Re: occasional system lock up in 6.0_BETA and 6.99.5

Hi,

With DDB backtrace we can see the followings;

db> bt
0x0060bd90: at comintr+0x590
0x0060bde0: at pic_handle_intr+0x198
0x0060be20: at trapstart+0x684
0x0060bef0: at sched_curcpu_runnable_p+0x2c <<< HERE <<<
0x0060bf00: at idle_loop+0xe8
0x0060bf20: at cpu_lwp_bootstrap+0xc
saved LR(0x7ffffd) is invalid.

Here is the objdump list of the offending code;

00181800 <sched_curcpu_runnable_p>:
  181800:       7c 08 02 a6     mflr    r0
  181804:       94 21 ff f0     stwu    r1,-16(r1)
  181808:       93 e1 00 0c     stw     r31,12(r1)
  18180c:       90 01 00 14     stw     r0,20(r1)
  181810:       48 00 6a 95     bl      1882a4 <kpreempt_disable>
  181814:       7d 30 42 a6     mfsprg  r9,0
  181818:       81 29 00 30     lwz     r9,48(r9)
  18181c:       80 69 00 1c     lwz     r3,28(r9)
  181820:       7c 63 00 34     cntlzw  r3,r3
  181824:       54 63 d9 7e     rlwinm  r3,r3,27,5,31
  181828:       68 7f 00 01     xori    r31,r3,1
  18182c:       48 00 71 c5     bl      1889f0 <kpreempt_enable> <<< L@@K <<<
  181830:       80 01 00 14     lwz     r0,20(r1)
  181834:       7f e3 fb 78     mr      r3,r31
  181838:       83 e1 00 0c     lwz     r31,12(r1)
  18183c:       38 21 00 10     addi    r1,r1,16
  181840:       7c 08 03 a6     mtlr    r0
  181844:       4e 80 00 20     blr

00181848 <sched_print_runqueue>:
  181848:       7c 08 02 a6     mflr    r0
   ...

Toru Nishimura / ALKYL Technology