mm/debug_pagealloc.c: don't allocate page_ext if we don't use guard page

What debug_pagealloc does is just mapping/unmapping page table.
Basically, it doesn't need additional memory space to memorize
something.  But, with guard page feature, it requires additional memory
to distinguish if the page is for guard or not.  Guard page is only used
when debug_guardpage_minorder is non-zero so this patch removes
additional memory allocation (page_ext) if debug_guardpage_minorder is
zero.

It saves memory if we just use debug_pagealloc and not guard page.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Joonsoo Kim <[email protected]>
Reviewed-by: Sergey Senozhatsky <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Michal Hocko <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions