panic with ULE+PREEMPTION

[Jon Noack]

On 02/11/05 22:08, Jon Noack wrote:
> After the recent discussion on stable@, I decided to try ULE again. When 
> attempting to log into Squirrelmail on my RELENG_5 server (sources from 
> late Wednesday night), I got the following panic:
> 
> Fatal trap 12: page fault while in kernel mode
> cpuid = 1; apic id = 01
> fault virtual address   = 0x150
> fault code              = supervisor read, page not present
> instruction pointer     = 0x8:0xc04e1152
> stack pointer           = 0x10:0xe4de1a4c
> frame pointer           = 0x10:0xe4de1a70
> code segment            = base 0x0, limit 0xfffff, type 0x1b
>                         = DPL 0, pres 1, def32 1, gran 1
> processor eflags        = resume, IOPL = 0
> current process         = 36 (swi1: net)

Got another one:
Fatal trap 12: page fault while in kernel mode
cpuid = 1; apic id = 01
fault virtual address   = 0x4c
fault code              = supervisor read, page not present
instruction pointer     = 0x8:0xc04e1094
stack pointer           = 0x10:0xeb2bfa3c
frame pointer           = 0x10:0xeb2bfa50
code segment            = base 0x0, limit 0xfffff, type 0x1b
                         = DPL 0, pres 1, def32 1, gran 1
processor eflags        = resume, IOPL = 0
current process         = 302 (named)

(gdb) l *0xc04e1094
0xc04e1094 is in sched_choose (/usr/src/sys/kern/sched_ule.c:1650).
1645                    kseq_assign(kseq);
1646    #endif
1647            ke = kseq_choose(kseq);
1648            if (ke) {
1649    #ifdef SMP
1650                    if (ke->ke_ksegrp->kg_pri_class == PRI_IDLE)
1651                            if (kseq_idled(kseq) == 0)
1652                                    goto restart;
1653    #endif
1654                    kseq_runq_rem(kseq, ke);

Jon