When insert and delete a vma, it will compute and propagate related subtree gap. After some investigation, we can reduce subtree gap propagation a little. [1]: This one reduce the propagation by update *next* gap after itself, since *next* must be a parent in this case. [2]: This one achieve this by unlinking vma from list. After applying these two patches, test shows it reduce 0.4% function all for vma_compute_subtree_gap. Wei Yang (2): mm/mmap.c: update *next* gap after itself mm/mmap.c: unlink vma before rb_erase mm/mmap.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) -- 2.17.1