** Changed in: linux (Ubuntu Focal)
       Status: In Progress => Fix Committed

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https://bugs.launchpad.net/bugs/1888551

Title:
  perf vendor events s390: Add new deflate counters for IBM z15

Status in Ubuntu on IBM z Systems:
  In Progress
Status in linux package in Ubuntu:
  In Progress
Status in linux source package in Focal:
  Fix Committed

Bug description:
  SRU Justification:
  ==================

  [Impact]

  * With perf from Ubuntu 20.04 on IBM z15 hardware, some counters
  reported with lscpumf are not usable with 'perf stat -e'.

  * 'lscpumf -c' provides a list of available counters, but the
  following are not usable: DFLT_ACCESS, DFLT_CYCLES, DFLT_CC,
  DFLT_CCERROR

  * 'perf list' is also not offering these counters.

  * On the kernel side this is fixed with the following upstream
  accepted commit:

  [Fix]

  * e7950166e40271c025e0eec348cdf5c63ac734fa "perf vendor events s390:
  Add new deflate counters for IBM z15"

  [Test Case]

  * Requires the fix/patch of the kernel
  (d68d5d51dc898895b4e15bea52e5668ca9e76180 "s390/cpum_cf: Add new
  extended counters for IBM z15")

  * An IBM z15 (or LinuxONE III) system with Ubuntu 20.04 installed in
  LPAR is needed where the counters are enabled in the activation
  profile.

  * Use 'perf list' to determine if the counters DFLT_ACCESS,
  DFLT_CYCLES, DFLT_CC, DFLT_CCERROR are listed

  * Use 'perf stat -e' to enable amd make use of these counters.

  [Regression Potential]

  * The regression can be considered as low, since:

  * it's architecture specific (s390x)

  * limited to IBM z15 hardware

  * and only additional (s390x) hardware counters are defined and added.

  [Other]

  * Since these patches are upstream in kernel 5.7 they will
  automatically land in groovy.

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