iotop, which we mentioned in the Exploring Yocto's tracing and profiling tools recipe, gives a general idea of the throughput on a system and a particular process.
iostat provides many more statistics regarding CPU usage and device utilization, but does not provide per process details. Finally,
blktrace, a GPLv2 licensed tool that monitors specific block devices' I/O at a low level, and can also compute I/O operations per second (IOPS).
Flash filesystems, even if they are presented to the user space as block devices, cannot be profiled with