Bug 512616

Summary:	squid wakes up the CPU when doing nothing
Product:	[Fedora] Fedora	Reporter:	Edwin ten Brink <fedora>
Component:	squid	Assignee:	Jiri Skala <jskala>
Status:	CLOSED NEXTRELEASE	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	low	Docs Contact:
Priority:	low
Version:	11	CC:	aglotov, drees76, henrik, jonathansteffan, jskala, mnagy
Target Milestone:	---	Keywords:	Upstream
Target Release:	---
Hardware:	All
OS:	Linux
URL:	http://www.squid-cache.org/bugs/show_bug.cgi?id=2011
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2009-07-22 07:17:24 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:
Bug Depends On:
Bug Blocks:	204948

Description Edwin ten Brink 2009-07-19 20:57:35 UTC

Description of problem:
Even without any connected clients, squid wakes up the CPU 100 times per second according to powertop. This does not seem necessary.


Version-Release number of selected component (if applicable):
$ rpm -q squid
squid-3.0.STABLE15-2.fc11.i586

Comment 1 David Rees 2009-07-20 18:00:26 UTC

Confirmed here, also affects F10 since it has the same version of squid.  Powertop reports this:

  12.3% (100.8)             squid : __mod_timer (process_timeout)

Stracing squid shows this going on 100 times a second:

epoll_wait(6, {}, 16384, 10)            = 0

Comment 2 Henrik Nordström 2009-07-20 19:56:58 UTC

Upstream are aware of this. Don't remember right now why it needed to do this other than that it's a workaround for a timing race and that it is not likely to be fixed in 3.0.

3.1 will behave better and will be available in F-12.

Comment 3 Edwin ten Brink 2009-07-21 19:38:10 UTC

(In reply to comment #2)
Found your original posting on squid-users mailing list in October 2008:
http://www.squid-cache.org/mail-archive/squid-users/200810/0158.html

(In reply to comment #1)
David, you seem to be right about the polling:
http://www.squid-cache.org/mail-archive/squid-users/200810/0148.html

Comment 4 Henrik Nordström 2009-07-21 20:02:26 UTC

The polling is a red herring (just an effect, not the cause), the issue is elsewhere, with the polling just plastering over it..

Linked to upstream bug report (closed).

Comment 5 Edwin ten Brink 2009-07-22 07:17:24 UTC

(In reply to comment #4)
> Linked to upstream bug report (closed).  

Ok, thanks. Let's close this one for now then with CLOSED - NEXTRELEASE (squid 3.1) as it appears to have been resolved indeed from the bug report at http://www.squid-cache.org/bugs/show_bug.cgi?id=2011