Commit-ID: e920e14ca29b0b2a981cfc90e4e20edd6f078d19 Gitweb: http://git.kernel.org/tip/e920e14ca29b0b2a981cfc90e4e20edd6f078d19 Author: Mel Gorman <[email protected]> AuthorDate: Mon, 7 Oct 2013 11:28:48 +0100 Committer: Ingo Molnar <[email protected]> CommitDate: Wed, 9 Oct 2013 12:39:48 +0200
mm: Do not flush TLB during protection change if !pte_present && !migration_entry 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. Cc: Andrea Arcangeli <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Srikar Dronamraju <[email protected]> Reviewed-by: Rik van Riel <[email protected]> Signed-off-by: Mel Gorman <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- mm/mprotect.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/mprotect.c b/mm/mprotect.c index 2bbb648..7bdbd4b 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(); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
