Bug 113592 - Hyperthreading does not show additional processors on PC-DL motherboard
Hyperthreading does not show additional processors on PC-DL motherboard
Product: Red Hat Linux
Classification: Retired
Component: kernel (Show other bugs)
All Linux
medium Severity medium
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Assigned To: Dave Jones
Brian Brock
Depends On:
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Reported: 2004-01-15 12:12 EST by Giorel
Modified: 2015-01-04 17:04 EST (History)
2 users (show)

See Also:
Fixed In Version:
Doc Type: Bug Fix
Doc Text:
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Clone Of:
Last Closed: 2004-07-12 17:02:26 EDT
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Regression: ---
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oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Attachments (Terms of Use)
sysreport bzip, should include dmesg entry (210.25 KB, text/plain)
2004-01-16 11:38 EST, Giorel
no flags Details

  None (edit)
Description Giorel 2004-01-15 12:12:21 EST
From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030922

Description of problem:
cat /proc/cpuinfo

only shows cpu0 and cpu1 when on smp
only shows cpu0 when not on smp

But this is dual xeon machine, and bootup says hyperthreading is enabled.

Tried noapic parameter...no effect

This is the motherboard:

no noht passed in kernel or /etc/grub.conf, ht just regular flag on
cpuinfo, everything in BIOS shows HT is enabled.

First it was 2.4.20-6smp, but now
2.4.20-24.9smp doesn't show improvement.

Realize errata for 9 will cease in April, but if it isn't too late
really like a possible fix.  Hasn't been tried on Enterprise 3?

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

How reproducible:

Steps to Reproduce:
1. enable Hyperthreading in BIOS
2. boot up into any linux 9 kernel
3. cat /proc/cpuinfo

Actual Results:  In non SMP kernel:  1 processor
In SMP kernel:  2 processors

Expected Results:  In non SMP kernel:  2 processor
In SMP kernel:  4 processors

Additional info:

Customer opened support case number 139877 with ASUS.
Comment 1 Dave Jones 2004-01-15 12:35:11 EST
The non-SMP kernel will only ever show 1 processor.
Comment 3 Dave Jones 2004-01-15 12:40:32 EST
duh, brain not in gear. I missed the fact that the SMP kernel was
missing the HT pairs. Hmm. Can we get dmesg output of the SMP kernel ?
Comment 4 Giorel 2004-01-16 11:38:03 EST
Created attachment 97058 [details]
sysreport bzip, should include dmesg entry

Comment 5 Giorel 2004-01-16 11:39:37 EST
please right click, file was supposed to be sysreport.bz2
Comment 6 Dave Jones 2004-07-12 17:02:26 EDT
end-of-life'd product

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