Messages in this thread Patch in this message | | | From | Mel Gorman <> | Subject | [PATCH 14/27] mm: Do not flush TLB during protection change if !pte_present && !migration_entry | Date | Thu, 8 Aug 2013 15:00:26 +0100 |
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NUMA PTE scanning is expensive both in terms of the scanning itself and the TLB flush if there are any updates. Currently non-present PTEs are accounted for as an update and incurring a TLB flush where it is only necessary for anonymous migration entries. This patch addresses the problem and should reduce TLB flushes.
Signed-off-by: Mel Gorman <mgorman@suse.de> --- mm/mprotect.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/mm/mprotect.c b/mm/mprotect.c index 1f4ab1c..8e7e9bd 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -101,8 +101,9 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, make_migration_entry_read(&entry); set_pte_at(mm, addr, pte, swp_entry_to_pte(entry)); + + pages++; } - pages++; } } while (pte++, addr += PAGE_SIZE, addr != end); arch_leave_lazy_mmu_mode(); -- 1.8.1.4
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