** Description changed:

- We're unable to run Turbostat on Turin 2P Volcano systems with core
- count greater than 400 on Ubuntu 22.04.  On Ubuntu 24.04 turbostat works
- fine.
+ BugLink: https://bugs.launchpad.net/bugs/2069961
  
- The following commit fixes the turbostat problem :
+ [Impact]
  
- 
https://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux.git/commit/?h=turbostat&id=3ac1d14d0583a2de75d49a5234d767e2590384dd
+ On large systems, e.g. with 512 cpus or more, turbostat fails to run due
+ to exceeding the rlimit for number of files. 512 cpus requires 1028 file
+ descriptors, but the current limit is 999.
+ 
+ $ lscpu
+ ...
+ CPU(s):                  512
+   On-line CPU(s) list:   0-511
+ ...
+ 
+ $ sudo turbostat
+ ...
+ turbostat: /sys/devices/system/cpu/cpu477/cpuidle/state0/usage: open failed: 
Too many open files
+ 
+ There is no workaround, apart from maybe using powerstat instead.
+ 
+ [Fix]
+ 
+ The fix is to increase the rlimit to increase the amount of file
+ descriptors that turbostat can open to 2^15, which should be plenty for
+ some time to come.
+ 
+ commit 3ac1d14d0583a2de75d49a5234d767e2590384dd
+ Author: Wyes Karny <wyes.ka...@amd.com>
+ Date:   Tue Oct 3 05:07:51 2023 +0000
+ Subject: tools/power turbostat: Increase the limit for fd opened
+ Link: 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3ac1d14d0583a2de75d49a5234d767e2590384dd
+ 
+ This landed in 6.9-rc2, and is a clean cherry pick to jammy and noble.
+ 
+ [Testcase]
+ 
+ Deploy a bare metal system with 512 or more cpus.
+ 
+ Install linux-tools:
+ 
+ $ sudo apt install linux-tools-$(uname -r)
+ 
+ Run turbostat:
+ 
+ $ sudo turbostat
+ ...
+ turbostat: /sys/devices/system/cpu/cpu477/cpuidle/state0/usage: open failed: 
Too many open files
+ 
+ There are test kernels available in the following ppa:
+ 
+ https://launchpad.net/~mruffell/+archive/ubuntu/sf388491-test
+ 
+ If you install them, you should be able to see normal turbostat output
+ for all cpus installed in the system.
+ 
+ [Where problems can occur]
+ 
+ We are simply increasing the rlimit for file descriptors that turbostat
+ can open. This should have no impact on any existing systems.
+ 
+ If a regression should occur, then turbostat functionality might not
+ work. Users could use powerstat instead as a workaround while things are
+ fixed.

** Summary changed:

- turbostat and powerstat not working on 22.04
+ turbostat fails with too many open files on large systems

** Description changed:

  BugLink: https://bugs.launchpad.net/bugs/2069961
  
  [Impact]
  
  On large systems, e.g. with 512 cpus or more, turbostat fails to run due
  to exceeding the rlimit for number of files. 512 cpus requires 1028 file
  descriptors, but the current limit is 999.
  
  $ lscpu
  ...
  CPU(s):                  512
-   On-line CPU(s) list:   0-511
+   On-line CPU(s) list:   0-511
  ...
  
  $ sudo turbostat
  ...
  turbostat: /sys/devices/system/cpu/cpu477/cpuidle/state0/usage: open failed: 
Too many open files
  
  There is no workaround, apart from maybe using powerstat instead.
  
  [Fix]
  
  The fix is to increase the rlimit to increase the amount of file
  descriptors that turbostat can open to 2^15, which should be plenty for
  some time to come.
  
  commit 3ac1d14d0583a2de75d49a5234d767e2590384dd
  Author: Wyes Karny <wyes.ka...@amd.com>
  Date:   Tue Oct 3 05:07:51 2023 +0000
  Subject: tools/power turbostat: Increase the limit for fd opened
  Link: 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3ac1d14d0583a2de75d49a5234d767e2590384dd
  
- This landed in 6.9-rc2, and is a clean cherry pick to jammy and noble.
+ This landed in 6.9-rc4, and is a clean cherry pick to jammy and noble.
  
  [Testcase]
  
  Deploy a bare metal system with 512 or more cpus.
  
  Install linux-tools:
  
  $ sudo apt install linux-tools-$(uname -r)
  
  Run turbostat:
  
  $ sudo turbostat
  ...
  turbostat: /sys/devices/system/cpu/cpu477/cpuidle/state0/usage: open failed: 
Too many open files
  
  There are test kernels available in the following ppa:
  
  https://launchpad.net/~mruffell/+archive/ubuntu/sf388491-test
  
  If you install them, you should be able to see normal turbostat output
  for all cpus installed in the system.
  
  [Where problems can occur]
  
  We are simply increasing the rlimit for file descriptors that turbostat
  can open. This should have no impact on any existing systems.
  
  If a regression should occur, then turbostat functionality might not
  work. Users could use powerstat instead as a workaround while things are
  fixed.

-- 
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https://bugs.launchpad.net/bugs/2069961

Title:
  turbostat fails with too many open files on large systems

Status in linux package in Ubuntu:
  Fix Released
Status in linux source package in Jammy:
  In Progress
Status in linux source package in Mantic:
  Won't Fix
Status in linux source package in Noble:
  In Progress

Bug description:
  BugLink: https://bugs.launchpad.net/bugs/2069961

  [Impact]

  On large systems, e.g. with 512 cpus or more, turbostat fails to run
  due to exceeding the rlimit for number of files. 512 cpus requires
  1028 file descriptors, but the current limit is 999.

  $ lscpu
  ...
  CPU(s):                  512
    On-line CPU(s) list:   0-511
  ...

  $ sudo turbostat
  ...
  turbostat: /sys/devices/system/cpu/cpu477/cpuidle/state0/usage: open failed: 
Too many open files

  There is no workaround, apart from maybe using powerstat instead.

  [Fix]

  The fix is to increase the rlimit to increase the amount of file
  descriptors that turbostat can open to 2^15, which should be plenty
  for some time to come.

  commit 3ac1d14d0583a2de75d49a5234d767e2590384dd
  Author: Wyes Karny <wyes.ka...@amd.com>
  Date:   Tue Oct 3 05:07:51 2023 +0000
  Subject: tools/power turbostat: Increase the limit for fd opened
  Link: 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3ac1d14d0583a2de75d49a5234d767e2590384dd

  This landed in 6.9-rc4, and is a clean cherry pick to jammy and noble.

  [Testcase]

  Deploy a bare metal system with 512 or more cpus.

  Install linux-tools:

  $ sudo apt install linux-tools-$(uname -r)

  Run turbostat:

  $ sudo turbostat
  ...
  turbostat: /sys/devices/system/cpu/cpu477/cpuidle/state0/usage: open failed: 
Too many open files

  There are test kernels available in the following ppa:

  https://launchpad.net/~mruffell/+archive/ubuntu/sf388491-test

  If you install them, you should be able to see normal turbostat output
  for all cpus installed in the system.

  [Where problems can occur]

  We are simply increasing the rlimit for file descriptors that
  turbostat can open. This should have no impact on any existing
  systems.

  If a regression should occur, then turbostat functionality might not
  work. Users could use powerstat instead as a workaround while things
  are fixed.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2069961/+subscriptions


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