Bug 1296137
| Summary: | Exception when /dev/cpu_dma_latency is not available | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 7 | Reporter: | Frantisek Sumsal <fsumsal> |
| Component: | tuned | Assignee: | Jaroslav Škarvada <jskarvad> |
| Status: | CLOSED ERRATA | QA Contact: | Tereza Cerna <tcerna> |
| Severity: | low | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | 7.2 | CC: | jeder, jscotka, jskarvad, tcerna |
| Target Milestone: | rc | Keywords: | Patch |
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | tuned-2.7.0-1.el7 | Doc Type: | Bug Fix |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2016-11-04 07:26:58 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
Fixed in following upstream commit: https://git.fedorahosted.org/cgit/tuned.git/commit/?id=a2b0741eacdd65cd17db6eec68ef2dabb96bbba4 But consider adding support for PM_QoS into nspawn. I think that PM_QoS kernel hints from nspawned processes makes sense and that nspawned processes should be able to make such hints to kernel. ============================
Verified in:
tuned-2.7.1-2.el7.noarch
PASS
=============================
# mkdir testvm
# yum -y --nogpgcheck --installroot "$(pwd)/testvm" groupinstall minimal
# > testvm/var/log/messages && timeout 15 systemd-nspawn -bD testvm
# grep tuned testvm/var/log/messages
#
============================
Reproduced in:
tuned-2.5.1-4.el7.noarch
FAIL
=============================
# mkdir testvm
# yum -y --nogpgcheck --installroot "$(pwd)/testvm" groupinstall minimal
# > testvm/var/log/messages && timeout 15 systemd-nspawn -bD testvm
# grep tuned testvm/var/log/messages
Aug 18 09:49:51 testvm tuned: Exception in thread Thread-2:
Aug 18 09:49:51 testvm tuned: Traceback (most recent call last):
Aug 18 09:49:51 testvm tuned: File "/usr/lib64/python2.7/threading.py", line 811, in __bootstrap_inner
Aug 18 09:49:51 testvm tuned: self.run()
Aug 18 09:49:51 testvm tuned: File "/usr/lib64/python2.7/threading.py", line 764, in run
Aug 18 09:49:51 testvm tuned: self.__target(*self.__args, **self.__kwargs)
Aug 18 09:49:51 testvm tuned: File "/usr/lib/python2.7/site-packages/tuned/daemon/daemon.py", line 96, in _thread_code
Aug 18 09:49:51 testvm tuned: self._unit_manager.create(self._profile.units)
Aug 18 09:49:51 testvm tuned: File "/usr/lib/python2.7/site-packages/tuned/units/manager.py", line 62, in create
Aug 18 09:49:51 testvm tuned: plugin.initialize_instances()
Aug 18 09:49:51 testvm tuned: File "/usr/lib/python2.7/site-packages/tuned/plugins/base.py", line 109, in initialize_instances
Aug 18 09:49:51 testvm tuned: self._instance_init(instance)
Aug 18 09:49:51 testvm tuned: File "/usr/lib/python2.7/site-packages/tuned/plugins/plugin_cpu.py", line 99, in _instance_init
Aug 18 09:49:51 testvm tuned: self._cpu_latency_fd = os.open("/dev/cpu_dma_latency", os.O_WRONLY)
Aug 18 09:49:51 testvm tuned: OSError: [Errno 2] No such file or directory: '/dev/cpu_dma_latency'
#
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://rhn.redhat.com/errata/RHBA-2016-2479.html |
Description of problem: Containers created by systemd-nspawn do not create devices under /dev. This causes unhandled exception being thrown when /dev/cpu_dma_latency is not available: Jan 6 04:10:40 rhel7 systemd: Started Dynamic System Tuning Daemon. Jan 6 04:10:40 rhel7 tuned: Exception in thread Thread-2: Jan 6 04:10:40 rhel7 tuned: Traceback (most recent call last): Jan 6 04:10:40 rhel7 tuned: File "/usr/lib64/python2.7/threading.py", line 811, in __bootstrap_inner Jan 6 04:10:40 rhel7 tuned: self.run() Jan 6 04:10:40 rhel7 tuned: File "/usr/lib64/python2.7/threading.py", line 764, in run Jan 6 04:10:40 rhel7 tuned: self.__target(*self.__args, **self.__kwargs) Jan 6 04:10:40 rhel7 tuned: File "/usr/lib/python2.7/site-packages/tuned/daemon/daemon.py", line 96, in _thread_code Jan 6 04:10:40 rhel7 tuned: self._unit_manager.create(self._profile.units) Jan 6 04:10:40 rhel7 tuned: File "/usr/lib/python2.7/site-packages/tuned/units/manager.py", line 62, in create Jan 6 04:10:40 rhel7 tuned: plugin.initialize_instances() Jan 6 04:10:40 rhel7 tuned: File "/usr/lib/python2.7/site-packages/tuned/plugins/base.py", line 109, in initialize_instances Jan 6 04:10:40 rhel7 tuned: self._instance_init(instance) Jan 6 04:10:40 rhel7 tuned: File "/usr/lib/python2.7/site-packages/tuned/plugins/plugin_cpu.py", line 99, in _instance_init Jan 6 04:10:40 rhel7 tuned: self._cpu_latency_fd = os.open("/dev/cpu_dma_latency", os.O_WRONLY) Jan 6 04:10:40 rhel7 tuned: OSError: [Errno 2] No such file or directory: '/dev/cpu_dma_latency' However, this exception does not prevent machine from successfully starting. Version-Release number of selected component (if applicable): tuned-2.5.1-4.el7.noarch How reproducible: ## Create machine root & install packages from "minimal" group # mkdir testvm # yum -y --nogpgcheck --installroot "$(pwd)/testvm" groupinstall minimal ## Start test machine in another terminal/tmux/screen/... # screen -S nspawn systemd-nspawn -D testvm ## Grep tuned messages from test machine's /var/log/messages # grep tuned testvm/var/log/messages Actual results: Log shows an exception Expected results: tuned should report some kind of error message instead of unhandled exception