Messages in this thread | | | Subject | Re: [PATCH v2 3/3] memcg: increase MEMCG_CHARGE_BATCH to 64 | From | Muchun Song <> | Date | Thu, 25 Aug 2022 16:30:48 +0800 |
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> On Aug 25, 2022, at 08:05, Shakeel Butt <shakeelb@google.com> 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@google.com> > Reported-by: kernel test robot <oliver.sang@intel.com> > Acked-by: Soheil Hassas Yeganeh <soheil@google.com> > Reviewed-by: Feng Tang <feng.tang@intel.com> > Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Muchun Song <songmuchun@bytedance.com>
Thanks.
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