The patch titled
Subject: mm/page_vma_mapped: reformat map_pte() with less indentation
has been added to the -mm mm-unstable branch. Its filename is
mm-page_vma_mapped-reformat-map_pte-with-less-indentation.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-page_vma_mapped-reformat-map_pte-with-less-indentation.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Hugh Dickins <hughd@xxxxxxxxxx>
Subject: mm/page_vma_mapped: reformat map_pte() with less indentation
Date: Thu, 8 Jun 2023 18:14:12 -0700 (PDT)
No functional change here, but adjust the format of map_pte() so that the
following commit will be easier to read: separate out the PVMW_SYNC case
first, and remove two levels of indentation from the ZONE_DEVICE case.
Link: https://lkml.kernel.org/r/bf723f59-e3fc-6839-1cc3-c0631ee248bc@xxxxxxxxxx
Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Alistair Popple <apopple@xxxxxxxxxx>
Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Cc: Axel Rasmussen <axelrasmussen@xxxxxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: Ira Weiny <ira.weiny@xxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Lorenzo Stoakes <lstoakes@xxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
Cc: Ralph Campbell <rcampbell@xxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: SeongJae Park <sj@xxxxxxxxxx>
Cc: Song Liu <song@xxxxxxxxxx>
Cc: Steven Price <steven.price@xxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Cc: Yu Zhao <yuzhao@xxxxxxxxxx>
Cc: Zack Rusin <zackr@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_vma_mapped.c | 65 +++++++++++++++++++++--------------------
1 file changed, 34 insertions(+), 31 deletions(-)
--- a/mm/page_vma_mapped.c~mm-page_vma_mapped-reformat-map_pte-with-less-indentation
+++ a/mm/page_vma_mapped.c
@@ -15,38 +15,41 @@ static inline bool not_found(struct page
static bool map_pte(struct page_vma_mapped_walk *pvmw)
{
- pvmw->pte = pte_offset_map(pvmw->pmd, pvmw->address);
- if (!(pvmw->flags & PVMW_SYNC)) {
- if (pvmw->flags & PVMW_MIGRATION) {
- if (!is_swap_pte(*pvmw->pte))
- return false;
- } else {
- /*
- * We get here when we are trying to unmap a private
- * device page from the process address space. Such
- * page is not CPU accessible and thus is mapped as
- * a special swap entry, nonetheless it still does
- * count as a valid regular mapping for the page (and
- * is accounted as such in page maps count).
- *
- * So handle this special case as if it was a normal
- * page mapping ie lock CPU page table and returns
- * true.
- *
- * For more details on device private memory see HMM
- * (include/linux/hmm.h or mm/hmm.c).
- */
- if (is_swap_pte(*pvmw->pte)) {
- swp_entry_t entry;
+ if (pvmw->flags & PVMW_SYNC) {
+ /* Use the stricter lookup */
+ pvmw->pte = pte_offset_map_lock(pvmw->vma->vm_mm, pvmw->pmd,
+ pvmw->address, &pvmw->ptl);
+ return true;
+ }
- /* Handle un-addressable ZONE_DEVICE memory */
- entry = pte_to_swp_entry(*pvmw->pte);
- if (!is_device_private_entry(entry) &&
- !is_device_exclusive_entry(entry))
- return false;
- } else if (!pte_present(*pvmw->pte))
- return false;
- }
+ pvmw->pte = pte_offset_map(pvmw->pmd, pvmw->address);
+ if (pvmw->flags & PVMW_MIGRATION) {
+ if (!is_swap_pte(*pvmw->pte))
+ return false;
+ } else if (is_swap_pte(*pvmw->pte)) {
+ swp_entry_t entry;
+ /*
+ * Handle un-addressable ZONE_DEVICE memory.
+ *
+ * We get here when we are trying to unmap a private
+ * device page from the process address space. Such
+ * page is not CPU accessible and thus is mapped as
+ * a special swap entry, nonetheless it still does
+ * count as a valid regular mapping for the page
+ * (and is accounted as such in page maps count).
+ *
+ * So handle this special case as if it was a normal
+ * page mapping ie lock CPU page table and return true.
+ *
+ * For more details on device private memory see HMM
+ * (include/linux/hmm.h or mm/hmm.c).
