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| author | Ingo Molnar <mingo@kernel.org> | 2017-03-05 13:35:27 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-06-20 13:18:29 +0300 |
| commit | 76c85ddc4695bb7b8209bfeff11f5156088f9197 (patch) | |
| tree | bd6772616e1c304097cd6d11f3654bc01c4a9127 /include/linux/wait.h | |
| parent | 2141713616c652aeabf2dd5c1e89bc601c4fed6a (diff) | |
| download | linux-76c85ddc4695bb7b8209bfeff11f5156088f9197.tar.xz | |
sched/wait: Standardize wait_bit_queue naming
So wait-bit-queue head variables are often named:
struct wait_bit_queue *q
... which is a bit ambiguous and super confusing, because
they clearly suggest wait-queue head semantics and behavior
(they rhyme with the old wait_queue_t *q naming), while they
are extended wait-queue _entries_, not heads!
They are misnomers in two ways:
- the 'wait_bit_queue' leaves open the question of whether
it's an entry or a head
- the 'q' parameter and local variable naming falsely implies
that it's a 'queue' - while it's an entry.
This resulted in sometimes confusing cases such as:
finish_wait(wq, &q->wait);
where the 'q' is not a wait-queue head, but a wait-bit-queue entry.
So improve this all by standardizing wait-bit-queue nomenclature
similar to wait-queue head naming:
struct wait_bit_queue => struct wait_bit_queue_entry
q => wbq_entry
Which makes it all a much clearer:
struct wait_bit_queue_entry *wbq_entry
... and turns the former confusing piece of code into:
finish_wait(wq_head, &wbq_entry->wq_entry;
which IMHO makes it apparently clear what we are doing,
without having to analyze the context of the code: we are
adding a wait-queue entry to a regular wait-queue head,
which entry is embedded in a wait-bit-queue entry.
I'm not a big fan of acronyms, but repeating wait_bit_queue_entry
in field and local variable names is too long, so Hopefully it's
clear enough that 'wq_' prefixes stand for wait-queues, while
'wbq_' prefixes stand for wait-bit-queues.
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>
Diffstat (limited to 'include/linux/wait.h')
| -rw-r--r-- | include/linux/wait.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/include/linux/wait.h b/include/linux/wait.h index 1c8add685f22..fc7c32d82120 100644 --- a/include/linux/wait.h +++ b/include/linux/wait.h @@ -36,7 +36,7 @@ struct wait_bit_key { unsigned long timeout; }; -struct wait_bit_queue { +struct wait_bit_queue_entry { struct wait_bit_key key; struct wait_queue_entry wq_entry; }; @@ -207,8 +207,8 @@ void __wake_up_sync_key(struct wait_queue_head *wq_head, unsigned int mode, int void __wake_up_locked(struct wait_queue_head *wq_head, unsigned int mode, int nr); void __wake_up_sync(struct wait_queue_head *wq_head, unsigned int mode, int nr); void __wake_up_bit(struct wait_queue_head *, void *, int); -int __wait_on_bit(struct wait_queue_head *, struct wait_bit_queue *, wait_bit_action_f *, unsigned); -int __wait_on_bit_lock(struct wait_queue_head *, struct wait_bit_queue *, wait_bit_action_f *, unsigned); +int __wait_on_bit(struct wait_queue_head *, struct wait_bit_queue_entry *, wait_bit_action_f *, unsigned); +int __wait_on_bit_lock(struct wait_queue_head *, struct wait_bit_queue_entry *, wait_bit_action_f *, unsigned); void wake_up_bit(void *, int); void wake_up_atomic_t(atomic_t *); int out_of_line_wait_on_bit(void *, int, wait_bit_action_f *, unsigned); @@ -989,7 +989,7 @@ int wake_bit_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync #define DEFINE_WAIT(name) DEFINE_WAIT_FUNC(name, autoremove_wake_function) #define DEFINE_WAIT_BIT(name, word, bit) \ - struct wait_bit_queue name = { \ + struct wait_bit_queue_entry name = { \ .key = __WAIT_BIT_KEY_INITIALIZER(word, bit), \ .wq_entry = { \ .private = current, \ |