linux-toradex.git/Documentation/locking, branch v4.18-rc7

Merge tag 'v4.16-rc2' into locking/core, to refresh the branch

2018-02-21T08:57:55+00:00

Signed-off-by: Ingo Molnar

Documentation/locking/lockdep: Add section about available annotations

2018-02-14T11:01:22+00:00

Add section about annotations that can be used to perform additional runtime
checking of locking correctness: assert that certain locks are held and
prevent accidental unlocking.

Signed-off-by: Juri Lelli 
Acked-by: Peter Zijlstra (Intel) 
Cc: Jonathan Corbet 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-doc@vger.kernel.org
Link: http://lkml.kernel.org/r/20180213185519.18186-3-juri.lelli@redhat.com
Signed-off-by: Ingo Molnar

Documentation/locking/lockdep: Update info about states

2018-02-14T11:01:22+00:00

Commit:

  d92a8cfcb37e ("locking/lockdep: Rework FS_RECLAIM annotation")

removed the 'reclaim_fs' lockdep STATE.

Reflect the change in the documentation.

While we are at it, also clarify the formula to calculate the number of state bits.

Signed-off-by: Juri Lelli 
Acked-by: Peter Zijlstra (Intel) 
Cc: Jonathan Corbet 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-doc@vger.kernel.org
Link: http://lkml.kernel.org/r/20180213185519.18186-2-juri.lelli@redhat.com
Signed-off-by: Ingo Molnar

Documentation/locking/mutex-design: Update to reflect latest changes

2018-02-11T11:28:58+00:00

Commit 3ca0ff571b09 ("locking/mutex: Rework mutex::owner") reworked the
basic mutex implementation to deal with several problems. Documentation
was however left unchanged and became stale.

Update mutex-design.txt to reflect changes introduced by the above commit.

Signed-off-by: Juri Lelli 
Cc: Andrew Morton 
Cc: Davidlohr Bueso 
Cc: Jonathan Corbet 
Cc: Linus Torvalds 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-doc@vger.kernel.org
Link: http://lkml.kernel.org/r/20180209160114.19980-1-juri.lelli@redhat.com
[ Small readability tweaks to the text. ]
Signed-off-by: Ingo Molnar

Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu

2018-01-03T13:14:18+00:00

Pull RCU updates from Paul E. McKenney:

- Updates to use cond_resched() instead of cond_resched_rcu_qs()
  where feasible (currently everywhere except in kernel/rcu and
  in kernel/torture.c).  Also a couple of fixes to avoid sending
  IPIs to offline CPUs.

- Updates to simplify RCU's dyntick-idle handling.

- Updates to remove almost all uses of smp_read_barrier_depends()
  and read_barrier_depends().

- Miscellaneous fixes.

- Torture-test updates.

Signed-off-by: Ingo Molnar

locking/lockdep: Remove the cross-release locking checks

2017-12-12T11:38:51+00:00

This code (CONFIG_LOCKDEP_CROSSRELEASE=y and CONFIG_LOCKDEP_COMPLETIONS=y),
while it found a number of old bugs initially, was also causing too many
false positives that caused people to disable lockdep - which is arguably
a worse overall outcome.

If we disable cross-release by default but keep the code upstream then
in practice the most likely outcome is that we'll allow the situation
to degrade gradually, by allowing entropy to introduce more and more
false positives, until it overwhelms maintenance capacity.

Another bad side effect was that people were trying to work around
the false positives by uglifying/complicating unrelated code. There's
a marked difference between annotating locking operations and
uglifying good code just due to bad lock debugging code ...

This gradual decrease in quality happened to a number of debugging
facilities in the kernel, and lockdep is pretty complex already,
so we cannot risk this outcome.

Either cross-release checking can be done right with no false positives,
or it should not be included in the upstream kernel.

( Note that it might make sense to maintain it out of tree and go through
  the false positives every now and then and see whether new bugs were
  introduced. )

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

torture: Eliminate torture_runnable and perf_runnable

2017-12-11T17:18:29+00:00

The purpose of torture_runnable is to allow rcutorture and locktorture
to be started and stopped via sysfs when they are built into the kernel
(as in not compiled as loadable modules).  However, the 0444 permissions
for both instances of torture_runnable prevent this use case from ever
being put into practice.  Given that there have been no complaints
about this deficiency, it is reasonable to conclude that no one actually
makes use of this sysfs capability.  The perf_runnable module parameter
for rcuperf is in the same situation.

This commit therefore removes both torture_runnable instances as well
as perf_runnable.

Reported-by: Thomas Gleixner 
Signed-off-by: Paul E. McKenney

Documentation: fix locking rt-mutex doc refs

2017-10-19T18:56:44+00:00

Signed-off-by: Tom Saeger 
Signed-off-by: Jonathan Corbet

Merge branch 'linus' into locking/core, to fix up conflicts

2017-09-04T09:01:18+00:00

 Conflicts:
	mm/page_alloc.c

Signed-off-by: Ingo Molnar

rtmutex: update rt-mutex

2017-08-24T19:38:14+00:00

The rtmutex remove a pending owner bit in in rt_mutex::owner, in
commit 8161239a8bcc ("rtmutex: Simplify PI algorithm and make highest prio task get lock")
But the document was changed accordingly. Updating it to a meaningful
state.

BTW, as 'Steven Rostedt' mentioned:
There is still technically a "Pending Owner", it's just not called
that anymore. The pending owner happens to be the top_waiter of a lock
that has no owner and has been woken up to grab the lock.

Signed-off-by: Alex Shi 
Cc: Steven Rostedt 
Cc: Sebastian Siewior 
Cc: Mathieu Poirier 
Cc: Juri Lelli 
Cc: Thomas Gleixner 
To: linux-doc@vger.kernel.org
To: linux-kernel@vger.kernel.org
To: Jonathan Corbet 
To: Ingo Molnar 
To: Peter Zijlstra 
Signed-off-by: Jonathan Corbet