http://d.hatena.ne.jp/flalin/20110417/1303025836
# d1=`cut -d. -f1 /proc/uptime`; dmesg | grep "^\[" | \ while read l; do l1=${l%%.*}; date --date "$[$d1 - ${l1:1}] seconds ago" +"[%Y/%m/%d %X]${l#*]}"; \ done | less
若干変えて投入、めも
https://blog.sleeplessbeastie.eu/2013/10/31/how-to-deal-with-dmesg-timestamps/
# dmesg -T