Bug 118330 - (SCHEDULER)with hyperthreading availible, and the kernel seeing two CPU's threads only ever run on CPU0
Summary: (SCHEDULER)with hyperthreading availible, and the kernel seeing two CPU's thr...
Keywords:
Status: CLOSED WONTFIX
Alias: None
Product: Fedora
Classification: Fedora
Component: kernel
Version: 1
Hardware: i686
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Ingo Molnar
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2004-03-15 16:47 UTC by Antony Carr
Modified: 2007-11-30 22:10 UTC (History)
1 user (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2004-09-29 20:11:51 UTC
Type: ---
Embargoed:


Attachments (Terms of Use)
/proc/cpuinfo output (950 bytes, text/plain)
2004-03-15 16:50 UTC, Antony Carr
no flags Details
dmesg output (14.95 KB, text/plain)
2004-03-15 16:51 UTC, Antony Carr
no flags Details
top, desg & cpuinfo output (17.06 KB, text/plain)
2004-03-20 03:00 UTC, Brent H.
no flags Details

Description Antony Carr 2004-03-15 16:47:46 UTC
From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; SunOS sun4u; en-US; rv:1.6)
Gecko/20040211 Firefox/0.8

Description of problem:
My P4 hyperthreading capable box correctly identifies two processors,
however no threads ever run on CPU1.

Version-Release number of selected component (if applicable):
kernel-2.4.22-1.2115.nptlsmp

How reproducible:
Always

Steps to Reproduce:
Install Fedora Core1 on a P4 Hyperthreading capable system, and run
something that is multi threaded, eg make -j2 xxxx

Actual Results:  CPU0 gets a healthy workload, however CPU1 gets no
threads executing on it.

Expected Results:  there should be some processes running on CPU1

Additional info:

Bad example - but if you watch top wharlst doing a make -j2 you will
see  something like:
CPU states:  cpu    user    nice  system    irq  softirq  iowait    idle
           total   90.6%    0.0%    8.2%   0.0%     0.0%    0.0%  100.8%
           cpu00   90.6%    0.0%    8.3%   0.0%     0.0%    0.0%    0.9%
           cpu01    0.0%    0.0%    0.0%   0.0%     0.0%    0.0%  100.0%

Comment 1 Antony Carr 2004-03-15 16:50:50 UTC
Created attachment 98537 [details]
/proc/cpuinfo output

Comment 2 Antony Carr 2004-03-15 16:51:39 UTC
Created attachment 98538 [details]
dmesg output

Comment 3 Dave Jones 2004-03-16 15:34:10 UTC
upgrade to the latest errata kernel (2174) and see if its repeatable
there.


Comment 4 Brent H. 2004-03-20 02:56:40 UTC
I have the same issue on a  Xeon 2.8ghz.  Cpu01 is 100% idle at all
times.  This happens on all of the following kernels:

kernel-smp-2.4.22-1.2149.nptl
kernel-smp-2.4.22-1.2166.nptl
kernel-smp-2.4.22-1.2115.nptl
kernel-smp-2.4.22-1.2174.nptl

Comment 5 Brent H. 2004-03-20 03:00:42 UTC
Created attachment 98704 [details]
top, desg & cpuinfo output

Comment 6 Brent H. 2004-03-20 07:02:56 UTC
Looks similar to
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=112597

Comment 7 Ingo Molnar 2004-08-18 11:33:18 UTC
does this still happen with recent kernels?

Comment 8 David Lawrence 2004-09-29 20:11:51 UTC
Thanks for the bug report. However, Red Hat no longer maintains this version of
the product. Please upgrade to the latest version and open a new bug if the problem
persists.

The Fedora Legacy project (http://fedoralegacy.org/) maintains some older releases, 
and if you believe this bug is interesting to them, please report the problem in
the bug tracker at: http://bugzilla.fedora.us/



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