On Mon, Sep 14, 2020 at 07:52:34PM +0200, Klemens Nanni wrote:
> On Wed, Sep 02, 2020 at 04:58:39PM +0200, Stefan Sperling wrote:
> > I would like to suggest an example for the EXAMPLES section which
> > illustrates how a suitable stride factor can be determined (divide the
> > number of desired "unused" cpus by the number of desired "used" cpus):
> We can do with an example, but to me yours does not read obvious enough.
>
> Also, `vcpu' denotes *virtual* CPUs inside domains, not CPUs on the
> machine, so "CPU" (without "V") reads off in your example and conflicts
> with the otherwise consistent mentions of "virtual CPUs" in this manual.
>
> Here's my last diff incl. an example which reads a tad clearer to me and
> is placed in the EXAMPLES section instead.
>
> Feedback? OK?
Ping. Diff reattached.
Index: ldom.conf.5
===================================================================
RCS file: /cvs/src/usr.sbin/ldomctl/ldom.conf.5,v
retrieving revision 1.13
diff -u -p -r1.13 ldom.conf.5
--- ldom.conf.5 21 Feb 2020 19:39:28 -0000 1.13
+++ ldom.conf.5 14 Sep 2020 17:51:39 -0000
@@ -38,8 +38,13 @@ If no configuration for the primary doma
all CPU and memory resources not used by any guest domains.
.It Ic vcpu Ar number Ns Op : Ns Ar stride
Declare the number of virtual CPUs assigned to a domain.
-Optionally a stride can be specified to allocate additional virtual CPUs
-but not assign them to a domain.
+Optionally a stride factor can be specified to allocate
+.Ar number
+virtual CPUs
+.Ar stride
+times but not assign more than
+.Ar number
+virtual CPUs to a domain, leaving the rest unassigned.
This can be used to distribute virtual CPUs over the available CPU cores.
.It Ic memory Ar bytes
Declare the amount of memory assigned to a domain, in bytes.
@@ -112,6 +117,20 @@ domain "salmah" {
.Pp
On a machine with 32 cores and 64GB physical memory, this leaves 12 cores and
58GB memory to the primary domain.
+.Pp
+Use
+.Ar stride
+factors to distribute virtual CPUs:
+.Bd -literal -offset indent
+domain "sun" {
+ vcpu 2:4
+ memory 4G
+ vdisk "/home/sun/vdisk0"
+}
+.Ed
+On a machine with eight threads per physical core, this allocates four strides
+of two virtual CPUs to the guest domain but only assigns one stride to it, i.e.
+make it occupy an entire physical core while running on only two threads.
.Sh SEE ALSO
.Xr eeprom 8 ,
.Xr ldomctl 8 ,
