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>
---
mm/vmalloc.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 5ddbdfe..c06dc1e 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -39,8 +39,9 @@ static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end)
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);
}
--
1.7.3.4
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