[Bug 1873489] Re: lscpu cache information is incorrect with focal on arm 64-bit platform (ThunderX2)

2020-05-03 Thread Taihsiang Ho
Hi Mauricio, thank you for providing the information that I was not
aware of. It's very clear and helpful for me.

Because the ThunderX2 is unavailable for me currently, I verified the
output format with Focal on an arm d06 cpu, which is able to reproduce
the "issue" (my own host name "scobee"). It is exactly what you have
said.

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1873489

Title:
  lscpu cache information is incorrect with focal on arm 64-bit platform
  (ThunderX2)

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1873489/+subscriptions

-- 
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

[Bug 1873489] Re: lscpu cache information is incorrect with focal on arm 64-bit platform (ThunderX2)

2020-04-29 Thread Mauricio Faria de Oliveira
Hi Taihsiang,

Thanks for reporting this bug.

This is an upstream deliberate change in output format of caches in lscpu.
They introduced the '--caches' option to provide individual/total sizes.

It affects other architectures as well, not just arm64; e.g., amd64.

For example, on my laptop:

Bionic:

$ lscpu | grep cache
L1d cache:   32K
L1i cache:   32K
L2 cache:256K
L3 cache:3072K

Focal:

$ lscpu | grep cache
L1d cache:   64 KiB
L1i cache:   64 KiB
L2 cache:512 KiB
L3 cache:3 MiB

On Eoan and later you can use `lscpu --caches` to get all/individual
cache information.

Focal:

$ lscpu --caches
NAME ONE-SIZE ALL-SIZE WAYS TYPELEVEL
L1d   32K  64K8 Data1
L1i   32K  64K8 Instruction 1
L2   256K 512K4 Unified 2
L3 3M   3M   12 Unified 3

$ lscpu --caches=one-size
ONE-SIZE
 32K
 32K
256K
  3M

For documentation purposes, this is the PR requesting/discussing it [1],
and this is the patch changing it [2].

Since this has been an upstream decision (see PR comments and patch), I
guess it's unlikely they'd change it back (even though it broke the
previous output convention, as that has been mentioned/acknowledged in
the PR.)

This patch has been introduced on 2.34, so Eoan and later have this
format change.

Hope this helps,
Mauricio

[1] https://github.com/karelzak/util-linux/issues/663
[2] 
https://github.com/karelzak/util-linux/commit/e5f721132ec8b8c933a396d8dcb3efcb67854f13

** Bug watch added: github.com/karelzak/util-linux/issues #663
   https://github.com/karelzak/util-linux/issues/663

** Changed in: util-linux (Ubuntu)
   Status: New => Invalid

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1873489

Title:
  lscpu cache information is incorrect with focal on arm 64-bit platform
  (ThunderX2)

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1873489/+subscriptions

-- 
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs