Re: [hwloc-users] Selecting real cores vs HT cores

I'm not sure you're asking a well-formed question. When the BIOS is set to enable hyper threading, then several resources on the core are split when the machine is booted up (e.g., some of the queue depths for various processing units in the core are half the length that they are when

Re: [hwloc-users] Selecting real cores vs HT cores

Ok let me expand then. I don't have control over the bios. The testing I am doing resides on a cloud provider and from our testing it appears that it has HT enabled. It is ambiguous though to me what I see vs how they allocate on their hypervisor. I want to see if this has any effect. given

Re: [hwloc-users] Selecting real cores vs HT cores

Le 11/12/2014 21:51, Brock Palen a écrit : > When a system has HT enabled is one core presented the real one and one the > fake partner? Or is that not the case? > > If wanting to test behavior without messing with the bios how do I select > just the 'real cores' if this is the case? > > I

Re: [hwloc-users] Selecting real cores vs HT cores

On Dec 11, 2014, at 2:03 PM, Brice Goglin wrote: > By the way, if you can't in the BIOS, you may want to disable the > hyperthread in the kernel: > > for i in $(hwloc-calc --whole-system --po -I pu core:all.pu:0) ; do echo 0 > > /sys/devices/system/cpu/cpu$i/online ;

Re: [hwloc-users] Selecting real cores vs HT cores

Jeff Squyres (jsquyres), le Thu 11 Dec 2014 21:12:27 +, a écrit : > When the BIOS is set to enable hyper threading, then several resources on the > core are split when the machine is booted up (e.g., some of the queue depths > for various processing units in the core are half the length that

Re: [hwloc-users] Selecting real cores vs HT cores

Can someone post docs for this resource halving Squyres claims? I've never heard of this. Jeff On Thursday, December 11, 2014, Samuel Thibault wrote: > Jeff Squyres (jsquyres), le Thu 11 Dec 2014 21:12:27 +, a écrit : > > When the BIOS is set to enable hyper