Monitor device state change(detection etc):
udevadm monitor
Example ouput:
monitor will print the received events for:
UDEV - the event which udev sends out after rule processing
KERNEL - the kernel uevent
KERNEL[1200800.676000] add /devices/pci0000:00/0000:00:19.0/usb1/1-3 (usb)
KERNEL[1200800.671000] bind /devices/pci0000:00/0000:00:19.0/usb1/1-3/1-3:1.0 (usb)
KERNEL[1200801.677000] change /devices/pci0000:00/0000:00:19.0/usb1/1-3/1-3:1.0/host0/target0:0:0/0:0:0:0 (scsi)
...
Query device attributes from udev database:
udevadm info /dev/sdb1
Get a filename which corresponds to the inode in /proc/locks:
sudo find -L /proc/1146/fd -maxdepth 1 -inum 1625 -print -exec readlink {} \;
lslocks - list local system locks
Really really useful and interesting stuff for profiling:
/sys/kernel/debug/tracing/events/
Monitor all hardware interrupts:
sudo perf trace -e hw_interrupts.received
Latency info(not a default tool) - LatencyTOP
Instantly crash the system:
echo c > /proc/sysrq-trigger
This tunable takes a value in the range [0, 100] with a default value of 20. This tunable determines how aggressively compaction is done in the background.
sudo sysctl -a | grep compaction_proactiveness
Kill any process with a style:
sudo modprobe hwpoison-inject
sysctl -w vm.memory_failure_early_kill=1
git clone [email protected]:dwks/pagemap.git
cd pagemap
make
pidof watch # 10144
sudo cat /proc/10144/maps # get a stack range 7ffc8da82000-7ffc8dabc000
sudo ./pagemap 10144 0x7ffc8da82000 0x7ffc8dabc000
# get first non-zero PFN - 35f848
sudo echo 0x35f848 > /sys/kernel/debug/hwpoison/corrupt-pfnEnforce seccomp policy without writing any code:
systemd-run --user --pty --same-dir --wait --collect --service-type=exec --property="SystemCallFilter=~uname" uname -a