Backtrace of every the threads

Ricardo Ribalda Delgado ricardo.ribalda at
Thu Feb 11 08:56:32 EST 2016

Hi Valdis

On Wed, Feb 10, 2016 at 2:37 PM,  <Valdis.Kletnieks at> wrote:
> See what happens when you do 'echo t > /proc/sysrq-trigger'.

This is exactly what I was needing :) I owe you a beer.

> Note that you probably *don't* actually want a trace of *all* tasks (hint -
> what happens on a large system that has 2,000 cores on it)?

This is a embedded system with "only" 70 process.

I agree that on another system this is not the way to debug it.

> What problem are you trying to solve by getting a trace of everything? (Hint -
> what meaning does a userspace stack traceback have if you're looking at
> the corresponding kernel stack trace?)

I was doing:

cat /dev/video0

And the open()  syscall sometimes was stalling.

I wanted to know at what place open() syscall was waiting...

The error was due to a wrong locking methodology (in my code)

Thanks again!

Ricardo Ribalda

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