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
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 ? ?n mie., 24 aug. 2016 la 18:13, <m.roth at 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 at centos.org > https://lists.centos.org/mailman/listinfo/centos >-- Laurentiu Soica