Re: [PATCH RT 07/12] dump stack: dont disable preemption during trace

[Steven Rostedt]

On Tue, 1 Mar 2016 09:45:05 -0500
Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:

> On Sat, 27 Feb 2016 11:32:06 +0100
> Sebastian Andrzej Siewior <sebastian@xxxxxxxxxxxxx> wrote:
> 
> > On 2016-02-26 16:32:42 [-0500], Steven Rostedt wrote:  
> > > 3.18.27-rt26-rc1 stable review patch.
> > > If anyone has any objections, please let me know.    
> > 
> > Please merge this one along with "kernel: migrate_disable() do fastpath
> > in atomic & irqs-off". Otherwise we might get recursive with lockdep and
> > CPU-hotplug (if we go after hp->lock in pin_current_cpu()).  
> 
> Interesting. When I pulled this patch into 4.1-rt, it caused the system
> to lock up. I'm looking into it now.

And that's because this commit also needs:

"kernel: softirq: unlock with irqs on"

And due to the WARN_ON_ONCE() issue (that I just posted a patch to fix
mainline), it caused my system to reboot.

http://lkml.kernel.org/r/20160301110939.1b786f49@xxxxxxxxxxxxxxxxxx

-- Steve