stress-ng adds more features

Since I last wrote about perf being added to stress-ng back in the end of May I have been busy in my spare time adding more features to stress-ng.

New stressors include:

• ptrace - traces a child process performing many simple system calls
• sigsuspend - sends SIGUSR1 signals to multiple children waiting on sigsuspend(2)
• sigpending - checks if SIGUSR1 signals are pending on a process that alternatively masks and umasks this signal
• mmapfork - rapidly spawn multiple child processes that try to allocate a chunk of free memory (and try to avoid swapping). Each process then uses  madvise(2) to hints before and after the memory is memset and then the child dies.
• quota - exercise various quotactl(2) Q_GET* commands
• sockpair - client/server socket I/O using socket pair and random sized I/O
• getrandom - exercise the new getrandom(2) system call
• numa -  migrates a memory mapped buffer and processes around NUMA modes, exercising migrate_pages(2), mbind(2) and move_pages(2).
• fcntl - exercises the fcntl(2) commands F_DUP, FDF_DUP, FD_CLOEXEC,  F_GETFD,  F_SETFD, F_GETFL, F_SETFL, F_GETOWN, F_SETOWN, F_GETOWN_EX, F_SETOWN_EX, F_GETSIG and F_SETSIG
• wcs - exercises libc wide character string functions (thanks to Christian Ehrhardt for this contribution).

 ..and I have added some improvements too:

• --yaml option to dump stats from --metrics, --perf, -tz into a YAML structured log.
• made the --aggressive option more aggressive by forcing more CPU migrations and context switches.

I have also added a thermal zone stats gathering option --tz to see how warm the machine is getting when running a test.  For example:

... where x86_pkg_temp is the CPU package temperature and acpitz are the two ACPI thermal zones on my desktop.

Stress-ng is being used to run stress test various kernels across a range of Ubuntu devices, such as phone, desktop and server.   Thrashing a system with hundreds of processes and a lot of low memory pressure is just one method of checking that kernel and daemons can handle a mix of demanding work loads.

stress-ng 0.04.12 is now available in Ubuntu Wily.   See the stress-ng project page for more details.