coretemp(4) lockups on 6-stable

[pluknet]

2009/6/15 pluknet <pluknet at gmail.com>:
> This is 6.4-stable from April.
>
> System locks up while in `sysctl dev.cpu` (with coretemp kldloaded).

Small follow-up:

Just one of my wild guesses is that coretemp doesn't play nice with ncpu > 4.
A problem box is 8-way cpu. I always observe this lockup when
sched_bind(curthread, cpu) called with cpu==4. While on another box
`sysctl dev.cpu` works good and that box have only 4 cpu cores.

>
> So as far as I understand sched_bind() binds an executing thread to
> nonexistent CPU 255.
> Same behavior on coretemp built on 6.2.
>
> db> ps
>  pid  ppid  pgrp   uid   state   wmesg     wchan    cmd
> 34381 34380 34381     0  R+      CPU 255             sysctl
> [...]
> db> bt 34381
> Tracing pid 34381 tid 100166 td 0xc8634680
> sched_switch(c8634680,0,1) at sched_switch+0x143
> mi_switch(1,0,c86347e0,4,c0a4e510,...) at mi_switch+0x1ba
> sched_bind(c8634680,4,c856f3b0,0,c0836b3b,...) at sched_bind+0x52
> coretemp_get_temp_sysctl(c8ef56c0,c908c200,0,eebebc04,c8ef56c0,...) at
> coretemp_get_temp_sysctl+0x47
> sysctl_root(0,eebebc74,4,eebebc04) at sysctl_root+0x107
> userland_sysctl(c8634680,eebebc74,4,0,bfbfda8c,0,0,0,eebebc70,0) at
> userland_sysctl+0x112
> __sysctl(c8634680,eebebd04) at __sysctl+0x93
> syscall(3b,3b,3b,4,bfbfda8c,...) at syscall+0x2bf
> Xint0x80_syscall() at Xint0x80_syscall+0x1f
> --- syscall (202, FreeBSD ELF32, __sysctl), eip = 0x2812407b, esp =
> 0xbfbfd9fc, ebp = 0xbfbfda38 ---
>
> static int
> coretemp_get_temp(device_t dev)
> {
>        uint64_t msr;
>        int temp;
>        int cpu = device_get_unit(dev);
>        struct coretemp_softc *sc = device_get_softc(dev);
>        char stemp[16];
>
>        mtx_lock_spin(&sched_lock);
>        sched_bind(curthread, cpu);
>         ^^^
>        mtx_unlock_spin(&sched_lock);
>
>
> --
> wbr,
> pluknet
>



-- 
wbr,
pluknet