[RFC 0/4] ZRAM: make it just store the high compression rate page

[Hui Zhu <zhuhui@xiaomi.com>]

Current ZRAM just can store all pages even if the compression rate
of a page is really low.  So the compression rate of ZRAM is out of
control when it is running.
In my part, I did some test and record with ZRAM.  The compression rate
is about 40%.

This series of patches make ZRAM can just store the page that the
compressed size is smaller than a value.
With these patches, I set the value to 2048 and did the same test with
before.  The compression rate is about 20%.  The times of lowmemorykiller
also decreased.

Hui Zhu (4):
vmscan.c: shrink_page_list: unmap anon pages after pageout
Add non-swap page flag to mark a page will not swap
ZRAM: do not swap the pages that compressed size bigger than non_swap
vmscan.c: zram: add non swap support for shmem file pages

 drivers/block/zram/Kconfig     |   11 +++
 drivers/block/zram/zram_drv.c  |   38 +++++++++++
 drivers/block/zram/zram_drv.h  |    4 +
 fs/proc/meminfo.c              |    6 +
 include/linux/mm_inline.h      |   20 +++++
 include/linux/mmzone.h         |    3 
 include/linux/page-flags.h     |    8 ++
 include/linux/rmap.h           |    5 +
 include/linux/shmem_fs.h       |    6 +
 include/trace/events/mmflags.h |    9 ++
 kernel/events/uprobes.c        |   16 ++++
 mm/Kconfig                     |    9 ++
 mm/memory.c                    |   34 ++++++++++
 mm/migrate.c                   |    4 +
 mm/mprotect.c                  |    8 ++
 mm/page_io.c                   |   11 ++-
 mm/rmap.c                      |   23 ++++++
 mm/shmem.c                     |   77 +++++++++++++++++-----
 mm/vmscan.c                    |  139 +++++++++++++++++++++++++++++++++++------
 19 files changed, 387 insertions(+), 44 deletions(-)