apache 频繁挂掉，什么原因？
apache 2.2.3的版本，晚上发现频繁的自动停止服务，启动后最慢2分钟左右，最快10多秒就自动停止服务了，查看日志(error_log)发现有下列日志，请问是什么原因？前两天还正常.
[Tue Dec 19 22:44:14 2006] [alert] (11)Resource temporarily unavailable: setuid:
unable to change to uid: 2
[Tue Dec 19 22:44:14 2006] [alert] (11)Resource temporarily unavailable: setuid:
unable to change to uid: 2
[Tue Dec 19 22:44:14 2006] [alert] (11)Resource temporarily unavailable: setuid:
unable to change to uid: 2
[Tue Dec 19 22:44:14 2006] [alert] (11)Resource temporarily unavailable: setuid:
unable to change to uid: 2
[Tue Dec 19 22:44:14 2006] [alert] (11)Resource temporarily unavailable: setuid:
unable to change to uid: 2
[Tue Dec 19 22:44:14 2006] [alert] (11)Resource temporarily unavailable: setuid:
unable to change to uid: 2
[Tue Dec 19 22:44:14 2006] [alert] (11)Resource temporarily unavailable: setuid:
unable to change to uid: 2
[Tue Dec 19 22:44:14 2006] [alert] (11)Resource temporarily unavailable: setuid:
unable to change to uid: 2
[Tue Dec 19 22:44:14 2006] [alert] (11)Resource temporarily unavailable: setuid:
unable to change to uid: 2
[Tue Dec 19 22:44:14 2006] [alert] (11)Resource temporarily unavailable: setuid:
unable to change to uid: 2
[Tue Dec 19 22:44:14 2006] [alert] (11)Resource temporarily unavailable: setuid:
unable to change to uid: 2
[Tue Dec 19 22:44:14 2006] [alert] (11)Resource temporarily unavailable: setuid:
unable to change to uid: 2
[Tue Dec 19 22:44:14 2006] [alert] (11)Resource temporarily unavailable: setuid:
unable to change to uid: 2
[Tue Dec 19 22:44:14 2006] [alert] Child 9766 returned a Fatal error... Apache i
s exiting!
[Tue Dec 19 22:44:14 2006] [emerg] (43)Identifier removed: couldn't grab the acc
ept mutex
[Tue Dec 19 22:44:14 2006] [emerg] (43)Identifier removed: couldn't grab the acc
ept mutex
[Tue Dec 19 22:44:14 2006] [emerg] (43)Identifier removed: couldn't grab the acc
ept mutex
[Tue Dec 19 22:44:17 2006] [emerg] (22)Invalid argument: couldn't grab the accep
t mutex
[Tue Dec 19 22:44:17 2006] [emerg] (22)Invalid argument: couldn't grab the accep
t mutex
[Tue Dec 19 22:44:17 2006] [emerg] (22)Invalid argument: couldn't grab the accep
t mutex
[Tue Dec 19 22:44:18 2006] [emerg] (22)Invalid argument: couldn't grab the accep
t mutex
[Tue Dec 19 22:44:18 2006] [emerg] (22)Invalid argument: couldn't grab the accep
t mutex
[Tue Dec 19 22:44:18 2006] [emerg] (22)Invalid argument: couldn't grab the accep
t mutex
[Tue Dec 19 22:44:18 2006] [emerg] (22)Invalid argument: couldn't grab the accep
t mutex
[Tue Dec 19 22:44:18 2006] [emerg] (22)Invalid argument: couldn't grab the accep
t mutex
[Tue Dec 19 22:44:18 2006] [emerg] (22)Invalid argument: couldn't grab the accep
t mutex
[Tue Dec 19 22:44:18 2006] [emerg] (22)Invalid argument: couldn't grab the accep
t mutex
[Tue Dec 19 22:44:18 2006] [emerg] (22)Invalid argument: couldn't grab the accep
t mutex
[Tue Dec 19 22:44:18 2006] [emerg] (22)Invalid argument: couldn't grab the accep
t mutex
[Tue Dec 19 22:44:20 2006] [emerg] (22)Invalid argument: couldn't grab the accep
t mutex
[Tue Dec 19 22:44:20 2006] [emerg] (22)Invalid argument: couldn't grab the accep
t mutex
[Tue Dec 19 22:44:20 2006] [emerg] (22)Invalid argument: couldn't grab the accep
t mutex
[Tue Dec 19 22:44:20 2006] [emerg] (22)Invalid argument: couldn't grab the accep
t mutex
[Tue Dec 19 22:44:34 2006] [emerg] (22)Invalid argument: couldn't release the ac
cept mutex
[Tue Dec 19 22:44:37 2006] [warn] pid file /usr/local/apache2/logs/httpd.pid ove
rwritten -- Unclean shutdown of previous Apache run?
