mm: numa: do not clear PTE for pte_numa update
authorMel Gorman <mgorman@suse.de>
Thu, 19 Dec 2013 01:08:37 +0000 (17:08 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 19 Dec 2013 03:04:51 +0000 (19:04 -0800)
commit0c5f83c23ca703d32f930393825487257a5cde6d
tree380066a66f3f36fa56c5a772e289ef4f06d3c1ec
parent5a6dac3ec5f583cc8ee7bc53b5500a207c4ca433
mm: numa: do not clear PTE for pte_numa update

The TLB must be flushed if the PTE is updated but change_pte_range is
clearing the PTE while marking PTEs pte_numa without necessarily
flushing the TLB if it reinserts the same entry.  Without the flush,
it's conceivable that two processors have different TLBs for the same
virtual address and at the very least it would generate spurious faults.

This patch only unmaps the pages in change_pte_range for a full
protection change.

[riel@redhat.com: write pte_numa pte back to the page tables]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Chegu Vinod <chegu_vinod@hp.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/mprotect.c