Hello,
I have a CentOS 7 installation on baremetal with 2 CPUs, 10 cores each and HT enabled, 128 GB RAM.
The system has transparent hugetables enabled.
cat /sys/kernel/mm/transparent_hugepage/enabled [always] madvise never
The system reports anonymous hugepages pages usage and a size of hugepage of 2048Kb
cat /proc/meminfo |grep -i hugepages|grep AnonHugePages AnonHugePages: 35491840 kB
cat /proc/meminfo |grep -i hugepages|grep Hugepagesize Hugepagesize: 2048 kB
Anyway, checking the /proc/<pid>/smaps for each and every process on the system, the KernelPageSize reports 4K pages only.
for i in `ls /proc/|egrep '[0-9]+'` ; do grep 'KernelPageSize: ' /proc/$i/smaps; done|grep ' 4 kB'|wc -l 9758 for i in `ls /proc/|egrep '[0-9]+'` ; do grep 'KernelPageSize: ' /proc/$i/smaps; done|grep -v ' 4 kB'|wc -l 0
So it turns out that even is I have the THP enabled the pages still have a size of 4K .
Is there any extra setup in order to get 2MB pages ?
Thanks, Laurentiu
Laurentiu Soica wrote:
Hello,
I have a CentOS 7 installation on baremetal with 2 CPUs, 10 cores each and HT enabled, 128 GB RAM.
The system has transparent hugetables enabled.
<snip>
So it turns out that even is I have the THP enabled the pages still have a size of 4K .
Is there any extra setup in order to get 2MB pages ?
Be aware that with transparent huge pages enabled - I'm trying to remember what error you might get - it may be the "CPU blocked for x 120 seconds", as it deals with the page.
mark, back from vacation
So basically you're saying that this THP feature is broken for CentOS 7 ? The feature is enabled by default. Is there a thread opened on this issue ?
În mie., 24 aug. 2016 la 18:13, m.roth@5-cent.us a scris:
Laurentiu Soica wrote:
Hello,
I have a CentOS 7 installation on baremetal with 2 CPUs, 10 cores each
and
HT enabled, 128 GB RAM.
The system has transparent hugetables enabled.
<snip> > So it turns out that even is I have the THP enabled the pages still have a > size of 4K . > > Is there any extra setup in order to get 2MB pages ? > Be aware that with transparent huge pages enabled - I'm trying to remember what error you might get - it may be the "CPU blocked for x 120 seconds", as it deals with the page.
mark, back from vacation
CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
Laurentiu Soica wrote:
So basically you're saying that this THP feature is broken for CentOS 7 ? The feature is enabled by default. Is there a thread opened on this issue ?
I'm not sure it's broken, per se, but rather that something that I don't know may cause it to do this. It was certainly the case on 6.
mark
În mie., 24 aug. 2016 la 18:13, m.roth@5-cent.us a scris:
Laurentiu Soica wrote:
Hello,
I have a CentOS 7 installation on baremetal with 2 CPUs, 10 cores each
and
HT enabled, 128 GB RAM.
The system has transparent hugetables enabled.
<snip> > So it turns out that even is I have the THP enabled the pages still have a > size of 4K . > > Is there any extra setup in order to get 2MB pages ? > Be aware that with transparent huge pages enabled - I'm trying to remember what error you might get - it may be the "CPU blocked for x 120 seconds", as it deals with the page.
mark, back from vacation
CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
-- Laurentiu Soica _______________________________________________ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
On 8/24/2016 11:49 AM, Laurentiu Soica wrote:
So basically you're saying that this THP feature is broken for CentOS 7 ? The feature is enabled by default. Is there a thread opened on this issue ?
SQL database folks seem to say to turn it off regardless of the OS. I think the whole thing is broken by design.
-
John R Pierce -
Laurentiu Soica -
m.roth＠5-cent.us