Comment # 1 on bug 1206848 from Michal Hocko

Could you collect /proc/vmstat during that time period (say every second)[1]?

[1] You can use collect_logs from mmdebug-tools package from
https://build.opensuse.org/package/binaries/home:mhocko/mmdebug-tools/openSUSE_Tumbleweed
The command then would be 
collect_logs -t1s -i /proc/vmstat -o vmstat.log