SCHED: add some "wait..on_bit...timeout()" interfaces.
In commit c1221321b7c25b53204447cff9949a6d5a7ddddc
sched: Allow wait_on_bit_action() functions to support a timeout
I suggested that a "wait_on_bit_timeout()" interface would not meet my
need. This isn't true - I was just over-engineering.
Including a 'private' field in wait_bit_key instead of a focused
"timeout" field was just premature generalization. If some other
use is ever found, it can be generalized or added later.
So this patch renames "private" to "timeout" with a meaning "stop
waiting when "jiffies" reaches or passes "timeout",
and adds two of the many possible wait..bit..timeout() interfaces:
wait_on_page_bit_killable_timeout(), which is the one I want to use,
and out_of_line_wait_on_bit_timeout() which is a reasonably general
example. Others can be added as needed.
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/mm/filemap.c b/mm/filemap.c
index 90effcd..cbe5a90 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -703,6 +703,19 @@
bit_wait_io, TASK_KILLABLE);
}
+int wait_on_page_bit_killable_timeout(struct page *page,
+ int bit_nr, unsigned long timeout)
+{
+ DEFINE_WAIT_BIT(wait, &page->flags, bit_nr);
+
+ wait.key.timeout = jiffies + timeout;
+ if (!test_bit(bit_nr, &page->flags))
+ return 0;
+ return __wait_on_bit(page_waitqueue(page), &wait,
+ bit_wait_io_timeout, TASK_KILLABLE);
+}
+EXPORT_SYMBOL_GPL(wait_on_page_bit_killable_timeout);
+
/**
* add_page_wait_queue - Add an arbitrary waiter to a page's wait queue
* @page: Page defining the wait queue of interest