Bug 1177801 - Excessive cpu usage due to wrong timeout value
Summary: Excessive cpu usage due to wrong timeout value
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: None
Product: Red Hat Enterprise Virtualization Manager
Classification: Red Hat
Component: vdsm
Version: 3.5.0
Hardware: Unspecified
OS: Unspecified
unspecified
high
Target Milestone: ---
: 3.5.0
Assignee: Oved Ourfali
QA Contact: Jiri Belka
URL:
Whiteboard: infra
Depends On: 1177533
Blocks: 1177634
TreeView+ depends on / blocked
 
Reported: 2014-12-30 13:16 UTC by Oved Ourfali
Modified: 2016-02-10 19:23 UTC (History)
13 users (show)

Fixed In Version: vdsm-4.16.8.1-5.el6ev
Doc Type: Bug Fix
Doc Text:
Clone Of: 1177533
Environment:
Last Closed: 2015-02-16 13:37:53 UTC
oVirt Team: Infra
Target Upstream Version:
Embargoed:


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Description Oved Ourfali 2014-12-30 13:16:05 UTC
+++ This bug was initially created as a clone of Bug #1177533 +++

Description of problem:

The event loop is calculating timeout in seconds, but poll timeout
should be milliseconds. This causes poll to wait up to 30 milliseconds
instead of 30 seconds where there are no events to handle.

Profiling a system running one vm for 5 mintues show _process_events is
dominating the profile, taking 55% of cpu time.

Version-Release number of selected component (if applicable):
55df4a7f1c6cfefdc70b439d0d5a3f735f6bbd4b

How reproducible:
Always

Steps to Reproduce:
1. Run vdsm with very little load and profiling enabled

Actual results:
_process_events consuming more then 50% cpu time, called
millions of times per 5 minutes

Expected results:
_process_events should consume almost no cpu time

--- Additional comment from Nir Soffer on 2014-12-28 11:54:11 EST ---

Fixed in master, needs trivial backport.

Comment 1 Jiri Belka 2015-01-20 16:02:05 UTC
ok, vdsm-4.16.8.1-5.el6ev.x86_64

no high cpu found and _process_events was not present between highest 20 listed calls from profiling stats.


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