mm: vmalloc: clean up vunmap to avoid pgtable ops twice

vunmap does page table clear operations twice in the case when
DEBUG_PAGEALLOC_ENABLE_DEFAULT is enabled.

So, clean up the code as that is unintended.

As a perf gain, we save few us.  Below ftrace data was obtained while
doing 1 MB of vmalloc/vfree on ARM64 based SoC *without* this patch
applied.  After this patch, we can save ~3 us (on 1 extra
vunmap_page_range).

  CPU  DURATION                  FUNCTION CALLS
  |     |   |                     |   |   |   |
 6)               |  __vunmap() {
 6)               |    vmap_debug_free_range() {
 6)   3.281 us    |      vunmap_page_range();
 6) + 45.468 us   |    }
 6)   2.760 us    |    vunmap_page_range();
 6) ! 505.105 us  |  }

[[email protected]: v3]
  Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Chintan Pandya <[email protected]>
Reviewed-by: Andrew Morton <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Laura Abbott <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Florian Fainelli <[email protected]>
Cc: Yisheng Xie <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Wei Yang <[email protected]>
Cc: Byungchul Park <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions