/proc/profile - kernel profiling

/proc/profile (since Linux 2.4)

This file is present only if the kernel was booted with the profile=1 command-line option. It exposes kernel profiling information in a binary format for use by readprofile(1). Writing (e.g., an empty string) to this file resets the profiling counters; on some architectures, writing a binary integer "profiling multiplier" of size sizeof(int) sets the profiling interrupt frequency.

proc(5)