http://qiita.com/yuku_t/items/2f5341e4aa635800a0a1
https://gist.github.com/hayajo/3950496
p=26690 while : do T1=$(cat /proc/$p/io | grep ^write_bytes | awk '{print $2}'); \ sleep 1; \ T2=$(cat /proc/$p/io | grep ^write_bytes | awk '{print $2}'); \ echo -n "$p " ; echo "$(expr \( $_T2 - $_T1 \) )" bytes ; \ done