Re: [PATCH] x86/topology: Fallback to SMT level only once

2016-08-29 Thread Jirka Hladky
Hi Peter, yes, initially I have reported the issue to occur on Intel E5v3 CPU (that CPU does not have CoD) but it has turned to be a fluctuation of results. After repeating the test 10 times it has turned out that Intel E5v3 CPU is not affected. I'm sorry for that. I have then rerun the test on

Re: [PATCH] x86/topology: Fallback to SMT level only once

2016-08-29 Thread Jirka Hladky
Hi Peter, yes, initially I have reported the issue to occur on Intel E5v3 CPU (that CPU does not have CoD) but it has turned to be a fluctuation of results. After repeating the test 10 times it has turned out that Intel E5v3 CPU is not affected. I'm sorry for that. I have then rerun the test on

Re: [PATCH] x86/topology: Fallback to SMT level only once

2016-08-29 Thread Jiri Olsa
On Mon, Aug 29, 2016 at 12:40:47PM +0200, Peter Zijlstra wrote: > On Sun, Aug 28, 2016 at 08:19:46PM +0200, Jiri Olsa wrote: > > Jirka, Peter and Jean-Pierre reported performance drop on > > some cpus after making cpu offline and online again. > > > > The reason is the kernel logic that falls

Re: [PATCH] x86/topology: Fallback to SMT level only once

2016-08-29 Thread Jiri Olsa
On Mon, Aug 29, 2016 at 12:40:47PM +0200, Peter Zijlstra wrote: > On Sun, Aug 28, 2016 at 08:19:46PM +0200, Jiri Olsa wrote: > > Jirka, Peter and Jean-Pierre reported performance drop on > > some cpus after making cpu offline and online again. > > > > The reason is the kernel logic that falls

Re: [PATCH] x86/topology: Fallback to SMT level only once

2016-08-29 Thread Peter Zijlstra
On Sun, Aug 28, 2016 at 08:19:46PM +0200, Jiri Olsa wrote: > Jirka, Peter and Jean-Pierre reported performance drop on > some cpus after making cpu offline and online again. > > The reason is the kernel logic that falls back to SMT > level topology if more than one node is detected within > CPU

Re: [PATCH] x86/topology: Fallback to SMT level only once

2016-08-29 Thread Peter Zijlstra
On Sun, Aug 28, 2016 at 08:19:46PM +0200, Jiri Olsa wrote: > Jirka, Peter and Jean-Pierre reported performance drop on > some cpus after making cpu offline and online again. > > The reason is the kernel logic that falls back to SMT > level topology if more than one node is detected within > CPU

[PATCH] x86/topology: Fallback to SMT level only once

2016-08-28 Thread Jiri Olsa
Jirka, Peter and Jean-Pierre reported performance drop on some cpus after making cpu offline and online again. The reason is the kernel logic that falls back to SMT level topology if more than one node is detected within CPU package. During the system boot this logic cuts out the DIE topology

[PATCH] x86/topology: Fallback to SMT level only once

2016-08-28 Thread Jiri Olsa
Jirka, Peter and Jean-Pierre reported performance drop on some cpus after making cpu offline and online again. The reason is the kernel logic that falls back to SMT level topology if more than one node is detected within CPU package. During the system boot this logic cuts out the DIE topology