** Description changed: + 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 - + 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 + 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.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1828166 Title: perf top problem on z with Ubuntu 18.04 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1828166/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
