DTrace output on FreeBSD collected while building the kernel ("make
buildkernel") with the following short DTrace script running (note
that the default compiler on FreeBSD, clang, mmaps in the input files
so the C compiler is noticeably absent from the list of read
activity.)

dtrace -n 'syscall::read:return { @[execname] = quantize(arg0); @["TOTAL"] = quantize(arg0); }'
