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From: Jakub Racek <jracek@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Len Brown <lenb@kernel.org>,
	linux-acpi@vger.kernel.org, jracek@redhat.com
Subject: [4.17 regression] Performance drop on kernel-4.17 visible on Stream, Linpack and NAS parallel benchmarks
Date: Wed, 6 Jun 2018 14:27:32 +0200	[thread overview]
Message-ID: <20180606122731.GB27707@jra-laptop.brq.redhat.com> (raw)

Hi,

There is a huge performance regression on the 2 and 4 NUMA node systems on stream 
benchmark with 4.17 kernel compared to 4.16 kernel. 
Stream, Linpack and NAS parallel benchmarks show upto 50% performance drop.

When running for example 20 stream processes in parallel, we see the following behavior:

* all processes are started at NODE #1
* memory is also allocated on NODE #1
* roughly half of the processes are moved to the NODE #0 very quickly. 
* however, memory is not moved to NODE #0 and stays allocated on NODE #1

As the result, half of the processes are running on NODE#0 with memory being still 
allocated on NODE#1. This leads to non-local memory accesses
on the high Remote-To-Local Memory Access Ratio on the numatop charts.  

So it seems that 4.17 is not doing a good job to move the memory to the right NUMA
node after the process has been moved.

----8<----

The above is an excerpt from performance testing on 4.16 and 4.17 kernels.

For now I'm merely making sure the problem is reported.

Thank you.

Best regards,
Jakub Racek

             reply	other threads:[~2018-06-06 12:27 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-06-06 12:27 Jakub Racek [this message]
2018-06-06 12:34 ` [4.17 regression] Performance drop on kernel-4.17 visible on Stream, Linpack and NAS parallel benchmarks Rafael J. Wysocki
2018-06-06 12:44   ` Rafael J. Wysocki
2018-06-06 12:50   ` Jakub Racek
2018-06-06 12:56     ` Rafael J. Wysocki
2018-06-07 11:07 ` [4.17 regression] " Michal Hocko
2018-06-07 11:19   ` Jakub Raček
2018-06-07 11:56     ` Jirka Hladky
2018-06-07 12:39 ` Mel Gorman
     [not found]   ` <CAE4VaGBAZ0HCy-M2rC3ce9ePOBhE6H-LDVBuJDJMNFf40j70Aw@mail.gmail.com>
2018-06-08  7:40     ` Mel Gorman
     [not found]       ` <CAE4VaGAgC7vDwaa-9AzJYst9hdQ5KbnrBUnk_mfp=NeTEe5dAQ@mail.gmail.com>
2018-06-08  9:24         ` Mel Gorman
     [not found]           ` <CAE4VaGATk3_Hr_2Wh44BZvXDc06A=rxUZXRFj+D=Xwh2x1YOyg@mail.gmail.com>
2018-06-08 11:15             ` Mel Gorman
     [not found] <CAE4VaGBRFBM-uZEE=DdUzQkcNmpnUHdjK-7hgEeywmG8bvOOgw@mail.gmail.com>
2018-06-11 14:11 ` Mel Gorman
     [not found]   ` <CAE4VaGCMS2pXfPVSnMbudexv_m5wRCTuBKA5ijh2x==11uQg9g@mail.gmail.com>
2018-06-14  8:36     ` Mel Gorman
     [not found]       ` <CAE4VaGCzB99es_TpAaYvtjX8fqzFA=7HX-ezqgO6FaEB5if4zg@mail.gmail.com>
2018-06-15 11:25         ` Mel Gorman
     [not found]           ` <CAE4VaGBtasbDBoZ-c5R-AY++Y1BXgjrE7DwN0zOt113xmV95xw@mail.gmail.com>
2018-06-15 13:52             ` Mel Gorman
     [not found]               ` <CAE4VaGAdXNYXMUn4eQgMqQtLKfp6-YHMa1NUSpL-L078oX7C-w@mail.gmail.com>
     [not found]                 ` <CAE4VaGBeTpxd1phR4rVAjqOXuLgLWPtVMPoRSOcG3HXfWDF=8w@mail.gmail.com>
2018-06-19 15:18                   ` Mel Gorman
     [not found]                     ` <CAE4VaGAPOfy0RtQehKoe+443C1GRrJXCveBFgcAZ1nChVavp1g@mail.gmail.com>
     [not found]                       ` <CAE4VaGBMeL82SJK53gtcWkor-9eXeLX6VP9juw=FW=BOyp+hMA@mail.gmail.com>
2018-06-21  9:23                         ` Mel Gorman
     [not found]                           ` <CAE4VaGCQV+cS-vhdLyMwzftbB-xBHPt4Y4chg_0ykLHTE9cRfw@mail.gmail.com>
     [not found]                             ` <CAE4VaGDHcZbnDpJ+FiQLfA1DRftY0j_GJSnh3FDRi34OztVH6Q@mail.gmail.com>
2018-06-27  8:49                               ` Mel Gorman
     [not found]                                 ` <CAE4VaGA9KzX05rdfw2PhEATLisV-NVMc9rOyjzSg-rX1rug9Dw@mail.gmail.com>
     [not found]                                   ` <CABuKy6MUNX85PBVchz_hqXy+FxXU2x0U9ZEZB13rVSLGpWOWvQ@mail.gmail.com>
     [not found]                                     ` <CAE4VaGD12BLS_kk=pRwgTKL8YOU63Nowwa42cEdZObQ=P1MFnA@mail.gmail.com>
     [not found]                                       ` <CAE4VaGArxDYHzg8G203yKjgkuw3mULFSw8yCYbCcqvAUSUxy+A@mail.gmail.com>
2018-07-17 10:03                                         ` Mel Gorman
     [not found]                                           ` <CAE4VaGA_L1AEj+Un0oQEEqZp_jgaFLk+Z=vNoad08oXnU2T1nw@mail.gmail.com>
2018-09-03 15:07                                             ` Jirka Hladky
2018-09-04  9:00                                               ` Mel Gorman
2018-09-04 10:07                                                 ` Jirka Hladky
2018-09-06  8:16                                                   ` Jirka Hladky
2018-09-06 12:58                                                     ` Mel Gorman
2018-09-07  8:09                                                       ` Jirka Hladky
2018-09-14 16:50                                                         ` Jirka Hladky

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