Re: [PATCH] 2.6.17-rt1 : fix x86_64 oops

[Dipankar Sarma <dipankar@in.ibm.com>]

On Thu, Jun 29, 2006 at 10:11:45PM +0200, Ingo Molnar wrote:
> 
> * Paul E. McKenney <paulmck@us.ibm.com> wrote:
> > OK, I ran this with both torture types (rcu and rcu_bh) on i386 with 
> > CONFIG_PREEMPT=y on 2.6.17-mm4 and didn't see any "scheduling while 
> > atomic" oopses -- or any other oopses, for that matter.
> > 
> > Here is the .config file I used.  What am I missing here?
> 
> hm, i'm seeing some other types of crashes too - so rcutorture could 
> just have been collateral damage. It was on i386, an allyesconfig 
> bzImage kernel.

With 2.6.17-rt5 I see this -

llm17:~/rcutorture # set -o vi^H^H^H^H^H^H^H^H^H./rcutorture.sh ^H^H^H^H^H^H^H^H^H^H^H^H^H^H^H^Hls^H^H./rcutorture.sh ^H^H^H^H^H^H^H^H^H^H^H^H^H^H^H^H
Starting pass 0
Unable to handle kernel paging request at ffffffff88006bd0 RIP:
<ffffffff802597d5>{rcu_process_callbacks+107}
rcutorture: --- End of test: SUCCESS: nreaders=8 stat_interval=1PGD 203027 PUD 205027 PMD 21eb18067 PTE 21829f163
Oops: 0000 [1] PREEMPT SMP
CPU 1
Modules linked in:
Pid: 19, comm: softirq-tasklet Not tainted 2.6.17-rt5 #1
RIP: 0010:[<ffffffff802597d5>] <ffffffff802597d5>{rcu_process_callbacks+107}
RSP: 0000:ffff810220a9deb8  EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffffff80713570 RCX: 0000000000000003
RDX: 0000000000000001 RSI: ffff810220a9c010 RDI: 0000000000000003
RBP: ffffffff88006bd0 R08: ffff810220a9c000 R09: ffff810220a8fed8
R10: ffff810220a8fe08 R11: ffffffff804fdb7e R12: 0000000000000000
R13: ffff8100051a7310 R14: ffffffff80531258 R15: ffffffff807b1310
FS:  0000000000000000(0000) GS:ffff810220b0cd40(0000) knlGS:0000000000000000
CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: ffffffff88006bd0 CR3: 0000000000201000 CR4: 00000000000006e0
Process softirq-tasklet (pid: 19, threadinfo ffff810220a9c000, task ffff810220a9ad30)
Stack: ffff810220a41bc8 ffffffff80713570 00000000000f4240 ffffffff802357ef
       ffff8100051a7310 0000000000000020 ffff810220a41bc8 ffffffff80235f3b
       ffffffff00000001 ffffffff807b1310
Call Trace:
       <ffffffff802357ef>{__tasklet_action+181}
       <ffffffff80235f3b>{ksoftirqd+280}
       <ffffffff80235e23>{ksoftirqd+0}
       <ffffffff80243251>{kthread+212}
       <ffffffff80235e23>{ksoftirqd+0}
       <ffffffff8020a74e>{child_rip+8}
       <ffffffff80235e23>{ksoftirqd+0}
       <ffffffff8024317d>{kthread+0}
       <ffffffff8020a746>{child_rip+0}
---------------------------
| preempt count: 00000001 ]
| 1-level deep critical section nesting:
----------------------------------------

I have been able to reproduce a similar looking oopse with 2.6.16-rt29.
2.6.16-rt20 works fine. I will try to track it down to the exact
release as far as I can.

Thanks
Dipankar