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mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-23 20:53:53 +08:00
linux-next/Documentation/locking
Ingo Molnar e966eaeeb6 locking/lockdep: Remove the cross-release locking checks
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 <byungchul.park@lge.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-12 12:38:51 +01:00
..
00-INDEX Update of Documentation/00-INDEX 2014-12-29 15:27:54 -07:00
lockdep-design.txt locking/Documentation/lockdep: Fix spelling mistakes 2016-04-28 10:40:57 +02:00
lockstat.txt locking/Documentation/lockstat: Fix typo - lokcing -> locking 2015-09-18 09:27:28 +02:00
locktorture.txt locktorture: Support rtmutex torturing 2015-10-06 11:24:40 -07:00
mutex-design.txt locking/Documentation: Update locking/mutex-design.txt disadvantages 2014-08-13 10:32:04 +02:00
rt-mutex-design.txt Documentation: fix locking rt-mutex doc refs 2017-10-19 12:56:44 -06:00
rt-mutex.txt rtmutex: update rt-mutex 2017-08-24 13:38:14 -06:00
spinlocks.txt
ww-mutex-design.txt locking/ww_mutex/Documentation: Update the design document 2017-01-14 11:14:55 +01:00