Gecko [ www.jobworksschool.com ]

Name	Size	Permission	Date
lib	[ DIR ]	drwxr-xr-x	2025-11-05 21:34
argdist_example.txt	22.49 KB	-rw-r--r--	2023-12-08 15:36
bashreadline_example.txt	882 B	-rw-r--r--	2023-12-08 15:36
bindsnoop_example.txt	4.42 KB	-rw-r--r--	2023-12-08 15:36
biolatency_example.txt	23.46 KB	-rw-r--r--	2023-12-08 15:36
biolatpcts_example.txt	2.97 KB	-rw-r--r--	2023-12-08 15:36
biopattern_example.txt	1.37 KB	-rw-r--r--	2023-12-08 15:36
biosnoop_example.txt	3.47 KB	-rw-r--r--	2023-12-08 15:36
biotop_example.txt	9.11 KB	-rw-r--r--	2023-12-08 15:36
bitesize_example.txt	4.98 KB	-rw-r--r--	2023-12-08 15:36
bpflist_example.txt	2.13 KB	-rw-r--r--	2023-12-08 15:36
btrfsdist_example.txt	9.32 KB	-rw-r--r--	2023-12-08 15:36
btrfsslower_example.txt	6.65 KB	-rw-r--r--	2023-12-08 15:36
cachestat_example.txt	3.92 KB	-rw-r--r--	2023-12-08 15:36
cachetop_example.txt	3.83 KB	-rw-r--r--	2023-12-08 15:36
capable_example.txt	6.5 KB	-rw-r--r--	2023-12-08 15:36
cobjnew_example.txt	2.97 KB	-rw-r--r--	2023-12-08 15:36
compactsnoop_example.txt	9.92 KB	-rw-r--r--	2023-12-08 15:36
cpudist_example.txt	16.48 KB	-rw-r--r--	2023-12-08 15:36
cpuunclaimed_example.txt	15.2 KB	-rw-r--r--	2023-12-08 15:36
criticalstat_example.txt	4.81 KB	-rw-r--r--	2023-12-08 15:36
cthreads_example.txt	2.08 KB	-rw-r--r--	2023-12-08 15:36
dbslower_example.txt	3.89 KB	-rw-r--r--	2023-12-08 15:36
dbstat_example.txt	6.5 KB	-rw-r--r--	2023-12-08 15:36
dcsnoop_example.txt	4.27 KB	-rw-r--r--	2023-12-08 15:36
dcstat_example.txt	3.26 KB	-rw-r--r--	2023-12-08 15:36
deadlock_example.txt	16.25 KB	-rw-r--r--	2023-12-08 15:36
dirtop_example.txt	4.98 KB	-rw-r--r--	2023-12-08 15:36
drsnoop_example.txt	5 KB	-rw-r--r--	2023-12-08 15:36
execsnoop_example.txt	6.64 KB	-rw-r--r--	2023-12-08 15:36
exitsnoop_example.txt	6.22 KB	-rw-r--r--	2023-12-08 15:36
ext4dist_example.txt	8.78 KB	-rw-r--r--	2023-12-08 15:36
ext4slower_example.txt	11.07 KB	-rw-r--r--	2023-12-08 15:36
filegone_example.txt	743 B	-rw-r--r--	2023-12-08 15:36
filelife_example.txt	2.04 KB	-rw-r--r--	2023-12-08 15:36
fileslower_example.txt	5.58 KB	-rw-r--r--	2023-12-08 15:36
filetop_example.txt	6.8 KB	-rw-r--r--	2023-12-08 15:36
funccount_example.txt	13.29 KB	-rw-r--r--	2023-12-08 15:36
funcinterval_example.txt	15.28 KB	-rw-r--r--	2023-12-08 15:36
funclatency_example.txt	20.98 KB	-rw-r--r--	2023-12-08 15:36
funcslower_example.txt	6.63 KB	-rw-r--r--	2023-12-08 15:36
gethostlatency_example.txt	1.29 KB	-rw-r--r--	2023-12-08 15:36
hardirqs_example.txt	37.05 KB	-rw-r--r--	2023-12-08 15:36
inject_example.txt	6.67 KB	-rw-r--r--	2023-12-08 15:36
javacalls_example.txt	3.91 KB	-rw-r--r--	2023-12-08 15:36
javaflow_example.txt	5.88 KB	-rw-r--r--	2023-12-08 15:36
javagc_example.txt	3.78 KB	-rw-r--r--	2023-12-08 15:36
javaobjnew_example.txt	2.97 KB	-rw-r--r--	2023-12-08 15:36
javastat_example.txt	2.98 KB	-rw-r--r--	2023-12-08 15:36
javathreads_example.txt	2.08 KB	-rw-r--r--	2023-12-08 15:36
killsnoop_example.txt	1.31 KB	-rw-r--r--	2023-12-08 15:36
klockstat_example.txt	8.34 KB	-rw-r--r--	2023-12-08 15:36
kvmexit_example.txt	11.63 KB	-rw-r--r--	2023-12-08 15:36
llcstat_example.txt	3.24 KB	-rw-r--r--	2023-12-08 15:36
mdflush_example.txt	1.74 KB	-rw-r--r--	2023-12-08 15:36
memleak_example.txt	10.02 KB	-rw-r--r--	2023-12-08 15:36
mountsnoop_example.txt	1.45 KB	-rw-r--r--	2023-12-08 15:36
mysqld_qslower_example.txt	2.3 KB	-rw-r--r--	2023-12-08 15:36
netqtop_example.txt	12.2 KB	-rw-r--r--	2023-12-08 15:36
nfsdist_example.txt	8.31 KB	-rw-r--r--	2023-12-08 15:36
nfsslower_example.txt	7.68 KB	-rw-r--r--	2023-12-08 15:36
nodegc_example.txt	3.78 KB	-rw-r--r--	2023-12-08 15:36
nodestat_example.txt	2.98 KB	-rw-r--r--	2023-12-08 15:36
offcputime_example.txt	19.2 KB	-rw-r--r--	2023-12-08 15:36
offwaketime_example.txt	37.36 KB	-rw-r--r--	2023-12-08 15:36
