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| author | Wolfram Sang <wsa@the-dreams.de> | 2014-11-04 12:01:41 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2014-11-16 10:58:54 +0100 |
| commit | a1bd5373357d3edc4b97548747d583c3efa484b3 (patch) | |
| tree | 9772a0ec18b3d64d20a043597cfe96f427146778 /kernel/sched/completion.c | |
| parent | f622b429dadf83c3cc2d70f57f407ad85684eb36 (diff) | |
| download | linux-a1bd5373357d3edc4b97548747d583c3efa484b3.tar.gz linux-a1bd5373357d3edc4b97548747d583c3efa484b3.tar.bz2 linux-a1bd5373357d3edc4b97548747d583c3efa484b3.zip | |
sched/completion: Document when to use wait_for_completion_io_*()
As discussed in [1], accounting IO is meant for blkio only. Document that
so driver authors won't use them for device io.
[1] http://thread.gmane.org/gmane.linux.drivers.i2c/20470
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1415098901-2768-1-git-send-email-wsa@the-dreams.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched/completion.c')
| -rw-r--r-- | kernel/sched/completion.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/kernel/sched/completion.c b/kernel/sched/completion.c index a63f4dc27909..607f852b4d04 100644 --- a/kernel/sched/completion.c +++ b/kernel/sched/completion.c @@ -148,7 +148,7 @@ EXPORT_SYMBOL(wait_for_completion_timeout); * * This waits to be signaled for completion of a specific task. It is NOT * interruptible and there is no timeout. The caller is accounted as waiting - * for IO. + * for IO (which traditionally means blkio only). */ void __sched wait_for_completion_io(struct completion *x) { @@ -163,7 +163,8 @@ EXPORT_SYMBOL(wait_for_completion_io); * * This waits for either a completion of a specific task to be signaled or for a * specified timeout to expire. The timeout is in jiffies. It is not - * interruptible. The caller is accounted as waiting for IO. + * interruptible. The caller is accounted as waiting for IO (which traditionally + * means blkio only). * * Return: 0 if timed out, and positive (at least 1, or number of jiffies left * till timeout) if completed. |