timeout 30 sleep 100 parent pid is sleep don't like centos

[ningmingxiao]

docker run -d busybox sh -c "timeout 30 sleep 100"
root      170589  0.0  0.0 704520  5812 ?        Sl   14:18   0:00  \_ docker-containerd-shim 60f6f53effb48170c64c4ceb12ad995fef500cd0db1bc118b58bda7da77a1569 /var
root      170611  6.3  0.0   1320     4 ?        Ss   14:18   0:00      \_ sleep 100
root      170644  0.0  0.0   1320    44 ?        Ss   14:18   0:00          \_ timeout 30 sleep 100

docker run -d centos:7 sh -c "timeout 30 sleep 100"
root      170662  0.0  0.0 704776  5760 ?        Sl   14:19   0:00  \_ docker-containerd-shim 4fc91b318bcc1a3f5468df4edc708229d896c8b628aa735d1c77e771d1748715 /var
root      170683 10.0  0.0   8648   784 ?        Ss   14:19   0:00      \_ timeout 30 sleep 100
root      170721  0.0  0.0   4380   632 ?        S    14:19   0:00          \_ sleep 100