Im running linux on my board and have to read info in /proc/[pid]/io. But it is not found.
$ dd if=/dev/zero of=/tmp/aa &
$ cat /proc/926/io
cat: /proc/926/io: No such file or directory
According to this, you need
CONFIG_TASKSTATS enabled in your kernel.
You can check your current kernel's config in various ways depending on distribution, but looking at
/boot/config-$(uname -r) works in Redhat flavors.
If you don't have that option configured, you'll need to recompile your kernel, or investigate why your distro doesn't enable it.