请问dm365在jffs2文件系统下，反复重启后，启动时间越来越慢是什么原因？

dear  大神们：
环境：DM365开发板 dvsdk_dm365_4_02_00_06，linux-2.6.32.17-psp03.01.01.39
在我反复上电重启dm365后，发现上电启动的时间越来越慢，主要延长的时间在Starting udev后，最开始只要在Starting udev后只要30秒；在重启了上百次后，竟然在Starting udev后需要60秒才完成。
不知道怎么回事？是否文件系统需要某些优化的地方呢？？谢谢

[   14.600000] __do_fb_ioctl__
[   14.620000]
[   14.620000] __do_fb_ioctl__argp is 0xbe800b84, var is 0x14,ret is 20
[   14.620000]
[   14.620000] __do_fb_ioctl__
[   14.640000]
[   14.640000] __do_fb_ioctl__argp is 0xbe800b84, var is 0x14,ret is 20
Starting udev
[   25.410000] udev: starting version 141
Remounting root file system...
Caching udev devnodes
Populating dev cachemv: cannot rename '/tmp/devices': No such file or directory
[   39.530000] NET: Registered protocol family 10
ALSA: Restoring mixer settings...
Configuring network interfaces... done.
Setting up IP spoofing protection: rp_filter.
/usr/***in/alsactl: load_state:1610: No soundcards found...
hwclock: can't open '/dev/misc/rtc': No such file or directory
INIT: Entering runlevel: 5
Starting system message bus: dbus.
Starting telnet daemon.
Starting syslogd/klogd: done
Starting thttpd.