The following diagnosis on osbench was done to better understand a article on April 4th, 2018.

Phoronix test suite describes osbench as

OSBench is a collection of micro-benchmarks for measuring operating system primitives like time to create threads/processes, launching programs, creating files, and memory allocation.

The OS bench github README gives the description below

Micro benchmarks
All benchmarks run their work for five seconds, and the fastest pass is reported.

Create 100 threads and wait for them to finish. Each thread does nothing (just return).

POSIX: pthread_create(), pthread_join()
WIN32: _beginthreadex(), WaitForSingleObject(), CloseHandle()

Create 100 processes and wait for them to finish. Each process does nothing (just exit).

Unix: fork(), waitpid()
WIN32: Not implemented (Windows lacks the corresponding functionality).
Launch 100 programs and wait for them to finish. Each program does nothing (just exit).

Unix: fork(), execlp(), waitpid()
WIN32: CreateProcess(), WaitForSingleObject(), CloseHandle()

Create 65,534 files, write 32 byts of data to each file, and then delete them.

fopen(), fwrite(), fclose(), remove()
NOTE: To measure filesystem/kernel performance rather than storage medium performance, consider using a RAM disk.

Allocate 1,000,000 small chunks of memory, and then free them. Each chunk is 4-128 bytes in size.

malloc(), free()