> On Aug 25, 2022, at 08:05, Shakeel Butt <shakeelb@xxxxxxxxxx> wrote: > > For several years, MEMCG_CHARGE_BATCH was kept at 32 but with bigger > machines and the network intensive workloads requiring througput in > Gbps, 32 is too small and makes the memcg charging path a bottleneck. > For now, increase it to 64 for easy acceptance to 6.0. We will need to > revisit this in future for ever increasing demand of higher performance. > > Please note that the memcg charge path drain the per-cpu memcg charge > stock, so there should not be any oom behavior change. Though it does > have impact on rstat flushing and high limit reclaim backoff. > > To evaluate the impact of this optimization, on a 72 CPUs machine, we > ran the following workload in a three level of cgroup hierarchy. > > $ netserver -6 > # 36 instances of netperf with following params > $ netperf -6 -H ::1 -l 60 -t TCP_SENDFILE -- -m 10K > > Results (average throughput of netperf): > Without (6.0-rc1) 10482.7 Mbps > With patch 17064.7 Mbps (62.7% improvement) > > With the patch, the throughput improved by 62.7%. This is very impressive. > > Signed-off-by: Shakeel Butt <shakeelb@xxxxxxxxxx> > Reported-by: kernel test robot <oliver.sang@xxxxxxxxx> > Acked-by: Soheil Hassas Yeganeh <soheil@xxxxxxxxxx> > Reviewed-by: Feng Tang <feng.tang@xxxxxxxxx> > Acked-by: Roman Gushchin <roman.gushchin@xxxxxxxxx> Acked-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> Thanks.
