Bug 42607

Summary: AMD Bulldozer cache structure reported wrong
Product: Platform Specific/Hardware Reporter: Steffen Arntz (winrootkit)
Component: x86-64Assignee: platform_x86_64 (platform_x86_64)
Status: CLOSED CODE_FIX    
Severity: normal CC: alan, Brice.Goglin, florian, mightyiampresence
Priority: P1    
Hardware: All   
OS: Linux   
Kernel Version: 3.2 Subsystem:
Regression: No Bisected commit-id:

Description Steffen Arntz 2012-01-19 14:11:51 UTC 
1) /sys/devices/system/cpu/cpu*/cache/index2/shared_cpu_list contains a single processor number, there should be two of them there (both cores of the module)
2) I think the L1 instruction part is shared among the entire dual-core module as well, so same problem with /sys/devices/system/cpu/cpu*/cache/index1/shared_cpu_list
2) if the L1 data size is 64kB per core, then /sys/devices/system/cpu/cpu*/cache/index0/size should report 64KB instead of 16KB

It appeared to me looking at lstopos output:
https://svn.open-mpi.org/trac/hwloc/ticket/62

and they had a look at it and found the Kernel reporting things wrong.
Comment 1 Florian Mickler 2012-03-09 20:45:01 UTC 
A patch referencing this bug report has been merged in Linux v3.3-rc6:

commit 32c3233885eb10ac9cb9410f2f8cd64b8df2b2a1
Author: Andreas Herrmann <andreas.herrmann3@amd.com>
Date:   Wed Feb 8 20:52:29 2012 +0100

    x86/amd: Fix L1i and L2 cache sharing information for AMD family 15h processors