Re: SCHEDULE and high load situations

Here is more information: (thanks robert for the help)

> Fatal trap 12: page fault while in kernel mode
> cpuid = 1; apic id = 01
> fault virtual address   = 0x14
> fault code              = supervisor write, page not present
> instruction pointer     = 0x8:0xc066a1c7
> stack pointer           = 0x10:0xe2626aa8
> frame pointer           = 0x10:0xe2626ab8
> code segment            = base 0x0, limit 0xfffff, type 0x1b
>                         = DPL 0, pres 1, def32 1, gran 1
> processor eflags        = interrupt enabled, resume, IOPL = 0
> current process         = 27897 (mimedefang)
>

db> where
unp_connect2(c4bb78a4,c39cc13c,0,0,0) at /usr/src/sys/kern/uipc_usrreq.c:892
unp_connect(c4bb78a4,c43d9380,c4dee9a0,c43d9380,80) at /usr/src/sys/kern/uipc_usrreq.c:865
uipc_connect(c4bb78a4,c43d9380,c4dee9a0) at /usr/src/sys/kern/uipc_usrreq.c:179
soconnect(c4bb78a4,c43d9380,c4dee9a0,0,bf1dad88) at /usr/src/sys/kern/uipc_socket.c:518
kern_connect(c4dee9a0,3,c43d9380,c43d9380,c3e958ac) at /usr/src/sys/kern/uipc_syscalls.c:477
connect(c4dee9a0,e2626d14,c,c4dee9a0,e2626d3c) at connect+0x42
syscall(2f,2f,2f,bf1dad88,bf1dad8a) at syscall+0x300
Xint0x80_syscall() at Xint0x80_syscall+0x1f
--- syscall (98, FreeBSD ELF32, connect), eip = 0x28101d23, esp = 0xbf1dad74, ebp = 0xbf1dae10 ---

src/sys/kern/uipc_syscalls.c,v 1.199
src/sys/kern/uipc_usrreq.c,v 1.135
src/sys/kern/uipc_socket.c,v 1.207

(gdb) l *unp_connect2+0x2a
0x1f93 is in unp_connect2 (/usr/src/sys/kern/uipc_usrreq.c:892).
887             UNP_LOCK_ASSERT();
888
889             if (so2->so_type != so->so_type)
890                     return (EPROTOTYPE);
891             unp2 = sotounpcb(so2);
892             unp->unp_conn = unp2;
893             switch (so->so_type) {
894
895             case SOCK_DGRAM:
896                     LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink);

(gdb) l *unp_connect+0x3d5
0x1e24 is in unp_connect (/usr/src/sys/kern/uipc_usrreq.c:865).
860                     SOCK_UNLOCK(so);
861     #endif
862
863                     so2 = so3;
864             }
865             error = unp_connect2(so, so2);
866     bad2:
867             UNP_UNLOCK();
868             mtx_lock(&Giant);
869     bad:

(gdb) l *uipc_connect+0x76
0x2dd is in uipc_connect (/usr/src/sys/kern/uipc_usrreq.c:179).
174             KASSERT(td == curthread, ("uipc_connect: td != curthread"));
175
176             if (unp == NULL)
177                     return (EINVAL);
178             UNP_LOCK();
179             error = unp_connect(so, nam, td);
180             UNP_UNLOCK();
181             return (error);
182     }
183

(gdb) l *soconnect+0x54
0x100f is in soconnect (/usr/src/sys/kern/uipc_socket.c:518).
513                 (error = sodisconnect(so))))
514                     error = EISCONN;
515             else
516                     error = (*so->so_proto->pr_usrreqs->pru_connect)(so, nam, td);
517             return (error);
518     }
519
520     int
521     soconnect2(so1, so2)
522             struct socket *so1;

(gdb) l *kern_connect+0xb
0xd5e is in kern_connect (/usr/src/sys/kern/uipc_syscalls.c:477).
472     int
473     kern_connect(td, fd, sa)
474             struct thread *td;
475             int fd;
476             struct sockaddr *sa;
477     {
478             struct socket *so;
479             int error, s;
480             int interrupted = 0;
481