oomkill_example.txt	1.88 KB	-rw-r--r--	2023-12-08 15:36
opensnoop_example.txt	10.33 KB	-rw-r--r--	2023-12-08 15:36
perlcalls_example.txt	3.91 KB	-rw-r--r--	2023-12-08 15:36
perlflow_example.txt	5.88 KB	-rw-r--r--	2023-12-08 15:36
perlstat_example.txt	2.98 KB	-rw-r--r--	2023-12-08 15:36
phpcalls_example.txt	3.91 KB	-rw-r--r--	2023-12-08 15:36
phpflow_example.txt	5.88 KB	-rw-r--r--	2023-12-08 15:36
phpstat_example.txt	2.98 KB	-rw-r--r--	2023-12-08 15:36
pidpersec_example.txt	677 B	-rw-r--r--	2023-12-08 15:36
ppchcalls_example.txt	6.93 KB	-rw-r--r--	2023-12-08 15:36
profile_example.txt	31.08 KB	-rw-r--r--	2023-12-08 15:36
pythoncalls_example.txt	3.91 KB	-rw-r--r--	2023-12-08 15:36
pythonflow_example.txt	5.88 KB	-rw-r--r--	2023-12-08 15:36
pythongc_example.txt	3.78 KB	-rw-r--r--	2023-12-08 15:36
pythonstat_example.txt	2.98 KB	-rw-r--r--	2023-12-08 15:36
rdmaucma_example.txt	1.94 KB	-rw-r--r--	2023-12-08 15:36
readahead_example.txt	3.17 KB	-rw-r--r--	2023-12-08 15:36
reset-trace_example.txt	9.15 KB	-rw-r--r--	2023-12-08 15:36
rubycalls_example.txt	3.91 KB	-rw-r--r--	2023-12-08 15:36
rubyflow_example.txt	5.88 KB	-rw-r--r--	2023-12-08 15:36
rubygc_example.txt	3.78 KB	-rw-r--r--	2023-12-08 15:36
rubyobjnew_example.txt	2.97 KB	-rw-r--r--	2023-12-08 15:36
rubystat_example.txt	2.98 KB	-rw-r--r--	2023-12-08 15:36
runqlat_example.txt	31.3 KB	-rw-r--r--	2023-12-08 15:36
runqlen_example.txt	11.85 KB	-rw-r--r--	2023-12-08 15:36
runqslower_example.txt	2.13 KB	-rw-r--r--	2023-12-08 15:36
shmsnoop_example.txt	2.73 KB	-rw-r--r--	2023-12-08 15:36
slabratetop_example.txt	5.22 KB	-rw-r--r--	2023-12-08 15:36
sofdsnoop_example.txt	3.14 KB	-rw-r--r--	2023-12-08 15:36
softirqs_example.txt	11.02 KB	-rw-r--r--	2023-12-08 15:36
solisten_example.txt	2.3 KB	-rw-r--r--	2023-12-08 15:36
sslsniff_example.txt	6.74 KB	-rw-r--r--	2023-12-08 15:36
stackcount_example.txt	21.45 KB	-rw-r--r--	2023-12-08 15:36
statsnoop_example.txt	3.02 KB	-rw-r--r--	2023-12-08 15:36
swapin.txt	2.57 KB	-rw-r--r--	2023-12-08 15:36
swapin_example.txt	1.39 KB	-rw-r--r--	2023-12-08 15:36
syncsnoop_example.txt	387 B	-rw-r--r--	2023-12-08 15:36
syscount_example.txt	6.27 KB	-rw-r--r--	2023-12-08 15:36
tclcalls_example.txt	3.91 KB	-rw-r--r--	2023-12-08 15:36
tclflow_example.txt	5.88 KB	-rw-r--r--	2023-12-08 15:36
tclobjnew_example.txt	2.97 KB	-rw-r--r--	2023-12-08 15:36
tclstat_example.txt	2.98 KB	-rw-r--r--	2023-12-08 15:36
tcpaccept_example.txt	2.76 KB	-rw-r--r--	2023-12-08 15:36
tcpcong_example.txt	33.31 KB	-rw-r--r--	2023-12-08 15:36
tcpconnect_example.txt	6.27 KB	-rw-r--r--	2023-12-08 15:36
tcpconnlat_example.txt	2.55 KB	-rw-r--r--	2023-12-08 15:36
tcpdrop_example.txt	1.95 KB	-rw-r--r--	2023-12-08 15:36
tcplife_example.txt	6.83 KB	-rw-r--r--	2023-12-08 15:36
tcpretrans_example.txt	3.85 KB	-rw-r--r--	2023-12-08 15:36
tcprtt_example.txt	9.83 KB	-rw-r--r--	2023-12-08 15:36
tcpstates_example.txt	2.84 KB	-rw-r--r--	2023-12-08 15:36
tcpsubnet_example.txt	5.37 KB	-rw-r--r--	2023-12-08 15:36
tcpsynbl_example.txt	1.15 KB	-rw-r--r--	2023-12-08 15:36
tcptop_example.txt	5.75 KB	-rw-r--r--	2023-12-08 15:36
tcptracer_example.txt	1.98 KB	-rw-r--r--	2023-12-08 15:36
threadsnoop_example.txt	1.07 KB	-rw-r--r--	2023-12-08 15:36
tplist_example.txt	4.4 KB	-rw-r--r--	2023-12-08 15:36
trace_example.txt	21.62 KB	-rw-r--r--	2023-12-08 15:36
ttysnoop_example.txt	3.24 KB	-rw-r--r--	2023-12-08 15:36
vfscount_example.txt	2.17 KB	-rw-r--r--	2023-12-08 15:36
vfsstat_example.txt	1.66 KB	-rw-r--r--	2023-12-08 15:36
virtiostat_example.txt	2.62 KB	-rw-r--r--	2023-12-08 15:36
wakeuptime_example.txt	33.25 KB	-rw-r--r--	2023-12-08 15:36
xfsdist_example.txt	6.77 KB	-rw-r--r--	2023-12-08 15:36
xfsslower_example.txt	6.91 KB	-rw-r--r--	2023-12-08 15:36
zfsdist_example.txt	9.52 KB	-rw-r--r--	2023-12-08 15:36
zfsslower_example.txt	7.37 KB	-rw-r--r--	2023-12-08 15:36

