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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-14 17:27:47 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-14 17:27:47 -0800 |
| commit | e857b6fcc5af0fbe042bec7e56a1533fe78ef594 (patch) | |
| tree | 3a54a8f2e83ef5a16c82df1230dd83af70ce63d7 /Documentation/locking/seqlock.rst | |
| parent | 8c1dccc80380fca8db09c2a81f5deb3c49b112b2 (diff) | |
| parent | cb262935a166bdef0ccfe6e2adffa00c0f2d038a (diff) | |
Merge tag 'locking-core-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Thomas Gleixner:
"A moderate set of locking updates:
- A few extensions to the rwsem API and support for opportunistic
spinning and lock stealing
- lockdep selftest improvements
- Documentation updates
- Cleanups and small fixes all over the place"
* tag 'locking-core-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
seqlock: kernel-doc: Specify when preemption is automatically altered
seqlock: Prefix internal seqcount_t-only macros with a "do_"
Documentation: seqlock: s/LOCKTYPE/LOCKNAME/g
locking/rwsem: Remove reader optimistic spinning
locking/rwsem: Enable reader optimistic lock stealing
locking/rwsem: Prevent potential lock starvation
locking/rwsem: Pass the current atomic count to rwsem_down_read_slowpath()
locking/rwsem: Fold __down_{read,write}*()
locking/rwsem: Introduce rwsem_write_trylock()
locking/rwsem: Better collate rwsem_read_trylock()
rwsem: Implement down_read_interruptible
rwsem: Implement down_read_killable_nested
refcount: Fix a kernel-doc markup
completion: Drop init_completion define
atomic: Update MAINTAINERS
atomic: Delete obsolete documentation
seqlock: Rename __seqprop() users
lockdep/selftest: Add spin_nest_lock test
lockdep/selftests: Fix PROVE_RAW_LOCK_NESTING
seqlock: avoid -Wshadow warnings
...
Diffstat (limited to 'Documentation/locking/seqlock.rst')
| -rw-r--r-- | Documentation/locking/seqlock.rst | 21 |
1 files changed, 10 insertions, 11 deletions
diff --git a/Documentation/locking/seqlock.rst b/Documentation/locking/seqlock.rst index a334b584f2b3..64405e5da63e 100644 --- a/Documentation/locking/seqlock.rst +++ b/Documentation/locking/seqlock.rst @@ -89,7 +89,7 @@ Read path:: .. _seqcount_locktype_t: -Sequence counters with associated locks (``seqcount_LOCKTYPE_t``) +Sequence counters with associated locks (``seqcount_LOCKNAME_t``) ----------------------------------------------------------------- As discussed at :ref:`seqcount_t`, sequence count write side critical @@ -115,27 +115,26 @@ The following sequence counters with associated locks are defined: - ``seqcount_mutex_t`` - ``seqcount_ww_mutex_t`` -The plain seqcount read and write APIs branch out to the specific -seqcount_LOCKTYPE_t implementation at compile-time. This avoids kernel -API explosion per each new seqcount LOCKTYPE. +The sequence counter read and write APIs can take either a plain +seqcount_t or any of the seqcount_LOCKNAME_t variants above. -Initialization (replace "LOCKTYPE" with one of the supported locks):: +Initialization (replace "LOCKNAME" with one of the supported locks):: /* dynamic */ - seqcount_LOCKTYPE_t foo_seqcount; - seqcount_LOCKTYPE_init(&foo_seqcount, &lock); + seqcount_LOCKNAME_t foo_seqcount; + seqcount_LOCKNAME_init(&foo_seqcount, &lock); /* static */ - static seqcount_LOCKTYPE_t foo_seqcount = - SEQCNT_LOCKTYPE_ZERO(foo_seqcount, &lock); + static seqcount_LOCKNAME_t foo_seqcount = + SEQCNT_LOCKNAME_ZERO(foo_seqcount, &lock); /* C99 struct init */ struct { - .seq = SEQCNT_LOCKTYPE_ZERO(foo.seq, &lock), + .seq = SEQCNT_LOCKNAME_ZERO(foo.seq, &lock), } foo; Write path: same as in :ref:`seqcount_t`, while running from a context -with the associated LOCKTYPE lock acquired. +with the associated write serialization lock acquired. Read path: same as in :ref:`seqcount_t`. |