------- Comment From [email protected] 2019-07-16 08:52 EDT------- ran tests on m3545035. ubuntu 18.02 with latest updates. Recreated the problem first (Not enough memory for annotating '__irf_end' symbol! and a hang) with perf top and a workload. Installed provided packages, reboot to activate the new kernel:
root@m3545035:~# uname -a Linux m3545035 4.15.0-55-generic #60+lp1828166.2-Ubuntu SMP Fri Jul 12 12:49:26 UTC 2019 s390x s390x s390x GNU/Linux ran perf top again and could still recreate the problem: Not enough memory for annotating '__irf_end' symbol! and a hang. What I see: perf -v gives me 4.15.18 before and after linux-tools* install. Is that expected? The perf fixes do not come with a new version of perf? -- 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: Confirmed 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] * 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 <[email protected]> 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 : [email protected] Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
