Bug 46001 - /proc/cpuinfo displays wrong core/siblings count for Intel Atom N270 CPU
Summary: /proc/cpuinfo displays wrong core/siblings count for Intel Atom N270 CPU
Status: NEW
Alias: None
Product: Platform Specific/Hardware
Classification: Unclassified
Component: i386 (show other bugs)
Hardware: All Linux
: P1 normal
Assignee: platform_i386
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2012-08-15 05:12 UTC by Evangelos Foutras
Modified: 2013-05-06 13:01 UTC (History)
4 users (show)

See Also:
Kernel Version: 3.5, 3.5.1, 3.7.2, 3.9
Subsystem:
Regression: Yes
Bisected commit-id:

Attachments
Diff of /proc/cpuinfo between Linux 3.4.8 and Linux 3.5.1 (1.53 KB, text/plain)
2012-08-15 05:41 UTC, Evangelos Foutras 		Details
Add an attachment (proposed patch, testcase, etc.)

Description Evangelos Foutras 2012-08-15 05:12:59 UTC 
/proc/cpuinfo on Linux 3.5 (and Linux 3.5.1) contains different values for cpu0's "siblings" and cpu1's "siblings" and "cpu cores", compared to the values seen on Linux 3.4.8 (and previous versions).

I came across a relevant-looking fix [1] but it's already included in Linux 3.5.x.

The CPU is an Intel Atom N270 [2] (1 core with Hyper-Threading).

[1] http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commit;h=ceb1cbac8eda66cf0f889def226b4e82f8ff857b
[2] http://ark.intel.com/products/36331/Intel-Atom-Processor-N270-%28512K-Cache-1_60-GHz-533-MHz-FSB%29
Comment 1 Evangelos Foutras 2012-08-15 05:41:09 UTC 
Created attachment 77751 [details]
Diff of /proc/cpuinfo between Linux 3.4.8 and Linux 3.5.1
Comment 2 Alfredo Amatriain 2012-09-22 09:28:52 UTC 
I'm experiencing the same bug with linux 3.5.3

Originally reported in the Arch bugtracker: 

https://bugs.archlinux.org/task/31606#comment99437
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