Re: [stable] upstream d913897abace8 -stable backport request
From: Sergey Senozhatsky
Date: Mon Jan 25 2016 - 08:02:50 EST
On (01/25/16 21:50), Sergey Senozhatsky wrote:
> 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.