linux-toradex.git/kernel/torture.c, branch v3.15

rcutorture: Gracefully handle NULL cleanup hooks

2014-02-23T17:04:39+00:00

Although most torture tests will have some cleanup hook, it is possible
that one might not.  This commit therefore enables graceful handling of
a NULL cleanup hook during torture-test shutdown.

Signed-off-by: Paul E. McKenney 
Reviewed-by: Josh Triplett

rcutorture: Stop generic kthreads in torture_cleanup()

2014-02-23T17:04:27+00:00

The specific torture modules (like rcutorture) need to call
torture_cleanup() in any case, so this commit makes torture_cleanup()
deal with torture_shutdown_cleanup() and torture_stutter_cleanup() so
that the specific modules don't have to deal with these details.

Signed-off-by: Paul E. McKenney 
Reviewed-by: Josh Triplett

rcutorture: Abstract torture_stop_kthread()

2014-02-23T17:04:25+00:00

Stopping of kthreads is not RCU-specific, so this commit abstracts
out torture_stop_kthread(), saving a few lines of code in the process.

Signed-off-by: Paul E. McKenney 
Reviewed-by: Josh Triplett

rcutorture: Abstract torture_create_kthread()

2014-02-23T17:03:24+00:00

Creation of kthreads is not RCU-specific, so this commit abstracts
out torture_create_kthread(), saving a few tens of lines of code in
the process.

This change requires modifying VERBOSE_TOROUT_ERRSTRING() to take a
non-const string, so that _torture_create_kthread() can avoid an
open-coded substitute.

Signed-off-by: Paul E. McKenney 
Reviewed-by: Josh Triplett

rcutorture: Fix rcutorture shutdown races

2014-02-23T17:03:21+00:00

Not all of the rcutorture kthreads waited for kthread_should_stop()
before returning from their top-level functions, and none of them
used torture_shutdown_absorb() properly.  These problems can result in
segfaults and hangs at shutdown time, and some recent changes perturbed
timing sufficiently to make them much more probable.  This commit
therefore creates a torture_kthread_stopping() function that does the
proper kthread shutdown dance in one centralized location.

Accommodate this grouping by making VERBOSE_TOROUT_STRING() capable of
taking a non-const string as its argument, which allows the new
torture_kthread_stopping() to pass its "title" argument directly to
the updated version of VERBOSE_TOROUT_STRING().

Signed-off-by: Paul E. McKenney

rcutorture: Announce task creation

2014-02-23T17:03:20+00:00

A few "stealth-start rcutorture kthreads" have accumulated over the years,
so this commit adds console-log announcements (but only if the torture
tests are running verbose).

Signed-off-by: Paul E. McKenney 
Reviewed-by: Josh Triplett

rcutorture: Abstract torture_shutdown()

2014-02-23T17:03:18+00:00

Because auto-shutdown of torture testing is not specific to RCU,
this commit moves the auto-shutdown function to kernel/torture.c.

Signed-off-by: Paul E. McKenney 
Reviewed-by: Josh Triplett

rcutorture: Apply ACCESS_ONCE() to racy fullstop accesses

2014-02-23T17:03:16+00:00

Because the fullstop variable can be accessed while it is being updated,
this commit avoids any resulting compiler mischief through use of
ACCESS_ONCE() for non-initialization accesses to this shared variable.

Signed-off-by: Paul E. McKenney 
Reviewed-by: Josh Triplett

rcutorture: Abstract stutter_wait()

2014-02-23T17:02:54+00:00

Because stuttering the test load (stopping and restarting it) is useful
for non-RCU testing, this commit moves the load-stuttering functionality
to kernel/torture.c.

Signed-off-by: Paul E. McKenney 
Reviewed-by: Josh Triplett

rcutorture: Add diagnostic for unscheduled system shutdown

2014-02-23T17:01:13+00:00

Currently, rcutorture can terminate via rmmod, via self-shutdown,
via something else shutting the system down, or of course the usual
catastrophic termination.  The first two get flagged, so this commit adds
a message for the third.  For the fourth, your warranty is void as always.

Signed-off-by: Paul E. McKenney 
Reviewed-by: Josh Triplett