Re: [stable 4.19] [PANIC]: tracing: Centralize preemptirq tracepoints and unify their usage

[Naresh Kamboju]

On Fri, 25 Sep 2020 at 10:45, Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Fri, Sep 25, 2020 at 10:13:05AM +0530, Naresh Kamboju wrote:
> > >From stable rc 4.18.1 onwards to today's stable rc 4.19.147
> >
> > There are two problems  while running LTP tracing tests
> > 1) kernel panic  on i386, qemu_i386, x86_64 and qemu_x86_64 [1]
> > 2) " segfault at 0 ip " and "Code: Bad RIP value" on x86_64 and qemu_x86_64 [2]
> > Please refer to the full test logs from below links.
> >
> > The first bad commit found by git bisect.
> >    commit: c3bc8fd637a9623f5c507bd18f9677effbddf584
> >    tracing: Centralize preemptirq tracepoints and unify their usage
> >
> > Reported-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx>
>
> So this also is reproducable in 5.4 and Linus's tree right now?

No.
The reported issues are not reproducible on 5.4, 5.8 and Linus's tree.

>
> Or are newer kernels working fine?

No.
There are different issues while testing LTP tracing on 5.4, 5.8 and
Linus 's 5.9.

NETDEV WATCHDOG: eth0 (igb): transmit queue 2 timed out
WARNING: CPU: 1 PID: 331 at net/sched/sch_generic.c:442 dev_watchdog+0x4c7/0x4d0
https://lore.kernel.org/stable/CA+G9fYtS_nAX=sPV8zTTs-nOdpJ4uxk9sqeHOZNuS4WLvBcPGg@xxxxxxxxxxxxxx/

I see this on 5.4, 5.8 and Linus 's 5.9.
rcu: INFO: rcu_sched self-detected stall on CPU
? ftrace_graph_caller+0xc0/0xc0
https://lore.kernel.org/stable/CA+G9fYsdTLRj55_bvod8Sf+0zvK0RRMp5+FeJcOx5oAcAKOGXA@xxxxxxxxxxxxxx/T/#u

>
> thanks,
>
> greg k-h

- Naresh