Yan Markman
New Member
I'm started with NUMA on Kernel-4.14 arch-arm64 and see that vnstat.c::refresh_cpu_vm_stats
is the most cpu-consumptive on the "perf top" and takes 13% in the IPERF loopback test described below.
The NUMA is adding several atomic-counters in VMSTAT which obviously cause for this performance problem.
Is it known problem?
Is there any graceful fix in latest Kernel versions?
--------------------------------------------------
TEST:
1). Run iperf-server on CPU0:
# taskset 0x1 iperf3 -s -D
2). Run iperf-client on CPU1 over Local-loop IP:
# taskset 0x2 iperf3 -c 127.0.0.1 -t30 -i0 &
3). Run perf top of server's CPU:
# perf top -C 0
The refresh_cpu_vm_stats() is most consumptive on top of list with 13% out of 100% CPU loading.
If modify vmstat.c with "blank" NUMA statistic the CPU loading is 87% and stats() is not seen at all on top-list.
is the most cpu-consumptive on the "perf top" and takes 13% in the IPERF loopback test described below.
The NUMA is adding several atomic-counters in VMSTAT which obviously cause for this performance problem.
Is it known problem?
Is there any graceful fix in latest Kernel versions?
--------------------------------------------------
TEST:
1). Run iperf-server on CPU0:
# taskset 0x1 iperf3 -s -D
2). Run iperf-client on CPU1 over Local-loop IP:
# taskset 0x2 iperf3 -c 127.0.0.1 -t30 -i0 &
3). Run perf top of server's CPU:
# perf top -C 0
The refresh_cpu_vm_stats() is most consumptive on top of list with 13% out of 100% CPU loading.
If modify vmstat.c with "blank" NUMA statistic the CPU loading is 87% and stats() is not seen at all on top-list.
