Re: [PATCH v2 1/7] sched/fair: Fix zero_vruntime tracking

[Steven Rostedt]

On Fri, 27 Mar 2026 22:44:28 -0700
John Stultz <jstultz@xxxxxxxxxx> wrote:

> I'll continue digging next week on this, but wanted to share in case
> anyone else sees something obvious first.

FYI, you can add a trace_printk() around all the areas that assign
cfs_rq->curr, and if you use the persistent ring buffer you can retrieve
the output of all the events that lead up to the crash.

Add to the kernel command line:

   reserve_mem=100M:12M:trace trace_instance=boot_mapped^traceprintk^traceoff@trace

And before starting your testing:

  echo 1 > /sys/kernel/tracing/instances/boot_mapped/tracing_on

If all goes well, after the crash you should see the output in:

  cat /sys/kernel/tracing/instances/boot_mapped/trace

-- Steve