Linux KERNEL TESTING signaltest

ABOUT Signal(IPC)

Signals are a limited form of inter-process communication (IPC), typically used in Unix, Unix-like, and other POSIX-compliant operating systems. A signal is an asynchronous notification sent to a process or to a specific thread within the same process in order to notify it of an event that occurred. Signals originated in 1970s Bell Labs Unix and have been more recently specified in the POSIX standard.

When a signal is sent, the operating system interrupts the target process' normal flow of execution to deliver the signal. Execution can be interrupted during any non-atomic instruction. If the process has previously registered a signal handler, that routine is executed. Otherwise, the default signal handler is executed.

TYPICAL COMMANDLINE SESSION
[bash]
$sudo ./signaltest –help
signaltest V 0.85
Usage:
signaltest <options>

-b USEC –breaktrace=USEC send break trace command when latency > USEC
-l LOOPS –loops=LOOPS number of loops: default=0(endless)
-p PRIO –prio=PRIO priority of highest prio thread
-q –quiet print only a summary on exit
-t NUM –threads=NUM number of threads: default=2
-m –mlockall lock current and future memory allocations
-v –verbose output values on stdout for statistics
format: n:c:v n=tasknum c=count v=value in us

$sudo ./signaltest -v -t 10 -l 10
0: 0: 0
0: 1: 118
0: 2: 91
0: 3: 83
0: 4: 80
0: 5: 78
0: 6: 78
0: 7: 80
0: 8: 78
0: 9: 79
$

[/bash]
LINK
https://en.wikipedia.org/wiki/Signal_(IPC)
https://www.ibm.com/developerworks/community/blogs/aimsupport/entry/Finding_the_source_of_signals_on_Linux_with_strace_auditd_or_Systemtap?lang=en

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