unkillable apache httpd process

I have a problem with very recent -current. Apache2 when restarted via
/usr/local/etc/rc.d/apache2.sh, the httpd process becomes unkillable
and consumes quite some CPU cycles. Truss output

sigprocmask(0x3,0x280b8a30,0x0)                  = 0 (0x0)
sigprocmask(0x1,0x280b8a20,0xbfbfea20)           = 0 (0x0)
sigprocmask(0x3,0x280b8a30,0x0)                  = 0 (0x0)
sigprocmask(0x1,0x280b8a20,0xbfbfea20)           = 0 (0x0)
munmap(0x28578000,0x3000)                        = 0 (0x0)
sigprocmask(0x3,0x280b8a30,0x0)                  = 0 (0x0)
sigprocmask(0x1,0x280b8a20,0xbfbfea20)           = 0 (0x0)
sigprocmask(0x3,0x280b8a30,0x0)                  = 0 (0x0)
sigprocmask(0x1,0x280b8a20,0xbfbfea20)           = 0 (0x0)
munmap(0x28575000,0x3000)                        = 0 (0x0)
sigprocmask(0x3,0x280b8a30,0x0)                  = 0 (0x0)
munmap(0x2acee000,0x36120)                       = 0 (0x0)
close(3)                                         = 0 (0x0)
sigprocmask(0x1,0x0,0x80a611c)                   = 0 (0x0)
sigaction(SIGSEGV,{ SIG_DFL
0x0|ONSTACK|RESETHAND|NOCLDSTOP|NODEFER|NOCLDWAIT|SIGINFO ss_t },0x0)
= 0 (0x0)
sigaction(SIGSEGV,0x0,{ SIG_DFL
0x0|ONSTACK|RESETHAND|NOCLDSTOP|NODEFER|NOCLDWAIT|SIGINFO ss_t }) = 0
(0x0)
chdir("/usr/local")                              = 0 (0x0)
sigaction(SIGSEGV,{ SIG_DFL
0x0|ONSTACK|RESTART|RESETHAND|NOCLDSTOP|NODEFER|NOCLDWAIT ss_t },0x0)
= 0 (0x0)
getpid()                                         = 3622 (0xe26)
gettimeofday({1118216948 261226},0x0)            = 0 (0x0)

And it just gets stuck here and no further.

Jiawei
-- 
"Without the userland, the kernel is useless."
               --inspired by The Tao of Programming