Bug 425791

Summary:	oprofiled can't be started more than once in guests
Product:	Red Hat Enterprise Linux 5	Reporter:	Markus Armbruster <armbru>
Component:	kernel-xen	Assignee:	Markus Armbruster <armbru>
Status:	CLOSED NOTABUG	QA Contact:	Martin Jenner <mjenner>
Severity:	low	Docs Contact:
Priority:	low
Version:	5.1	CC:	xen-maint
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2007-12-16 08:43:16 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Markus Armbruster 2007-12-15 18:19:06 UTC

Description of problem:
oprofiled can be started only once in an active Xenoprof domain.  Subsequent
attempts fail.

Version-Release number of selected component (if applicable):
Observed with oprofile-0.9.2-6.el5 and kernel-xen-2.6.18-58.el5 (both host and
guest).

How reproducible:
Always.

Steps to Reproduce:
0. Reboot host and guest (guest domid is 1)
1. In the host: opcontrol --start-daemon --no-vmlinux --xen=none --active-domains=1
2. In the guest: opcontrol --start --no-vmlinux --xen=none
3. In the host: opcontrol --start; opcontrol --stop; opcontrol --shutdown
4. In the guest: opcontrol --shutdown
5. (Optional, doesn't make a difference) in the host: opcontrol --start-daemon
6. In the guest: opcontrol --start-daemon

Actual results:
Steps 1.-5. succeed, step 6 fails: oprofiled refuses to start.  Hypervisor gripes:
(XEN) xenoprof: operation 8 failed for dom 2 (status : -1)

Expected results:
All steps succeed.  oprofiled runs in guest after step 6.  Hypervisor does not
gripe.

Comment 1 Markus Armbruster 2007-12-16 07:11:19 UTC

This appears *not* to be a regression: I downgraded Xen-related packages to GA
(kernel-xen-2.6.18-8.el5.x86_64.rpm python-virtinst-0.99.0-2.el5.noarch.rpm
libvirt-python-0.1.8-15.el5.x86_64.rpm virt-manager-0.2.6-7.el5.x86_64.rpm
libvirt-0.1.8-15.el5.x86_64.rpm xen-3.0.3-25.el5.x86_64.rpm
xen-libs-3.0.3-25.el5.x86_64.rpm), and can still reproduce the bug.

Comment 2 Markus Armbruster 2007-12-16 08:43:16 UTC

Things work with step 5
opcontrol --start-daemon --no-vmlinux --xen=none --active-domains=`virsh domid
rhel5pv`

The failing restart behavior is identical to what happens when you do step 2
before step 1, i.e. when you try to start the guest before the host.

Looks like things work as (mis-)designed.