Bug 1632854 - lscpu miss reports CPUs in a mixed cluster
Summary: lscpu miss reports CPUs in a mixed cluster
Keywords:
Status: NEW
Alias: None
Product: Fedora
Classification: Fedora
Component: util-linux
Version: 29
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: ---
Assignee: Karel Zak
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks: ARMTracker
TreeView+ depends on / blocked
 
Reported: 2018-09-25 17:21 UTC by Peter Robinson
Modified: 2018-09-25 17:21 UTC (History)
2 users (show)

Fixed In Version:
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Description Peter Robinson 2018-09-25 17:21:19 UTC
On a mixed cluster of CPUs like an ARM big.LITTLE SoC lscpu miss reports some of the details of the CPUs.

util-linux-2.32.1-1.fc29.aarch64

For example in the output below for a Rockchips 3399 we have a 6 core SoC with 2* Cortex-A72 and 4* Cortex-A53.

There's a couple of problems here, first is that it reports them all as A53s, second it sees it as 3 cores per "socket" where the break down is really 2 and 4.

A slightly different point is they're not really NUMA as the memory access is actually uniform, it's the CPUs themselves that aren't, although I'm not sure there's a proper term.

# lscpu
Architecture:        aarch64
Byte Order:          Little Endian
CPU(s):              6
On-line CPU(s) list: 0-5
Thread(s) per core:  1
Core(s) per socket:  3
Socket(s):           2
NUMA node(s):        1
Vendor ID:           ARM
Model:               4
Model name:          Cortex-A53
Stepping:            r0p4
BogoMIPS:            48.00
NUMA node0 CPU(s):   0-5
Flags:               fp asimd evtstrm aes pmull sha1 sha2 crc32 cpuid

Output of /proc/cpuinfo

processor       : 0
BogoMIPS        : 48.00
Features        : fp asimd evtstrm aes pmull sha1 sha2 crc32 cpuid
CPU implementer : 0x41
CPU architecture: 8
CPU variant     : 0x0
CPU part        : 0xd03
CPU revision    : 4

processor       : 1
BogoMIPS        : 48.00
Features        : fp asimd evtstrm aes pmull sha1 sha2 crc32 cpuid
CPU implementer : 0x41
CPU architecture: 8
CPU variant     : 0x0
CPU part        : 0xd03
CPU revision    : 4

processor       : 2
BogoMIPS        : 48.00
Features        : fp asimd evtstrm aes pmull sha1 sha2 crc32 cpuid
CPU implementer : 0x41
CPU architecture: 8
CPU variant     : 0x0
CPU part        : 0xd03
CPU revision    : 4

processor       : 3
BogoMIPS        : 48.00
Features        : fp asimd evtstrm aes pmull sha1 sha2 crc32 cpuid
CPU implementer : 0x41
CPU architecture: 8
CPU variant     : 0x0
CPU part        : 0xd03
CPU revision    : 4

processor       : 4
BogoMIPS        : 48.00
Features        : fp asimd evtstrm aes pmull sha1 sha2 crc32 cpuid
CPU implementer : 0x41
CPU architecture: 8
CPU variant     : 0x0
CPU part        : 0xd08
CPU revision    : 2

processor       : 5
BogoMIPS        : 48.00
Features        : fp asimd evtstrm aes pmull sha1 sha2 crc32 cpuid
CPU implementer : 0x41
CPU architecture: 8
CPU variant     : 0x0
CPU part        : 0xd08
CPU revision    : 2


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