Bug 153058 - gdm-binary process comsumes 70% CPU after changing tls->tls.disable
Summary: gdm-binary process comsumes 70% CPU after changing tls->tls.disable
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: None
Product: Fedora
Classification: Fedora
Component: xen
Version: 4
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Rik van Riel
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2005-04-01 05:47 UTC by Fei Fei
Modified: 2007-11-30 22:11 UTC (History)
0 users

Fixed In Version:
Clone Of:
Environment:
Last Closed: 2005-04-04 09:57:52 UTC
Type: ---
Embargoed:


Attachments (Terms of Use)
readprofile output (14.32 KB, text/plain)
2005-04-01 06:37 UTC, Fei Fei
no flags Details

Description Fei Fei 2005-04-01 05:47:00 UTC
Description of problem:
The gdm-binary process comsumes 70% CPU after changing tls->tls.disable. When
TLS is enabled again, gdm-binary acts normally.

Version-Release number of selected component (if applicable):
kernel-xen0-devel-2.6.11-1.1177_FC4
kernel-xenU-devel-2.6.11-1.1177_FC4
kernel-xen0-2.6.11-1.1177_FC4
kernel-xenU-2.6.11-1.1177_FC4
xen-2-20050308


How reproducible:
everytime.


Steps to Reproduce:
1.choose grub ento xen VMM and Domain0
2.#mv /lib/tls /lib/tls.disable; reboot
3.#top
4.#mv /lib/tls.disable /lib/tls; reboot
5.#top
  
Actual results:
gdm-binary process consumes 70%+ CPU when tls is disabled.

Expected results:
gdm-binary will get < 10% CPU 

Additional info:

Comment 1 Rik van Riel 2005-04-01 05:53:10 UTC
Firstly, there is no need to move /lib/tls out of the way - TLS emulation can be
slow at times, but it does work correctly now that Xen uses segment flipping.

Secondly, could you take a look where the CPU time is being spent?

Is it spent in user space, or in kernel space?  If the latter, could you boot
with 'profile=2' and use readprofile to figure out where the cpu time is being
spent ?

Comment 2 Fei Fei 2005-04-01 06:37:45 UTC
Created attachment 112572 [details]
readprofile output

readprofile output

Comment 3 Fei Fei 2005-04-01 06:39:50 UTC
The output of "top" shows 79% in sys and 20% in user.
The output of readprofile with "profile=2" is attached.

Comment 4 Fei Fei 2005-04-04 09:57:52 UTC
From statement of bug #151367, it seems it's a common bug but not a xen specific
one. I updated the latest gdm package it's ok now.


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