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authorLinus Torvalds <torvalds@linux-foundation.org>2017-11-13 21:38:26 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2017-11-13 21:38:26 +0100
commit8e9a2dba8686187d8c8179e5b86640e653963889 (patch)
treea4ba543649219cbb28d91aab65b785d763f5d069 /Documentation/memory-barriers.txt
parentMerge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kerne... (diff)
parentlocking/x86: Use LOCK ADD for smp_mb() instead of MFENCE (diff)
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Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core locking updates from Ingo Molnar: "The main changes in this cycle are: - Another attempt at enabling cross-release lockdep dependency tracking (automatically part of CONFIG_PROVE_LOCKING=y), this time with better performance and fewer false positives. (Byungchul Park) - Introduce lockdep_assert_irqs_enabled()/disabled() and convert open-coded equivalents to lockdep variants. (Frederic Weisbecker) - Add down_read_killable() and use it in the VFS's iterate_dir() method. (Kirill Tkhai) - Convert remaining uses of ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE(). Most of the conversion was Coccinelle driven. (Mark Rutland, Paul E. McKenney) - Get rid of lockless_dereference(), by strengthening Alpha atomics, strengthening READ_ONCE() with smp_read_barrier_depends() and thus being able to convert users of lockless_dereference() to READ_ONCE(). (Will Deacon) - Various micro-optimizations: - better PV qspinlocks (Waiman Long), - better x86 barriers (Michael S. Tsirkin) - better x86 refcounts (Kees Cook) - ... plus other fixes and enhancements. (Borislav Petkov, Juergen Gross, Miguel Bernal Marin)" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits) locking/x86: Use LOCK ADD for smp_mb() instead of MFENCE rcu: Use lockdep to assert IRQs are disabled/enabled netpoll: Use lockdep to assert IRQs are disabled/enabled timers/posix-cpu-timers: Use lockdep to assert IRQs are disabled/enabled sched/clock, sched/cputime: Use lockdep to assert IRQs are disabled/enabled irq_work: Use lockdep to assert IRQs are disabled/enabled irq/timings: Use lockdep to assert IRQs are disabled/enabled perf/core: Use lockdep to assert IRQs are disabled/enabled x86: Use lockdep to assert IRQs are disabled/enabled smp/core: Use lockdep to assert IRQs are disabled/enabled timers/hrtimer: Use lockdep to assert IRQs are disabled/enabled timers/nohz: Use lockdep to assert IRQs are disabled/enabled workqueue: Use lockdep to assert IRQs are disabled/enabled irq/softirqs: Use lockdep to assert IRQs are disabled/enabled locking/lockdep: Add IRQs disabled/enabled assertion APIs: lockdep_assert_irqs_enabled()/disabled() locking/pvqspinlock: Implement hybrid PV queued/unfair locks locking/rwlocks: Fix comments x86/paravirt: Set up the virt_spin_lock_key after static keys get initialized block, locking/lockdep: Assign a lock_class per gendisk used for wait_for_completion() workqueue: Remove now redundant lock acquisitions wrt. workqueue flushes ...
Diffstat (limited to 'Documentation/memory-barriers.txt')
-rw-r--r--Documentation/memory-barriers.txt12
1 files changed, 0 insertions, 12 deletions
diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt
index 519940ec767f..479ecec80593 100644
--- a/Documentation/memory-barriers.txt
+++ b/Documentation/memory-barriers.txt
@@ -1880,18 +1880,6 @@ There are some more advanced barrier functions:
See Documentation/atomic_{t,bitops}.txt for more information.
- (*) lockless_dereference();
-
- This can be thought of as a pointer-fetch wrapper around the
- smp_read_barrier_depends() data-dependency barrier.
-
- This is also similar to rcu_dereference(), but in cases where
- object lifetime is handled by some mechanism other than RCU, for
- example, when the objects removed only when the system goes down.
- In addition, lockless_dereference() is used in some data structures
- that can be used both with and without RCU.
-
-
(*) dma_wmb();
(*) dma_rmb();