The patch titled
Subject: mm/mremap: use pmd_addr_end to simplify the calculate of extent
has been added to the -mm tree. Its filename is
mm-mremap-use-pmd_addr_end-to-simplify-the-calculate-of-extent.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-mremap-use-pmd_addr_end-to-simplify-the-calculate-of-extent.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-mremap-use-pmd_addr_end-to-simplify-the-calculate-of-extent.patch
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------------------------------------------------------
From: Wei Yang <richard.weiyang@xxxxxxxxxxxxxxxxx>
Subject: mm/mremap: use pmd_addr_end to simplify the calculate of extent
The purpose of this code is to calculate the smaller extent in old and new
range. Let's leverage pmd_addr_end() to do the calculation.
Hope this would make the code easier to read.
Link: http://lkml.kernel.org/r/20200708095028.41706-5-richard.weiyang@xxxxxxxxxxxxxxxxx
Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxxxxxxxxxx>
Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Cc: Dmitry Osipenko <digetx@xxxxxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Cc: Thomas Hellstrom <thellstrom@xxxxxxxxxx>
Cc: Thomas Hellstrom (VMware) <thomas_os@xxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mremap.c | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)
--- a/mm/mremap.c~mm-mremap-use-pmd_addr_end-to-simplify-the-calculate-of-extent
+++ a/mm/mremap.c
@@ -237,11 +237,12 @@ unsigned long move_page_tables(struct vm
unsigned long new_addr, unsigned long len,
bool need_rmap_locks)
{
- unsigned long extent, next, old_end;
+ unsigned long extent, old_next, new_next, old_end, new_end;
struct mmu_notifier_range range;
pmd_t *old_pmd, *new_pmd;
old_end = old_addr + len;
+ new_end = new_addr + len;
flush_cache_range(vma, old_addr, old_end);
mmu_notifier_range_init(&range, MMU_NOTIFY_UNMAP, 0, vma, vma->vm_mm,
@@ -250,14 +251,11 @@ unsigned long move_page_tables(struct vm
for (; old_addr < old_end; old_addr += extent, new_addr += extent) {
cond_resched();
- next = (old_addr + PMD_SIZE) & PMD_MASK;
- /* even if next overflowed, extent below will be ok */
- extent = next - old_addr;
- if (extent > old_end - old_addr)
- extent = old_end - old_addr;
- next = (new_addr + PMD_SIZE) & PMD_MASK;
- if (extent > next - new_addr)
- extent = next - new_addr;
+
+ old_next = pmd_addr_end(old_addr, old_end);
+ new_next = pmd_addr_end(new_addr, new_end);
+ extent = min(old_next - old_addr, new_next - new_addr);
+
old_pmd = get_old_pmd(vma->vm_mm, old_addr);
if (!old_pmd)
continue;
_
Patches currently in -mm which might be from richard.weiyang@xxxxxxxxxxxxxxxxx are
mm-mremap-it-is-sure-to-have-enough-space-when-extent-meets-requirement.patch
mm-mremap-calculate-extent-in-one-place.patch
mm-mremap-start-addresses-are-properly-aligned.patch
mm-mremap-use-pmd_addr_end-to-simplify-the-calculate-of-extent.patch
mm-sparse-never-partially-remove-memmap-for-early-section.patch
mm-sparse-only-sub-section-aligned-range-would-be-populated.patch
mm-page_allocc-replace-the-definition-of-nr_migratetype_bits-with-pb_migratetype_bits.patch
mm-page_allocc-extract-the-common-part-in-pfn_to_bitidx.patch
mm-page_allocc-simplify-pageblock-bitmap-access.patch
mm-page_allocc-remove-unnecessary-end_bitidx-for-_pfnblock_flags_mask.patch
mm-page_alloc-fallbacks-at-most-has-3-elements.patch
