From: Chen Yu <yu.c.chen@intel.com>
To: "Huang, Ying" <ying.huang@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>,
kernel test robot <oliver.sang@intel.com>,
Rui Zhang <rui.zhang@intel.com>, Len Brown <len.brown@intel.com>,
"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
0day robot <lkp@intel.com>, Yang Shi <shy828301@gmail.com>,
Zi Yan <ziy@nvidia.com>, Michal Hocko <mhocko@suse.com>,
Wei Xu <weixugc@google.com>, Oscar Salvador <osalvador@suse.de>,
David Rientjes <rientjes@google.com>,
Dan Williams <dan.j.williams@intel.com>,
David Hildenbrand <david@redhat.com>,
Greg Thelen <gthelen@google.com>, Keith Busch <kbusch@kernel.org>,
Yang Shi <yang.shi@linux.alibaba.com>,
LKML <linux-kernel@vger.kernel.org>,
lkp@lists.01.org, feng.tang@intel.com,
zhengjun.xing@linux.intel.com, dave.hansen@linux.intel.com,
linux-mm@kvack.org, mm-commits@vger.kernel.org,
torvalds@linux-foundation.org
Subject: Re: [mm/migrate] 9eeb73028c: stress-ng.memhotplug.ops_per_sec -53.8% regression
Date: Mon, 6 Sep 2021 14:09:08 +0800 [thread overview]
Message-ID: <20210906060908.GA17483@chenyu5-mobl1> (raw)
In-Reply-To: <87lf4ai6u3.fsf@yhuang6-desk2.ccr.corp.intel.com>
On Mon, Sep 06, 2021 at 01:57:56PM +0800, Huang, Ying wrote:
> Dave Hansen <dave.hansen@intel.com> writes:
>
> > On 9/5/21 6:53 PM, Huang, Ying wrote:
> >>> in testcase: stress-ng
> >>> on test machine: 96 threads 2 sockets Intel(R) Xeon(R) Gold 6252 CPU @ 2.10GHz with 192G memory
> >>> with following parameters:
> >>>
> >>> nr_threads: 10%
> >>> disk: 1HDD
> >>> testtime: 60s
> >>> fs: ext4
> >>> class: os
> >>> test: memhotplug
> >>> cpufreq_governor: performance
> >>> ucode: 0x5003006
> >>>
> >> Because we added some operations during online/offline CPU, it's
> >> expected that the performance of online/offline CPU will decrease. In
> >> most cases, the performance of CPU hotplug isn't a big problem. But
> >> then I remembers that the performance of the CPU hotplug may influence
> >> suspend/resume performance :-(
> >>
> >> It appears that it is easy and reasonable to enclose the added
> >> operations inside #ifdef CONFIG_NUMA. Is this sufficient to restore the
> >> performance of suspend/resume?
> >
> > It's "memhotplug", not CPUs, right?
>
> Yes. Thanks for pointing that out!
>
> We will update node_demotion[] in CPU hotplug too. Because the status
> that whether a node has CPU may change after CPU hotplug. And CPU
> online/offline performance may be relevant for suspend/resume.
>
Rui and I took a look at the default kernel config, it seems that CONFIG_NUMA is
enabled on laptops on some distributions. Maybe a runtime detecting flag indicating
that whether this system has enabled NUMA (static key eg) would be an option too, so as
not to enable node_demotion[] on non-NUMA laptops/desktops.
thanks,
Chenyu
next prev parent reply other threads:[~2021-09-06 6:09 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20210902215909.0aWLE2-rh%akpm@linux-foundation.org>
2021-09-05 13:59 ` [mm/migrate] 9eeb73028c: stress-ng.memhotplug.ops_per_sec -53.8% regression kernel test robot
2021-09-06 1:53 ` Huang, Ying
2021-09-06 3:57 ` Dave Hansen
2021-09-06 5:57 ` Huang, Ying
2021-09-06 6:09 ` Chen Yu [this message]
2021-09-06 8:31 ` Huang, Ying
2021-09-17 3:14 ` Huang, Ying
2021-10-21 14:29 ` Oliver Sang
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