On Fri, 4 Sep 2015, Sergey Senozhatsky wrote:

> But I went through the corresponding slabinfo (I track slabinfo too); and yes,
> zero unused objects.

Please use the slabinfo tool. What you see in /proc/slabinfo is generated
for slab compatibility and may not show useful numbers.

Run

	gcc -o slabinfo tools/vm/slabinfo.c

	slabinfo -T

to get an overview of the fragmentation etc state of the
slab caches.

Run

	slabinfo

to get individual cache statistics


It would be helpful to compare the output with and without merging.