linux-toradex.git/lib/locking-selftest.c, branch v4.14-rc5

locking/selftest: Avoid false BUG report

2017-10-10T08:04:29+00:00

The work-around for the expected failure is providing another failure :/

Only when CONFIG_PROVE_LOCKING=y do we increment unexpected_testcase_failures,
so only then do we need to decrement, otherwise we'll end up with a negative
number and that will again trigger a BUG (printout, not crash).

Reported-by: Fengguang Wu 
Tested-by: Fengguang Wu 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Fixes: d82fed752942 ("locking/lockdep/selftests: Fix mixed read-write ABBA tests")
Signed-off-by: Ingo Molnar

locking/lockdep/selftests: Fix mixed read-write ABBA tests

2017-08-29T13:15:17+00:00

Commit:

  e91498589746 ("locking/lockdep/selftests: Add mixed read-write ABBA tests")

adds an explicit FAILURE to the locking selftest but overlooked the
fact that this kills lockdep. Fudge the test to avoid this.

Signed-off-by: Peter Zijlstra (Intel) 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: hpa@zytor.com
Link: http://lkml.kernel.org/r/20170828124245.xlo2yshxq2btgmuf@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar

locking/lockdep/selftests: Add mixed read-write ABBA tests

2017-08-25T09:06:31+00:00

Currently lockdep has limited support for recursive readers, add a few
mixed read-write ABBA selftests to show the extend of these
limitations.

  [    0.000000] ----------------------------------------------------------------------------
  [    0.000000]                                  | spin |wlock |rlock |mutex | wsem | rsem |
  [    0.000000]   --------------------------------------------------------------------------

  [    0.000000]   mixed read-lock/lock-write ABBA:             |FAILED|             |  ok  |
  [    0.000000]    mixed read-lock/lock-read ABBA:             |  ok  |             |  ok  |
  [    0.000000]  mixed write-lock/lock-write ABBA:             |  ok  |             |  ok  |

This clearly illustrates the case where lockdep fails to find a
deadlock.

Signed-off-by: Peter Zijlstra (Intel) 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: boqun.feng@gmail.com
Cc: byungchul.park@lge.com
Cc: david@fromorbit.com
Cc: johannes@sipsolutions.net
Cc: oleg@redhat.com
Cc: tj@kernel.org
Signed-off-by: Ingo Molnar

locking/selftest: Add RT-mutex support

2017-06-08T08:35:50+00:00

Now that RT-mutex has lockdep annotations, add them to the selftest.

Signed-off-by: Peter Zijlstra (Intel) 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

locking/selftest: Remove the bad unlock ordering test

2017-06-08T08:35:49+00:00

There is no such thing as a bad unlock order.

Signed-off-by: Peter Zijlstra (Intel) 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

locking/selftest: Fix output since KERN_CONT changes

2016-11-25T06:12:19+00:00

Since the KERN_CONT changes the locking-selftest output is messed up, eg:

  ----------------------------------------------------------------------------
                                   | spin |wlock |rlock |mutex | wsem | rsem |
    --------------------------------------------------------------------------
                       A-A deadlock:
    ok  |
    ok  |
    ok  |
    ok  |
    ok  |
    ok  |

Use pr_cont() to get it looking normal again:

  ----------------------------------------------------------------------------
                                   | spin |wlock |rlock |mutex | wsem | rsem |
    --------------------------------------------------------------------------
                       A-A deadlock:  ok  |  ok  |  ok  |  ok  |  ok  |  ok  |

Reported-by: Christian Kujau 
Signed-off-by: Michael Ellerman 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linuxppc-dev@ozlabs.org
Link: http://lkml.kernel.org/r/1480027528-934-1-git-send-email-mpe@ellerman.id.au
Signed-off-by: Ingo Molnar

sched: Introduce preempt_count accessor functions

2013-09-25T12:07:32+00:00

Replace the single preempt_count() 'function' that's an lvalue with
two proper functions:

 preempt_count() - returns the preempt_count value as rvalue
 preempt_count_set() - Allows setting the preempt-count value

Also provide preempt_count_ptr() as a convenience wrapper to implement
all modifying operations.

Signed-off-by: Peter Zijlstra 
Link: http://lkml.kernel.org/n/tip-orxrbycjozopqfhb4dxdkdvb@git.kernel.org
[ Fixed build failure. ]
Signed-off-by: Ingo Molnar

mutex: Move ww_mutex definitions to ww_mutex.h

2013-07-12T10:07:46+00:00

Move the definitions for wound/wait mutexes out to a separate
header, ww_mutex.h. This reduces clutter in mutex.h, and
increases readability.

Suggested-by: Linus Torvalds 
Signed-off-by: Maarten Lankhorst 
Acked-by: Peter Zijlstra 
Acked-by: Rik van Riel 
Acked-by: Maarten Lankhorst 
Cc: Dave Airlie 
Link: http://lkml.kernel.org/r/51D675DC.3000907@canonical.com
[ Tidied up the code a bit. ]
Signed-off-by: Ingo Molnar

locking-selftests: Handle unexpected failures more strictly

2013-06-26T10:10:59+00:00

When CONFIG_PROVE_LOCKING is not enabled, more tests are
expected to pass unexpectedly, but there no tests that should
start to fail that pass with CONFIG_PROVE_LOCKING enabled.

Signed-off-by: Maarten Lankhorst 
Acked-by: Peter Zijlstra 
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Cc: rostedt@goodmis.org
Cc: daniel@ffwll.ch
Cc: Linus Torvalds 
Cc: Andrew Morton 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/20130620113151.4001.77963.stgit@patser
Signed-off-by: Ingo Molnar

mutex: Add more w/w tests to test EDEADLK path handling

2013-06-26T10:10:58+00:00

Signed-off-by: Maarten Lankhorst 
Acked-by: Peter Zijlstra 
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Cc: rostedt@goodmis.org
Cc: daniel@ffwll.ch
Cc: Linus Torvalds 
Cc: Andrew Morton 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/20130620113141.4001.54331.stgit@patser
Signed-off-by: Ingo Molnar