zsmalloc: clean up many BUG_ON
authorMinchan Kim <minchan@kernel.org>
Fri, 20 May 2016 23:59:39 +0000 (16:59 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sat, 21 May 2016 00:58:30 +0000 (17:58 -0700)
commit830e4bc5baa9fda5d45257e9a3dbb3555c6c180e
tree2a889e6e5c7bc4c7061608b73c7bee11258efcf1
parenta42094676f076534bf4998625456fe0bb99c1f1e
zsmalloc: clean up many BUG_ON

There are many BUG_ON in zsmalloc.c which is not recommened so change
them as alternatives.

Normal rule is as follows:

1. avoid BUG_ON if possible. Instead, use VM_BUG_ON or VM_BUG_ON_PAGE

2. use VM_BUG_ON_PAGE if we need to see struct page's fields

3. use those assertion in primitive functions so higher functions can
   rely on the assertion in the primitive function.

4. Don't use assertion if following instruction can trigger Oops

Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/zsmalloc.c