb_remove_page(tlb, page);
}
- return ret;
+ return 1;
}
int move_huge_pmd(struct vm_area_struct *vma, struct vm_area_struct *new_vma,
_
Patches currently in -mm which might be from kirill.shutemov@xxxxxxxxxxxxxxx are
user_ns-use-correct-check-for-single-threadedness.patch
mm-mlock-refactor-mlock-munlock-and-munlockall-code.patch
mm-mlock-add-new-mlock-system-call.patch
mm-introduce-vm_lockonfault.patch
mm-mlock-add-mlock-flags-to-enable-vm_lockonfault-usage.patch
selftests-vm-add-tests-for-lock-on-fault.patch
mips-add-entry-for-new-mlock2-syscall.patch
mm-fix-status-code-move_pages-returns-for-zero-page.patch
mm-make-gup-handle-pfn-mapping-unless-foll_get-is-requested.patch
mm-make-gup-handle-pfn-mapping-unless-foll_get-is-requested-fix.patch
mremap-dont-leak-new_vma-if-f_op-mremap-fails.patch
mm-move-mremap-from-file_operations-to-vm_operations_struct.patch
mremap-dont-do-mm_populatenew_addr-on-failure.patch
mremap-dont-do-uneccesary-checks-if-new_len-==-old_len.patch
mremap-simplify-the-overlap-check-in-mremap_to.patch
mm-introduce-vma_is_anonymousvma-helper.patch
mmap-fix-the-usage-of-vm_pgoff-in-special_mapping-paths.patch
mremap-fix-the-wrong-vma-vm_file-check-in-copy_vma.patch
thp-vma_adjust_trans_huge-adjust-file-backed-vma-too.patch
dax-move-dax-related-functions-to-a-new-header.patch
thp-prepare-for-dax-huge-pages.patch
mm-add-a-pmd_fault-handler.patch
mm-export-various-functions-for-the-benefit-of-dax.patch
mm-add-vmf_insert_pfn_pmd.patch
dax-add-huge-page-fault-support.patch
ext2-huge-page-fault-support.patch
ext4-huge-page-fault-support.patch
xfs-huge-page-fault-support.patch
thp-decrement-refcount-on-huge-zero-page-if-it-is-split.patch
thp-fix-zap_huge_pmd-for-dax.patch
dax-dont-use-set_huge_zero_page.patch
dax-ensure-that-zero-pages-are-removed-from-other-processes.patch
mm-page_isolation-remove-bogus-tests-for-isolated-pages.patch
mm-rename-and-move-get-set_freepage_migratetype.patch
mempolicy-get-rid-of-duplicated-check-for-vmavm_pfnmap-in-queue_pages_range.patch
vm_flags-vm_flags_t-and-__nocast.patch
page-flags-trivial-cleanup-for-pagetrans-helpers.patch
page-flags-introduce-page-flags-policies-wrt-compound-pages.patch
page-flags-define-pg_locked-behavior-on-compound-pages.patch
page-flags-define-behavior-of-fs-io-related-flags-on-compound-pages.patch
page-flags-define-behavior-of-lru-related-flags-on-compound-pages.patch
page-flags-define-behavior-of-lru-related-flags-on-compound-pages-fix.patch
page-flags-define-behavior-slb-related-flags-on-compound-pages.patch
page-flags-define-behavior-of-xen-related-flags-on-compound-pages.patch
page-flags-define-pg_reserved-behavior-on-compound-pages.patch
page-flags-define-pg_swapbacked-behavior-on-compound-pages.patch
page-flags-define-pg_swapcache-behavior-on-compound-pages.patch
page-flags-define-pg_mlocked-behavior-on-compound-pages.patch
page-flags-define-pg_uncached-behavior-on-compound-pages.patch
page-flags-define-pg_uptodate-behavior-on-compound-pages.patch
page-flags-look-on-head-page-if-the-flag-is-encoded-in-page-mapping.patch
mm-sanitize-page-mapping-for-tail-pages.patch
include-linux-page-flagsh-rename-macros-to-avoid-collisions.patch
fix-list_poison12-offset.patch
use-poison_pointer_delta-for-poison-pointers.patch
remove-not-used-poison-pointer-macros.patch
mm-mark-most-vm_operations_struct-const.patch
mm-mpx-add-vm_flags_t-vm_flags-arg-to-do_mmap_pgoff.patch
mm-make-sure-all-file-vmas-have-vm_ops-set.patch
mm-use-vma_is_anonymous-in-create_huge_pmd-and-wp_huge_pmd.patch
mm-madvise-use-vma_is_anonymous-to-check-for-anon-vma.patch
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