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| author | Tejun Heo <tj@kernel.org> | 2008-10-15 22:01:38 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-10-16 11:21:31 -0700 |
| commit | a25d644fc0e232f242d1f3baa63c149c42536ff0 (patch) | |
| tree | c5013caca7978d862f8ea1996c5933495fd7334a /kernel/wait.c | |
| parent | c80cfb0406c01bb5da91bfe30f5cb1fd96831138 (diff) | |
| download | lwn-a25d644fc0e232f242d1f3baa63c149c42536ff0.tar.gz lwn-a25d644fc0e232f242d1f3baa63c149c42536ff0.zip | |
wait: kill is_sync_wait()
is_sync_wait() is used to distinguish between sync and async waits.
Basically sync waits are the ones initialized with init_waitqueue_entry()
and async ones with init_waitqueue_func_entry(). The sync/async
distinction is used only in prepare_to_wait[_exclusive]() and its only
function is to skip setting the current task state if the wait is async.
This has a few problems.
* No one uses it. None of func_entry users use prepare_to_wait()
functions, so the code path never gets executed.
* The distinction is bogus. Maybe back when func_entry is used only
by aio but it's now also used by epoll and in future possibly by 9p
and poll/select.
* Taking @state as argument and ignoring it silenly depending on how
@wait is initialized is just a bad error-prone API.
* It prevents func_entry waits from using wait->private for no good
reason.
This patch kills is_sync_wait() and the associated code paths from
prepare_to_wait[_exclusive](). As there was no user of these code paths,
this patch doesn't cause any behavior difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/wait.c')
| -rw-r--r-- | kernel/wait.c | 14 |
1 files changed, 2 insertions, 12 deletions
diff --git a/kernel/wait.c b/kernel/wait.c index c275c56cf2d3..cd87131f2fc2 100644 --- a/kernel/wait.c +++ b/kernel/wait.c @@ -72,12 +72,7 @@ prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state) spin_lock_irqsave(&q->lock, flags); if (list_empty(&wait->task_list)) __add_wait_queue(q, wait); - /* - * don't alter the task state if this is just going to - * queue an async wait queue callback - */ - if (is_sync_wait(wait)) - set_current_state(state); + set_current_state(state); spin_unlock_irqrestore(&q->lock, flags); } EXPORT_SYMBOL(prepare_to_wait); @@ -91,12 +86,7 @@ prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state) spin_lock_irqsave(&q->lock, flags); if (list_empty(&wait->task_list)) __add_wait_queue_tail(q, wait); - /* - * don't alter the task state if this is just going to - * queue an async wait queue callback - */ - if (is_sync_wait(wait)) - set_current_state(state); + set_current_state(state); spin_unlock_irqrestore(&q->lock, flags); } EXPORT_SYMBOL(prepare_to_wait_exclusive); |