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.