Public bug reported:
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.
** Affects: ubuntu-z-systems
Importance: Undecided
Status: In Progress
** Affects: linux (Ubuntu)
Importance: Undecided
Status: In Progress
** Affects: linux (Ubuntu Focal)
Importance: Undecided
Status: In Progress
** Also affects: linux (Ubuntu Focal)
Importance: Undecided
Status: New
** Changed in: linux (Ubuntu)
Status: New => In Progress
** Changed in: linux (Ubuntu Focal)
Status: New => In Progress
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https://bugs.launchpad.net/bugs/1888551
Title:
perf vendor events s390: Add new deflate counters for IBM z15
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