From: "Michal Koutný" <mkoutny@suse.com>
To: Feng Tang <feng.tang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
andi.kleen@intel.com, kernel test robot <oliver.sang@intel.com>,
Roman Gushchin <guro@fb.com>, Michal Hocko <mhocko@suse.com>,
Shakeel Butt <shakeelb@google.com>,
Balbir Singh <bsingharora@gmail.com>, Tejun Heo <tj@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>,
lkp@lists.01.org, kernel test robot <lkp@intel.com>,
"Huang, Ying" <ying.huang@intel.com>,
Zhengjun Xing <zhengjun.xing@linux.intel.com>
Subject: Re: [mm] 2d146aa3aa: vm-scalability.throughput -36.4% regression
Date: Tue, 31 Aug 2021 11:23:04 +0200 [thread overview]
Message-ID: <20210831092304.GA17119@blackbody.suse.cz> (raw)
In-Reply-To: <20210831063036.GA46357@shbuild999.sh.intel.com>
On Tue, Aug 31, 2021 at 02:30:36PM +0800, Feng Tang <feng.tang@intel.com> wrote:
> Yes, I tried many re-arrangement of the members of cgroup_subsys_state,
> and even close members of memcg, but there were no obvious changes.
> What can recover the regresion is adding 128 bytes padding in the css,
> no matter at the start, end or in the middle.
Do you mean the padding added outside the .cgroup--.refcnt members area
also restores the benchmark results? (Or you refer to paddings that move
.cgroup and .refcnt across a cacheline border ?) I'm asking to be sure
we have correct understanding of what members are contended (what's the
frequent writer).
Thanks,
Michal
next prev parent reply other threads:[~2021-08-31 9:23 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-11 3:17 [mm] 2d146aa3aa: vm-scalability.throughput -36.4% regression kernel test robot
2021-08-11 5:59 ` Linus Torvalds
2021-08-11 20:12 ` Johannes Weiner
2021-08-12 3:19 ` Feng Tang
2021-08-16 3:28 ` Feng Tang
2021-08-16 21:41 ` Johannes Weiner
2021-08-17 2:45 ` Feng Tang
2021-08-17 16:47 ` Michal Koutný
2021-08-17 17:10 ` Shakeel Butt
2021-08-18 2:30 ` Feng Tang
2021-08-30 14:51 ` Michal Koutný
2021-08-31 6:30 ` Feng Tang
2021-08-31 9:23 ` Michal Koutný [this message]
2021-09-01 4:50 ` Feng Tang
2021-09-01 15:12 ` Andi Kleen
2021-09-02 1:35 ` Feng Tang
2021-09-02 2:23 ` Andi Kleen
2021-09-02 3:46 ` Feng Tang
2021-09-02 10:53 ` Michal Koutný
2021-09-02 13:39 ` Feng Tang
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