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Date:   Fri, 24 Jun 2022 14:43:58 +0000
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Subject: Re: [net] 4890b686f4: netperf.Throughput_Mbps -69.4% regression
From:   Shakeel Butt <shakeelb@google.com>
To:     Feng Tang <feng.tang@intel.com>
Cc:     Eric Dumazet <edumazet@google.com>, Linux MM <linux-mm@kvack.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Roman Gushchin <roman.gushchin@linux.dev>,
        Michal Hocko <mhocko@kernel.org>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Muchun Song <songmuchun@bytedance.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Xin Long <lucien.xin@gmail.com>,
        Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>,
        kernel test robot <oliver.sang@intel.com>,
        Soheil Hassas Yeganeh <soheil@google.com>,
        LKML <linux-kernel@vger.kernel.org>,
        network dev <netdev@vger.kernel.org>,
        linux-s390@vger.kernel.org, MPTCP Upstream <mptcp@lists.linux.dev>,
        "linux-sctp @ vger . kernel . org" <linux-sctp@vger.kernel.org>,
        lkp@lists.01.org, kbuild test robot <lkp@intel.com>,
        Huang Ying <ying.huang@intel.com>,
        Xing Zhengjun <zhengjun.xing@linux.intel.com>,
        Yin Fengwei <fengwei.yin@intel.com>, Ying Xu <yinxu@redhat.com>
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On Fri, Jun 24, 2022 at 03:06:56PM +0800, Feng Tang wrote:
> On Thu, Jun 23, 2022 at 11:34:15PM -0700, Shakeel Butt wrote:
[...]
> > 
> > Feng, can you please explain the memcg setup on these test machines
> > and if the tests are run in root or non-root memcg?
> 
> I don't know the exact setup, Philip/Oliver from 0Day can correct me.
> 
> I logged into a test box which runs netperf test, and it seems to be
> cgoup v1 and non-root memcg. The netperf tasks all sit in dir:
> '/sys/fs/cgroup/memory/system.slice/lkp-bootstrap.service'
> 

Thanks Feng. Can you check the value of memory.kmem.tcp.max_usage_in_bytes
in /sys/fs/cgroup/memory/system.slice/lkp-bootstrap.service after making
sure that the netperf test has already run?

If this is non-zero then network memory accounting is enabled and the
slowdown is expected.

> And the rootfs is a debian based rootfs
> 
> Thanks,
> Feng
> 
> 
> > thanks,
> > Shakeel