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| author | Mel Gorman <mgorman@suse.de> | 2013-10-07 11:28:48 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2013-10-09 12:39:48 +0200 |
| commit | e920e14ca29b0b2a981cfc90e4e20edd6f078d19 (patch) | |
| tree | e8f8530aaddb664bc811289aa0e096890a40dd2e /mm/mprotect.c | |
| parent | afcae2655b0ab67e65f161b1bb214efcfa1db415 (diff) | |
| download | linux-e920e14ca29b0b2a981cfc90e4e20edd6f078d19.tar.gz linux-e920e14ca29b0b2a981cfc90e4e20edd6f078d19.tar.bz2 linux-e920e14ca29b0b2a981cfc90e4e20edd6f078d19.zip | |
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 <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-11-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'mm/mprotect.c')
| -rw-r--r-- | mm/mprotect.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/mprotect.c b/mm/mprotect.c index 2bbb648ea73f..7bdbd4b0f6d9 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(); |