From: Daniel Veillard <veillard@redhat.com>
Date: Wed, 28 Sep 2011 01:59:43 +0000 (+0800)
Subject: virsh: update man page for cpu_shares parameter
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=0c92e1428f1f2a87933b1f5ef41f7fecaad696d2;p=libvirt.git

virsh: update man page for cpu_shares parameter

The man page suggest that the cpu_shares parameter of schedinfo
allows values 0-262144, but the kernel remaps values 0 and 1 to
the minimum 2, just document that behaviour:

[root@test ~]# cat /cgroup/cpu/libvirt/qemu/cpu.shares
1024
[root@test ~]# echo 0 > /cgroup/cpu/libvirt/qemu/cpu.shares
[root@test ~]# cat /cgroup/cpu/libvirt/qemu/cpu.shares
2
[root@test ~]# echo 1 > /cgroup/cpu/libvirt/qemu/cpu.shares
[root@test ~]# cat /cgroup/cpu/libvirt/qemu/cpu.shares
2
[root@test ~]#

* tools/virsh.pod: update description of the cpu_shares parameter
  to indicate the values 0 and 1 are automatically changed by the
  kernel to minimal value 2
---

diff --git a/tools/virsh.pod b/tools/virsh.pod
index c74478f259..1a9c3dceee 100644
--- a/tools/virsh.pod
+++ b/tools/virsh.pod
@@ -914,7 +914,8 @@ If I<--current> is specified, affect the current guest state.
 
 B<Note>: The cpu_shares parameter has a valid value range of 0-262144; Negative
 values are wrapped to positive, and larger values are capped at the maximum.
-Therefore, -1 is a useful shorthand for 262144.
+Therefore, -1 is a useful shorthand for 262144. On the Linux kernel, the
+values 0 and 1 are automatically converted to a minimal value of 2.
 
 B<Note>: The weight and cap parameters are defined only for the
 XEN_CREDIT scheduler and are now I<DEPRECATED>.