Bug 42607 - AMD Bulldozer cache structure reported wrong
AMD Bulldozer cache structure reported wrong
Status: CLOSED CODE_FIX
Product: Platform Specific/Hardware
Classification: Unclassified
Component: x86-64
All Linux
: P1 normal
Assigned To: platform_x86_64@kernel-bugs.osdl.org
:
Depends on:
Blocks:
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Reported: 2012-01-19 14:11 UTC by Steffen Arntz
Modified: 2012-06-13 15:13 UTC (History)
4 users (show)

See Also:
Kernel Version: 3.2
Tree: Mainline
Regression: No


Attachments

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

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