Unfortunately, when you are running a Xen kernel, the domain gets virtual CPUs - that information is not the same as for physical CPUs! If you want to confirm whether HT is enabled or not, try running a non-xen kernel. Or you can run xentop and compare the total number of "CPUs" it shows - which should be twice the number of physical cores in your system if you have HT enabled.
Morgan -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Jussi Silvennoinen Sent: Thursday, March 17, 2011 9:10 AM To: [email protected] Subject: Re: [rhelv5-list] Hyperthreading in rhel5 > I am trying to enable 'hyperthreading' on rhel5 86_64 bit servers. > > - kernel 2.6.18-194.8.1.el5xen > - The ht is enabled in bios, > > - [root@server ~]# dmesg |grep -i ht > Brought up 8 CPUs > Installing knfsd (copyright (C) 1996 > [email protected]). > Copyright (c) 1999-2008 LSI Corporation > > - cat /proc/cpuinfo |grep -i "ht" is showing the output of ht > > - Checked the /proc/cpuinfo > > processors : 8 > siblings : 1 > cpu cores : 1 > > - when I am executing top , getting 8 cpus running. > > In a document it was mentioned, if siblings and cpu cores are same then hyperthreading is not enabled. So for my case I will say that it is not enabled. > For rhel 5 onwareds there is no smp kernel found. > So how I will confirm for hyperthreading enabled. Well how many cpu-sockets do you have filled and what kind of cpu's? I've never found a faster way to figure this out than to see what HW is installed rather trying to understand it from the OS side. A single quadcore showing as 8 cpu's = HT alive and kicking. A single quadcore showing as 4 cpu's = no HT -- Jussi _______________________________________________ rhelv5-list mailing list [email protected] https://www.redhat.com/mailman/listinfo/rhelv5-list _______________________________________________ rhelv5-list mailing list [email protected] https://www.redhat.com/mailman/listinfo/rhelv5-list
