I tried if the two commits can be cleanly applied by cherry-picking them from bionic-master-next (and disco-master-next), and it looks good (with a little hick-up on disco).
I updated the SRU justification in the bug description and new test packages will be built soon (thx klebers). ** 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" + * b9c0a64901d5bdec6eafd38d1dc8fa0e2974fccb b9c0a64 "perf annotate: Fix + s390 gap between kernel end and module start" + + * 12a6d2940b5f02b4b9f71ce098e3bb02bc24a9ea 12a6d29 "perf record: Fix + module size on s390" [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 + * The regression potential can be considered as medium since this + happens only while using the perf top tool - * and it is known that the commit (above) fixes the problem + * and just 3 files are changed, and one of them is + arch/s390/util/machine.c - * and the fix is upstream since 4.19 + * but symbol and machine header in /tools/perf/util modified and several + loc added [Other Info] - * current disco and eoan kernels don't show that problem + * cherry-pick was possible to bionic-master-next and to disco-master- + next (but used '--strategy=recursive -X theirs' for disco) - * bisecting result points to above commit - - * applies cleanly on cosmic, but has a little conflict on bionic (both master-next) + * adding the patches to disco is to avoid regressions _________________________ 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. -- 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: Confirmed Status in linux source package in Bionic: In Progress Status in linux source package in Cosmic: Invalid Bug description: SRU Justification: ================== [Impact] * The perf top tool hangs and shows error messages, like 'Not enough memory for annotating' [Fix] * b9c0a64901d5bdec6eafd38d1dc8fa0e2974fccb b9c0a64 "perf annotate: Fix s390 gap between kernel end and module start" * 12a6d2940b5f02b4b9f71ce098e3bb02bc24a9ea 12a6d29 "perf record: Fix module size on s390" [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 medium since this happens only while using the perf top tool * and just 3 files are changed, and one of them is arch/s390/util/machine.c * but symbol and machine header in /tools/perf/util modified and several loc added [Other Info] * cherry-pick was possible to bionic-master-next and to disco-master- next (but used '--strategy=recursive -X theirs' for disco) * adding the patches to disco is to avoid regressions _________________________ 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. 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