> Date: Sun, 12 Jan 2020 11:40:23 +0100
> From: Klemens Nanni <[email protected]>
>
> On Sat, Jan 04, 2020 at 09:27:30PM +0100, Klemens Nanni wrote:
> > CPU strides provide means to effectively bind guests to certain specific
> > phsyical cores by overallocating virtual CPUs (hardware threads) such
> > that the sum of virtual CPUs and strides yields an integer multiple of
> > the CPU dependent threads-per-core factor, e.g. on T2 based machines
> > each CPU has 8 cores and each core has 8 threads. this makes for n times
> > virtual CPUs to be managed in ldom.conf(5).
> >
> > Diff below slightly extends the given example and tries to further
> > clarify what strides do. The example should match a T5120 machine for
> > example which features 1 T2+ CPU.
> >
> > It hopefully makes it clearer how "vcpu"s correspond to hardware threads
> > not physical CPU cores.
> >
> > Feedback? OK?
> Ping.
>
> How do others understand/read the stride parts? Does this diff make it
> any clearer?
This diff doesn't make it clearer.
> Index: ldom.conf.5
> ===================================================================
> RCS file: /cvs/src/usr.sbin/ldomctl/ldom.conf.5,v
> retrieving revision 1.9
> diff -u -p -r1.9 ldom.conf.5
> --- ldom.conf.5 3 Dec 2019 21:07:03 -0000 1.9
> +++ ldom.conf.5 12 Jan 2020 10:37:17 -0000
> @@ -78,11 +78,11 @@ Configure the MTU of the interface.
> .El
> .El
> .Sh EXAMPLES
> -Define a domain with 12 virtual cores, 4GB memory, two file based virtual
> disks
> -and one virtual network interface:
> +Define a domain with 12 virtual cores and 4 additionally allocated cores,
> +4GB memory, two file based virtual disks and one virtual network interface:
> .Bd -literal -offset indent
> domain "puffy" {
> - vcpu 12
> + vcpu 12:4
> memory 4G
> vdisk "/home/puffy/vdisk0"
> vdisk "/home/puffy/vdisk1"
> @@ -101,8 +101,10 @@ domain "salmah" {
> }
> .Ed
> .Pp
> -On a machine with 32 cores and 64GB physical memory, this leaves 12 cores and
> -58GB memory to the primary domain.
> +On a machine with 1 CPU comprising 8 cores with 8 threads each and 64GB
> physical
> +memory, this leaves 40 cores and 58GB memory to the primary domain.
> +.Dq puffy
> +will be assigned 16 threads of which 4 are not being used.
> .Sh SEE ALSO
> .Xr eeprom 8 ,
> .Xr ldomctl 8 ,
>
>
