Non-alphanumeric names

[hakavlad]

Example of output for some non-alphanumeric names:

янв 23 05:24:15 PC earlyoom[18493]: Low memory! At or below SIGKILL limits (mem: 1 %, swap: 1 %)
янв 23 05:24:15 PC earlyoom[18493]: mem avail:  200 of 13855 MiB ( 1 %), swap free:    0 of    0 MiB ( 0 %)
янв 23 05:24:15 PC earlyoom[18493]: [90B blob data]
янв 23 05:28:15 PC earlyoom[18493]: mem avail: 9861 of 13855 MiB (71 %), swap free:    0 of    0 MiB ( 0 %)

This strange behavior should be documented and explained.
What is [90B blob data]?

[hakavlad]

And how --prefer and --avoid works with non-alphanumeric names?

[hakavlad]

Examples of cmdlines that was handled incorrectly: ./ЙЦУКЕНГШЩ, ./ячсмитьб, ./1ああああああああ1.

[hakavlad]

With debug:

янв 23 06:02:47 PC earlyoom[19296]: pid 19296: badness   0 vm_rss   1860 earlyoom
янв 23 06:02:47 PC earlyoom[19296]: pid 19297: badness   0 vm_rss   3780 sudo
янв 23 06:02:47 PC earlyoom[19296]: pid 19298: badness   0 vm_rss   5340 journalctl
янв 23 06:02:47 PC earlyoom[19296]: [53B blob data]
янв 23 06:02:47 PC earlyoom[19296]:     ^ new victim (higher badness)
янв 23 06:02:47 PC earlyoom[19296]: [90B blob data]
янв 23 06:02:47 PC earlyoom[19296]: selecting victim and sending signal took 8.008 ms
янв 23 06:02:47 PC earlyoom[19296]: adaptive sleep time: 100 ms
янв 23 06:02:47 PC earlyoom[19296]: adaptive sleep time: 461 ms

[hakavlad]

Killing process '...' with signal 9, pid: 19368, badness: 702, VmRSS: 9714 MiB is not displayed.

[rfjakob]

How do you view the log file? Can you try journalctl -a ?

[hakavlad]

How do you view the log file?

sudo journalctl -eu earlyoom
or realtime view:
sudo journalctl -fu earlyoom

[hakavlad]

Output in terminal:

mem avail: 8297 of 13855 MiB (59 %), swap free:    0 of    0 MiB ( 0 %)
mem avail: 5708 of 13855 MiB (41 %), swap free:    0 of    0 MiB ( 0 %)
mem avail: 2796 of 13855 MiB (20 %), swap free:    0 of    0 MiB ( 0 %)
Low Memory! At or below SIGTERM limits (mem: 10 %, swap: 10 %)
mem avail: 1410 of 13855 MiB (10 %), swap free:    0 of    0 MiB ( 0 %)
Killing process 'ячсмить�' with signal 15, pid: 19504, badness: 605, VmRSS: 8367 MiB
mem avail: 9768 of 13855 MiB (70 %), swap free:    0 of    0 MiB ( 0 %)
mem avail: 9759 of 13855 MiB (70 %), swap free:    0 of    0 MiB ( 0 %)

[hakavlad]

journalctl -a:

янв 23 06:12:30 PC earlyoom[19296]: pid 19298: badness   0 vm_rss   5964 journalctl
янв 23 06:12:30 PC earlyoom[19296]: pid 19443: badness 704 vm_rss 9971980 ячсмить<D0>
янв 23 06:12:30 PC earlyoom[19296]:     ^ new victim (higher badness)
янв 23 06:12:30 PC earlyoom[19296]: Killing process 'ячсмить<D0>' with signal 9, pid: 19443, badness: 704, VmRSS: 9738 MiB
янв 23 06:12:30 PC earlyoom[19296]: selecting victim and sending signal took 7.948 ms
янв 23 06:12:30 PC earlyoom[19296]: adaptive sleep time: 100 ms
янв 23 06:12:30 PC earlyoom[19296]: adaptive sleep time: 438 ms
янв 23 06:12:31 PC earlyoom[19296]: adaptive sleep time: 1000 ms

[hakavlad]

In nohang I get

UnicodeDecodeError: 'utf-8' codec can't decode byte 0xd0 in position 20: invalid continuation byte

at

        with open('/proc/' + pid + '/status') as f:
            for line in f:

By the way, cmdline was handled correctly.

[hakavlad]

Short unicode names (like йцук) was handled correctly. This problem appears if len(name) > 15 bytes.

[hakavlad]

Journalctl output with blob data if a process with the Unicode name is in the process list (without earlyoom):

янв 23 16:46:58 PC kernel: [19734]  1000 19734   194620     2022     229       4        0             0 kate
янв 23 16:46:58 PC kernel: [20437]     0 20437    79344      424      57       3        0             0 packagekitd
янв 23 16:46:58 PC kernel: [21057]  1000 21057   231392     7771     259       4        0             0 dolphin
янв 23 16:46:58 PC kernel: [92B blob data]
янв 23 16:46:58 PC kernel: [24555]  1000 24555   787871   186037     857       6        0             0 firefox-esr
янв 23 16:46:58 PC kernel: [24697]  1000 24697   782208   190934     861       6        0             0 firefox-esr
янв 23 16:46:58 PC kernel: [25998]  1000 25998   651199    41884     388       6        0             0 Web Content
янв 23 16:46:58 PC kernel: [26856]  1000 26856   194620     2006     223       3        0             0 kate
янв 23 16:46:58 PC kernel: [27225]  1000 27225    49826      543      81       3        0             0 file.so
янв 23 16:46:58 PC kernel: [27233]  1000 27233   589991    24892     409       5        0             0 vlc
янв 23 16:46:58 PC kernel: [27443]  1000 27443   504571    32843     368       5        0             0 Web Content
янв 23 16:46:58 PC kernel: [27672]  1000 27672  2718374  2713392    5314      15        0             0 python3
янв 23 16:46:58 PC kernel: Out of memory: Kill process 27672 (python3) score 766 or sacrifice child
янв 23 16:46:58 PC kernel: Killed process 27672 (python3) total-vm:10873496kB, anon-rss:10853568kB, file-rss:0kB, shmem-rss:0kB
янв 23 16:47:32 PC sudo[27685]:     user : TTY=pts/0 ; PWD=/home/user ; USER=root ; COMMAND=/bin/journalctl -e
янв 23 16:47:32 PC sudo[27685]: pam_unix(sudo:session): session opened for user root by (uid=0)

May be it is a journalctl bug and it is not a bug for earlyoom. But output may be fixed if you remove bad bytes from names like this:

with open('/proc/' + pid + '/stat', 'rb') as f:
    line = f.read().decode('utf-8', 'ignore')

I don't know how to do it in C, but I have already solved this problem in nohang.

[rfjakob]

The problem is that the kernel truncates the name after 16 bytes, which may leave broken utf8 multibyte sequences. Fixed now in earlyoom via fix_truncated_utf8
(

earlyoom/msg.c

Line 128 in 8887f63

void fix_truncated_utf8(char *str) {

)