奇怪的apache process state - BBS

請問一下，

最近在FreeBSD 7 (ctm到 src-7.0131.gz)跑Apache 2.2.8
一直遇到奇怪的apache process狀態，top狀態如下

last pid: 42862; load averages: 0.00, 0.00, 0.00 up 0+15:39:35 09:33:38
186 processes: 1 running, 185 sleeping
CPU states: 0.0% user, 0.0% nice, 0.0% system, 0.0% interrupt, 100% idle
Mem: 479M Active, 2050M Inact, 343M Wired, 428K Cache, 214M Buf, 20G Free
Swap: 16G Total, 16G Free

PID USERNAME THR PRI NICE SIZE RES STATE C TIME WCPU COMMAND
39618 www 27 44 0 280M 98M ucond 2 18:29 0.00% httpd
39628 www 27 44 0 277M 98272K ucond 1 5:30 0.00% httpd
39676 www 27 44 0 296M 106M ucond 2 3:39 0.00% httpd
39678 www 27 44 0 287M 98M ucond 2 0:25 0.00% httpd
42280 www 27 4 0 267M 84832K accept 0 0:09 0.00% httpd
39567 www 26 44 0 282M 92760K umtxn 7 0:04 0.00% httpd

目前觀察是STATE出現umtxn，apache就死了，直接connection refused :<
不知道有人有遇到相同狀況嗎?
另外，用top看的STATE那欄位的各種狀態，要怎麼man呢?
man了ps,top都查不到ucond，umtxn是代表甚麼意思:<


Thanks in advance!



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