Hi,
After switching to the 2.6.32-573.22.1.el6.x86_64 kernel (CentOS 6) a few weeks ago I have noticed that my servers are now reporting a much higher idle load.
The servers are being monitored with Zabbix, and there is a clear difference between the older kernel 2.6.32-573.12.1 and the newer 2.6.32-573.12.1.
I can see the problem on both physical and virtual servers.
You can see the Load Average chart here from one of our servers: http://imgur.com/U1eihMX
The server is pretty much idle all the time, but the load average increased from 0.001 to 0.300 when updated to the new kernel.
Is anyone else seeing the same behavior?
Best Regards, Johnny Carlsen ________________________________ CONFIDENTIAL AND PRIVILEGED: This e-mail and associated content is subject to the disclaimer statement found at http://aware.co.th/emaildisclaimer/rev1-0.php.
On 04/08/2016 06:50 AM, Johnny Carlsen wrote:
Hi,
After switching to the 2.6.32-573.22.1.el6.x86_64 kernel (CentOS 6) a few weeks ago I have noticed that my servers are now reporting a much higher idle load.
The servers are being monitored with Zabbix, and there is a clear difference between the older kernel 2.6.32-573.12.1 and the newer 2.6.32-573.12.1.
I can see the problem on both physical and virtual servers.
You can see the Load Average chart here from one of our servers: http://imgur.com/U1eihMX
The server is pretty much idle all the time, but the load average increased from 0.001 to 0.300 when updated to the new kernel.
Is anyone else seeing the same behavior?
This is one of the fixes listed on the errata page:
"Due to prematurely decremented calc_load_task, the calculated load average was off by up to the number of CPUs in the machine. As a consequence, job scheduling worked improperly causing a drop in the system performance. This update keeps the delta of the CPU going into NO_HZ idle separately, and folds the pending idle delta into the global active countwhile correctly aging the averages for the idle-duration when leaving NO_HZ mode. Now, job scheduling works correctly, ensuring balanced CPU load. (BZ#1300349)"
From: https://rhn.redhat.com/errata/RHSA-2016-0494.html
No idea if that is impacting the load shown on your machine .. maybe someone has some ideas.
On Fri, Apr 8, 2016 at 6:32 AM, Johnny Hughes johnny@centos.org wrote:
On 04/08/2016 06:50 AM, Johnny Carlsen wrote:
Hi,
After switching to the 2.6.32-573.22.1.el6.x86_64 kernel (CentOS 6) a
few weeks ago I have noticed that my servers are now reporting a much higher idle load.
The servers are being monitored with Zabbix, and there is a clear
difference between the older kernel 2.6.32-573.12.1 and the newer 2.6.32-573.12.1.
I can see the problem on both physical and virtual servers.
You can see the Load Average chart here from one of our servers: http://imgur.com/U1eihMX
The server is pretty much idle all the time, but the load average
increased from 0.001 to 0.300 when updated to the new kernel.
Is anyone else seeing the same behavior?
This is one of the fixes listed on the errata page:
"Due to prematurely decremented calc_load_task, the calculated load (snip)"
From: https://rhn.redhat.com/errata/RHSA-2016-0494.html
No idea if that is impacting the load shown on your machine .. maybe someone has some ideas.
An RHEL user is reporting what seems to be the same issue:
https://access.redhat.com/discussions/2247501
Akemi
This is one of the fixes listed on the errata page:
"Due to prematurely decremented calc_load_task, the calculated load (snip)"
From: https://rhn.redhat.com/errata/RHSA-2016-0494.html
No idea if that is impacting the load shown on your machine .. maybe someone has some ideas.
An RHEL user is reporting what seems to be the same issue:
https://access.redhat.com/discussions/2247501
Thanks, it is nice to see that others are experiencing this too and that it is already reported upstream.
Regards, Johnny ________________________________ CONFIDENTIAL AND PRIVILEGED: This e-mail and associated content is subject to the disclaimer statement found at http://aware.co.th/emaildisclaimer/rev1-0.php.
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Akemi Yagi -
Johnny Carlsen -
Johnny Hughes