interruptible sleep tasks

interruptible sleep tasks

[Muni Sekhar]

Hi All,

During kernel drivers testing I see lot of user mode applications
blocks forever in interruptible sleep mode.  Is there any way to get
the corresponding kernel functions stack trace ?

I see kernel has ?hung_task_timeout_secs? parameter and when a task in
D state did not get scheduled for more than this value report a
warning.

Similarly is it possible to get a warning or kernel functions stack
trace when a task in ?S - interruptible sleep mode? and did not get
scheduled for certain duration?



-- 
Thanks,
Sekhar

interruptible sleep tasks

[valdis.kletnieks at vt.edu]

On Tue, 11 Sep 2018 16:26:40 +0530, Muni Sekhar said:
> During kernel drivers testing I see lot of user mode applications
> blocks forever in interruptible sleep mode.  Is there any way to get
> the corresponding kernel functions stack trace ?

cat /proc/NNN/stack   should do the trick.

> Similarly is it possible to get a warning or kernel functions stack
> trace when a task in ???S - interruptible sleep mode??? and did not get
> scheduled for certain duration?

Take a look at the number of processes in that state *normally* on a desktop
system:

[~] ps ax | grep S | wc -l
218

And that's running e16 as a window manager, not a full Gnome environment.

That's the *normal* state for a process or kernel thread waiting for work.