Rename

Demonstrations of oomkill, the Linux eBPF/bcc version.

oomkill is a simple program that traces the Linux out-of-memory (OOM) killer,
and shows basic details on one line per OOM kill:

# ./oomkill
Tracing oom_kill_process()... Ctrl-C to end.
21:03:39 Triggered by PID 3297 ("ntpd"), OOM kill of PID 22516 ("perl"), 3850642 pages, loadavg: 0.99 0.39 0.30 3/282 22724
21:03:48 Triggered by PID 22517 ("perl"), OOM kill of PID 22517 ("perl"), 3850642 pages, loadavg: 0.99 0.41 0.30 2/282 22932

The first line shows that PID 22516, with process name "perl", was OOM killed
when it reached 3850642 pages (usually 4 Kbytes per page). This OOM kill
happened to be triggered by PID 3297, process name "ntpd", doing some memory
allocation.

The system log (dmesg) shows pages of details and system context about an OOM
kill. What it currently lacks, however, is context on how the system had been
changing over time. I've seen OOM kills where I wanted to know if the system
was at steady state at the time, or if there had been a recent increase in
workload that triggered the OOM event. oomkill provides some context: at the
end of the line is the load average information from /proc/loadavg. For both
of the oomkills here, we can see that the system was getting busier at the
time (a higher 1 minute "average" of 0.99, compared to the 15 minute "average"
of 0.30).

oomkill can also be the basis of other tools and customizations. For example,
you can edit it to include other task_struct details from the target PID at
the time of the OOM kill.

The following commands can be used to test this program, and invoke a memory
consuming process that exhausts system memory and is OOM killed:

sysctl -w vm.overcommit_memory=1              # always overcommit
perl -e 'while (1) { $a .= "A" x 1024; }'     # eat all memory

WARNING: This exhausts system memory after disabling some overcommit checks.
Only test in a lab environment.