Per this suggestion [1] by hakavlad (Alexey Avramov), I did a single test with earlyoom, a user space service that's already packaged for Fedora. I have not yet tested nohang, also mentioned. I chose a configuration that has fairly consistently (>80%) resulted in a total hang for more than 30m. And the result with earlyoom is that while responsiveness in the GUI was still bad, the longest GUI freeze lasted ~8 minutes ending in oom which is certainly a lot better than a 30+ minute hang. It's entirely subjective, but my opinion is the system was legitimately lost within the 1st minute of hang, and a reasonable user can choose to give up at that point. Is this an improvement? Yes, the oom happens sooner, and maybe more testing will prove it's more predictable. Is it good enough? No. Should Fedora enable earlyoom in Fedora 32 Workstation? Maybe. Configuration: CPU i7-2820QM RAM: 7837M swap on ZRAM (lz4): 7836M (there is no other swap) BOOT_IMAGE=(hd5,gpt6)/boot/vmlinuz-5.3.0-0.rc6.git1.1.fc32.x86_64 root=UUID=72df6d5b-26d1-47ff-a9ab-33f6a0b2c4cf ro rootflags=subvol=root log_buf_len=4M systemd.debug-shell=1 printk.devkmsg=on slub_debug=FZPU Logs [2] [3] [4] all monotonic time, and screenshot [5]. The screenshot monotonic time equivalent is ~ [ 4890.404675] which coincides with GUI totally hung, and a sysrq+t issued via ssh. There's a lot going on including some i915 weirdness that I've been informed by upstream is swap related, but I don't know the significance of these kernel/gnome-shell page allocation failure complaints (they don't taint the kernel). But suffice to say there are questionable things happening well before the oom kill is issued. [1] https://pagure.io/fedora-workstation/issue/98#comment-594295 [2] Full journal https://drive.google.com/open?id=1nnZupWFnGfqu41aYs-u3UL8ir180YiL_ [3] dmesg only https://drive.google.com/open?id=1FNc7e-XuIiIAzSdBkOg98x9jgYEQQWbr [4] earlyoom messages only https://drive.google.com/open?id=1drd570PRbUiiSnCwoP26DMSgSo93SdAC [5] screenshot shows top and iotop at the time of heavy CPU, IO, memory and swap pressure https://drive.google.com/open?id=1unLv11HmHW3bYOJvlLSuZYSiv6gyw7L3 _______________________________________________ devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@xxxxxxxxxxxxxxxxxxxxxxx
