Hello Minchan,
the main use case where I see unacceptably long stalls in UI with
zsmalloc is switching between users in Android.
There is a way to automate user creation and switching between them so
the test I run both to get vmstat statistics and to profile stalls is
to create a user, switch to it and switch back. Each test cycle does
that 10 times, and all the results presented below are averages for 20
runs.
Kernel configurations used for testing:
(1): vanilla
(2): (1) plus "make SLUB atomic" patch [1]
(3): (1) with zbud instead of zsmalloc
(4): (2) with compaction defer logic mostly disabled