This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed- focal' to 'verification-done-focal'. If the problem still exists, change the tag 'verification-needed-focal' to 'verification-failed-focal'.
If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you! ** Tags added: verification-needed-focal -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1881096 Title: [UBUNTU 20.04] Deflate counters reported by lscpumf are not valid or available with perf Status in Ubuntu on IBM z Systems: Fix Committed Status in linux package in Ubuntu: Fix Committed 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] * d68d5d51dc898895b4e15bea52e5668ca9e76180 d68d5d51dc898895b "s390/cpum_cf: Add new extended counters for IBM z15" [Test Case] * Requires the fix/patch of the perf tool, as mentioned in the bug, too. * 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] * This requires a patch to be included into the perf itself, too - please see bug description for more details. * Since this patch is upstream in kernel 5.7 it will automatically land in groovy. __________ ---Problem Description--- ubuntu 20.04: perf on z15: some counters reported with lscpumf are not usable with perf stat -e ---uname output--- Linux ubu204 5.4.0-26-generic #30-Ubuntu SMP Mon Apr 20 16:57:22 UTC 2020 s390x s390x s390x GNU/Linux Machine Type = z15 8561 ---Steps to Reproduce--- lscpumf -c gives a list of available counters, but a few of them are not usable: DFLT_ACCESS,DFLT_CYCLES,DFLT_CC,DFLT_CCERROR perf list is also not offering these counters. A solution will be a backport to 20.04, and tried to made available for next SRU , code needed before 06-12. Addl Info from Dev: I have downloaded the following repository https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal and checked out branch master-next. Both patches appended apply without warning and the compilation showed no error. For the perf tool: e7950166e40271c02 perf vendor events s390: Add new deflate counters for IBM z15 For the s390 kernel d68d5d51dc898895b s390/cpum_cf: Add new extended counters for IBM z15 All accepted for kernel 5.7 rc1 Please include both patches into Ubuntu 20.04 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1881096/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
