The attached patch fixes long latencies in unmap_vmas().  We had lockbreak
code in that function already but it did not take delayed effects of
TLB-gather into account.

Has been tested as part of the -VP patchset.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>