The patch titled
vmalloc: use plain pte_clear() for unmaps
has been added to the -mm tree. Its filename is
vmalloc-use-plain-pte_clear-for-unmaps.patch
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------------------------------------------------------
Subject: vmalloc: use plain pte_clear() for unmaps
From: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
ptep_get_and_clear() is potentially moderately expensive (at least an
atomic operation, or potentially a trap-and-fault when virtualized) so use
a plain pte_clear().
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
Cc: Nick Piggin <npiggin@xxxxxxxxx>
Cc: Hugh Dickins <hugh.dickins@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmalloc.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff -puN mm/vmalloc.c~vmalloc-use-plain-pte_clear-for-unmaps mm/vmalloc.c
--- a/mm/vmalloc.c~vmalloc-use-plain-pte_clear-for-unmaps
+++ a/mm/vmalloc.c
@@ -39,8 +39,9 @@ static void vunmap_pte_range(pmd_t *pmd,
pte = pte_offset_kernel(pmd, addr);
do {
- pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
+ pte_t ptent = *pte;
WARN_ON(!pte_none(ptent) && !pte_present(ptent));
+ pte_clear(&init_mm, addr, pte);
} while (pte++, addr += PAGE_SIZE, addr != end);
}
_
Patches currently in -mm which might be from jeremy.fitzhardinge@xxxxxxxxxx are
linux-next.patch
mm-remove-unused-token-argument-from-apply_to_page_range-callback.patch
mm-add-apply_to_page_range_batch.patch
ioremap-use-apply_to_page_range_batch-for-ioremap_page_range.patch
vmalloc-use-plain-pte_clear-for-unmaps.patch
vmalloc-use-apply_to_page_range_batch-for-vunmap_page_range.patch
vmalloc-use-apply_to_page_range_batch-for-vmap_page_range_noflush.patch
vmalloc-use-apply_to_page_range_batch-in-alloc_vm_area.patch
xen-mmu-use-apply_to_page_range_batch-in-xen_remap_domain_mfn_range.patch
xen-grant-table-use-apply_to_page_range_batch.patch
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