[patch] make pipes use event aware wakeups

From: Davide Libenzi
Date: Thu Dec 16 2010 - 15:32:25 EST


I thought this was alreay merged, but this thread brought to my attention
it wasn't:

https://lkml.org/lkml/2010/12/15/234

This patch sends the events the wakeup refers to, so that epoll, and even
the new poll code in fs/select.c can avoid wakeups in events are not
matching the requested set.


Signed-off-by: Davide Libenzi <davidel@xxxxxxxxxxxxxxx>


- Davide


---
fs/pipe.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

Index: linux-2.6.mod/fs/pipe.c
===================================================================
--- linux-2.6.mod.orig/fs/pipe.c 2010-12-15 20:49:48.000000000 -0800
+++ linux-2.6.mod/fs/pipe.c 2010-12-15 20:51:42.000000000 -0800
@@ -441,7 +441,7 @@
break;
}
if (do_wakeup) {
- wake_up_interruptible_sync(&pipe->wait);
+ wake_up_interruptible_sync_poll(&pipe->wait, POLLOUT);
kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT);
}
pipe_wait(pipe);
@@ -450,7 +450,7 @@

/* Signal writers asynchronously that there is more room. */
if (do_wakeup) {
- wake_up_interruptible_sync(&pipe->wait);
+ wake_up_interruptible_sync_poll(&pipe->wait, POLLOUT);
kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT);
}
if (ret > 0)
@@ -612,7 +612,7 @@
break;
}
if (do_wakeup) {
- wake_up_interruptible_sync(&pipe->wait);
+ wake_up_interruptible_sync_poll(&pipe->wait, POLLIN);
kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
do_wakeup = 0;
}
@@ -623,7 +623,7 @@
out:
mutex_unlock(&inode->i_mutex);
if (do_wakeup) {
- wake_up_interruptible_sync(&pipe->wait);
+ wake_up_interruptible_sync_poll(&pipe->wait, POLLIN);
kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
}
if (ret > 0)
@@ -715,7 +715,7 @@
if (!pipe->readers && !pipe->writers) {
free_pipe_info(inode);
} else {
- wake_up_interruptible_sync(&pipe->wait);
+ wake_up_interruptible_sync_poll(&pipe->wait, POLLIN | POLLOUT);
kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT);
}
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