+ */
+ entry = pte_to_swp_entry(*pvmw->pte);
+ if (!is_device_private_entry(entry) &&
+ !is_device_exclusive_entry(entry))
+ return false;
+ } else if (!pte_present(*pvmw->pte)) {
+ return false;
}
pvmw->ptl = pte_lockptr(pvmw->vma->vm_mm, pvmw->pmd);
spin_lock(pvmw->ptl);
_
Patches currently in -mm which might be from hughd@xxxxxxxxxx are
arm-allow-pte_offset_map-to-fail.patch
arm64-allow-pte_offset_map-to-fail.patch
arm64-hugetlb-pte_alloc_huge-pte_offset_huge.patch
ia64-hugetlb-pte_alloc_huge-pte_offset_huge.patch
m68k-allow-pte_offset_map-to-fail.patch
microblaze-allow-pte_offset_map-to-fail.patch
mips-update_mmu_cache-can-replace-__update_tlb.patch
mips-update_mmu_cache-can-replace-__update_tlb-fix.patch
parisc-add-pte_unmap-to-balance-get_ptep.patch
parisc-unmap_uncached_pte-use-pte_offset_kernel.patch
parisc-hugetlb-pte_alloc_huge-pte_offset_huge.patch
powerpc-kvmppc_unmap_free_pmd-pte_offset_kernel.patch
powerpc-allow-pte_offset_map-to-fail.patch
powerpc-hugetlb-pte_alloc_huge.patch
riscv-hugetlb-pte_alloc_huge-pte_offset_huge.patch
s390-allow-pte_offset_map_lock-to-fail.patch
s390-gmap-use-pte_unmap_unlock-not-spin_unlock.patch
sh-hugetlb-pte_alloc_huge-pte_offset_huge.patch
sparc-hugetlb-pte_alloc_huge-pte_offset_huge.patch
sparc-allow-pte_offset_map-to-fail.patch
sparc-iounit-and-iommu-use-pte_offset_kernel.patch
x86-allow-get_locked_pte-to-fail.patch
x86-sme_populate_pgd-use-pte_offset_kernel.patch
xtensa-add-pte_unmap-to-balance-pte_offset_map.patch
mm-use-pmdp_get_lockless-without-surplus-barrier.patch
mm-migrate-remove-cruft-from-migration_entry_waits.patch
mm-pgtable-kmap_local_page-instead-of-kmap_atomic.patch
mm-pgtable-allow-pte_offset_map-to-fail.patch
mm-filemap-allow-pte_offset_map_lock-to-fail.patch
mm-page_vma_mapped-delete-bogosity-in-page_vma_mapped_walk.patch
mm-page_vma_mapped-reformat-map_pte-with-less-indentation.patch
mm-page_vma_mapped-pte_offset_map_nolock-not-pte_lockptr.patch
mm-pagewalkers-action_again-if-pte_offset_map_lock-fails.patch
mm-pagewalk-walk_pte_range-allow-for-pte_offset_map.patch
mm-vmwgfx-simplify-pmd-pud-mapping-dirty-helpers.patch
mm-vmalloc-vmalloc_to_page-use-pte_offset_kernel.patch
mm-hmm-retry-if-pte_offset_map-fails.patch
mm-userfaultfd-retry-if-pte_offset_map-fails.patch
mm-userfaultfd-allow-pte_offset_map_lock-to-fail.patch
mm-debug_vm_pgtablepage_table_check-warn-pte-map-fails.patch
mm-various-give-up-if-pte_offset_map-fails.patch
mm-mprotect-delete-pmd_none_or_clear_bad_unless_trans_huge.patch
mm-mremap-retry-if-either-pte_offset_map_lock-fails.patch
mm-madvise-clean-up-pte_offset_map_lock-scans.patch
mm-madvise-clean-up-force_shm_swapin_readahead.patch
mm-swapoff-allow-pte_offset_map-to-fail.patch
mm-mglru-allow-pte_offset_map_nolock-to-fail.patch
mm-migrate_device-allow-pte_offset_map_lock-to-fail.patch
mm-gup-remove-foll_split_pmd-use-of-pmd_trans_unstable.patch
mm-huge_memory-split-huge-pmd-under-one-pte_offset_map.patch
mm-khugepaged-allow-pte_offset_map-to-fail.patch
mm-memory-allow-pte_offset_map-to-fail.patch
mm-memory-handle_pte_fault-use-pte_offset_map_nolock.patch
mm-pgtable-delete-pmd_trans_unstable-and-friends.patch
mm-swap-swap_vma_readahead-do-the-pte_offset_map.patch
perf-core-allow-pte_offset_map-to-fail.patch
