Thx for the analysis and the sharing of the commit IDs for the two patches from kernel 5.2-rc3 in comment #19. Since you mentioned three patches in comment #18 I assume the 3rd one became obsolete?
With that I assume that: "perf record: Fix s390 missing module symbol and warning for non-root users" 6738028dd57df064b969d8392c943ef3b3ae705d and "perf machine: Read also the end of the kernel" ed9adb2035b5be5896d465b19040262be5f4a824 need to be applied to Disco, (Cosmic) and Bionic. They will automatically land in Eoan, since kernel 5.2 is Eoan's target kernel. Is it correct that: edeb0c90df3581b821a764052d185df985f8b8dc "perf tools: Stop fallbacking to kallsyms for vdso symbols lookup" does not need to be considered anymore (neither for cosmic nor for bionic)? -- 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/1828166 Title: perf top problem on z with Ubuntu 18.04 Status in Ubuntu on IBM z Systems: Triaged Status in linux package in Ubuntu: Fix Released Status in linux source package in Bionic: In Progress Status in linux source package in Cosmic: In Progress Bug description: SRU Justification: ================== [Impact] * The perf top tool hangs and shows error messages, like 'Not enough memory for annotating' [Fix] * edeb0c90df3581b821a764052d185df985f8b8dc edeb0c9 "perf tools: Stop fallbacking to kallsyms for vdso symbols lookup" [Test Case] * start a benchmark (mem_alloc, but it doesn't really matter what) * execute perf top in a second terminal * the output of perf top is correct * now stop the benchmark * and perf top shows an error message, like "Not enough memory for annotating '__irf_end' symbol!)" * and perf top can't be exited anymore [Regression Potential] * The regression potential can be considered as low since this happens only while using the perf top tool * and it is known that the commit (above) fixes the problem * and the fix is upstream since 4.19 [Other Info] * current disco and eoan kernels don't show that problem * bisecting result points to above commit * applies cleanly on cosmic, but has a little conflict on bionic (both master-next) _________________________ perf top hangs and shows error messages ---uname output--- Linux weather 4.15.0-46-generic #49-Ubuntu SMP Wed Feb 6 09:32:27 UTC 2019 s390x s390x s390x GNU/Linux ---Steps to Reproduce--- I start a benchmark (mem_alloc, but it really doesn't matter) and then issue perf top in a second terminal, the output from perf top is correct. Now I stop the benchmark: perf top shows a error message (Not enough memory for annotating '__irf_end' symbol!) and I can't quit from perf top anymore Following analyse took place: No problem with current kernel . Bi-Secting of perf tool took place and following commit was found: commit edeb0c90df3581b821a764052d185df985f8b8dc (HEAD, refs/bisect/bad) Author: Arnaldo Carvalho de Melo <a...@redhat.com> Date: Tue Oct 16 17:08:29 2018 -0300 perf tools: Stop fallbacking to kallsyms for vdso symbols lookup When you apply this patch the issue is gone, however it is contained in these versions: git tag --contains edeb0c90df3581b821 v4.19 v4.20 .... The level I was debugging was kernel 4.15 which does not contain this patch. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1828166/+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
