Eric Lee / smarc-ti-linux-kernel | Embedian Git Server

Commit e920e14ca29b0b2a981cfc90e4e20edd6f078d19

Authored by Mel Gorman 2013-10-07 18:28:48 +0800

Committed by Ingo Molnar 2013-10-09 18:39:48 +0800

Exists in master and in 16 other branches

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>

Showing 1 changed file with 2 additions and 1 deletions Side-by-side Diff

mm/mprotect.c

mm/mprotect.c

Diff comments View file @ e920e14

...	...	@@ -101,8 +101,9 @@
101	101	make_migration_entry_read(&entry);
102	102	set_pte_at(mm, addr, pte,
103	103	swp_entry_to_pte(entry));
	104	+
	105	+ pages++;
104	106	}
105		- pages++;
106	107	}
107	108	} while (pte++, addr += PAGE_SIZE, addr != end);
108	109	arch_leave_lazy_mmu_mode();