[stable] upstream d913897abace8 -stable backport request

[Sergey Senozhatsky]

Hello,

Please add upstream 'commit d913897abace8 ("zram: try vmalloc() after
kmalloc()")' to stable releases.

:commit d913897abace843bba20249f3190167f7895e9c3
:Author: Kyeongdon Kim <kyeongdon.kim@xxxxxxx>
:
:    zram: try vmalloc() after kmalloc()
:    
:    When we're using LZ4 multi compression streams for zram swap, we found
:    out page allocation failure message in system running test.  That was
:    not only once, but a few(2 - 5 times per test).  Also, some failure
:    cases were continually occurring to try allocation order 3.
:    
:    In order to make parallel compression private data, we should call
:    kzalloc() with order 2/3 in runtime(lzo/lz4).  But if there is no order
:    2/3 size memory to allocate in that time, page allocation fails.  This
:    patch makes to use vmalloc() as fallback of kmalloc(), this prevents
:    page alloc failure warning.
:    
:    After using this, we never found warning message in running test, also
:    It could reduce process startup latency about 60-120ms in each case.

	-ss