[PATCHv1 0/8] zram: introduce multi-handle entries

[Sergey Senozhatsky]

	ZRAM_HUGE objects are incompressible and each takes a whole
physical page on the zsmalloc side.  zsmalloc pool, naturally, has
some internal memory fragmentation (within size-classes), so what
we can do for ZRAM_HUGE objects is to split them into several
smaller objects (2 at this point) and store those parts individually
in regular size-classes (hence multi-handle entries). This, basically,
lets us to use already allocated (but unused) zspages memory for
ZRAM_HUGE objects, instead of unconditional allocation of 0-order
page for each ZRAM_HUGE object.

v1:
-- reworked ZRAM_SAME patch (added missing slot lock guard for slot
   flags operation, added missing .pages_stored bump, factored out
   into a separate function)
-- renamed mhandle defines and added mhandle tail len define
-- fixed some typos

Sergey Senozhatsky (8):
  zram: cond_resched() in writeback loop
  zram: free slot memory early during write
  zram: remove entry element member
  zram: factor out ZRAM_SAME write
  zram: factor out ZRAM_HUGE write
  zram: factor out ZRAM_HUGE read
  zsmalloc: move ZS_HANDLE_SIZE to zsmalloc header
  zram: introduce multi-handle entries

 drivers/block/zram/zram_drv.c | 368 ++++++++++++++++++++++------------
 drivers/block/zram/zram_drv.h |  12 +-
 include/linux/zsmalloc.h      |   2 +
 mm/zsmalloc.c                 |   2 -
 4 files changed, 249 insertions(+), 135 deletions(-)

-- 
2.47.0.371.ga323438b13-goog