staging: Add Snappy compression support to zram
drivers/staging/zram: backport zram from 3.7 kernel
drivers/staging/zram: adapt to 3.0 kernel
staging: zram: add Crypto API support
staging: zram: add per-cpu support to Crypto
 zram: optimize memory operations with clear_page()/copy_page()

Some architectures provides architecture-specific, optimized version of
clear_page()/copy_page(), which may have better performance than
memset()/memcpy(). So use clear_page()/copy_page() to optimize zram
performance if possible.
Backported ZCache mechanism from Linux Kernel 3.9.11
adapt zcache from 3.9  to 3.0 kernel
backport frontswap from kernel 3.9
update zcache to kernel 3.11
update zsmalloc to kernel 3.11
adapt zram to  zsmalloc from 3.11 kernel
Backport zbud from kernel 3.11
adapt frontswap to 3.0 kernel
Add zswap backend from Linux kernel 3.11
fix mm/kconfig
update frontswap to 3.11 kernel
update cleancache to 3.11 kernel
zbud from 3.11 kernel
zswap and zbud enabled