--- linux/fs/pipe.c.orig2	Wed Sep 29 11:50:27 1999
+++ linux/fs/pipe.c	Wed Sep 29 12:33:11 1999
@@ -2,6 +2,8 @@
  *  linux/fs/pipe.c
  *
  *  Copyright (C) 1991, 1992, 1999  Linus Torvalds
+ *
+ *  wake-one pipe handling by Ingo Molnar
  */
 
 #include <linux/mm.h>
@@ -32,17 +34,27 @@
  */
 
 /* Drop the inode semaphore and wait for a pipe event, atomically */
-static void pipe_wait(struct inode * inode)
+static inline void __pipe_wait (wait_queue_head_t *wq, struct inode * inode)
 {
 	DECLARE_WAITQUEUE(wait, current);
-	current->state = TASK_INTERRUPTIBLE;
-	add_wait_queue(PIPE_WAIT(*inode), &wait);
+	current->state = TASK_EXCLUSIVE | TASK_INTERRUPTIBLE;
+	add_wait_queue(wq, &wait);
 	up(PIPE_SEM(*inode));
 	schedule();
-	remove_wait_queue(PIPE_WAIT(*inode), &wait);
+	remove_wait_queue(wq, &wait);
 	current->state = TASK_RUNNING;
 }
 
+static void pipe_wait_readqueue (struct inode * inode)
+{
+	__pipe_wait(PIPE_WAIT_READ(*inode), inode);
+}
+
+static void pipe_wait_writequeue (struct inode * inode)
+{
+	__pipe_wait(PIPE_WAIT_WRITE(*inode), inode);
+}
+
 static ssize_t
 pipe_read(struct file *filp, char *buf, size_t count, loff_t *ppos)
 {
@@ -74,7 +86,7 @@
 			goto out;
 
 		for (;;) {
-			pipe_wait(inode);
+			pipe_wait_readqueue(inode);
 			ret = -ERESTARTSYS;
 			if (signal_pending(current))
 				goto out_nolock;
@@ -115,8 +127,8 @@
 	if (!PIPE_LEN(*inode))
 		PIPE_START(*inode) = 0;
 
-	/* Signal writers there is more room.  */
-	wake_up_interruptible(PIPE_WAIT(*inode));
+	/* Signal writers (and pollers) there is more room.  */
+	wake_up_pipe(inode, PIPE_WAIT_WRITE(*inode));
 
 	if (read)
 		UPDATE_ATIME(inode);
@@ -163,7 +175,7 @@
 			goto out;
 	} else {
 		while (PIPE_FREE(*inode) < free) {
-			pipe_wait(inode);
+			pipe_wait_writequeue(inode);
 			ret = -ERESTARTSYS;
 			if (signal_pending(current))
 				goto out_nolock;
@@ -205,8 +217,8 @@
 
 		do {
 			/* This should be a synchronous wake-up: don't do idle reschedules! */
-			wake_up_interruptible(PIPE_WAIT(*inode));
-			pipe_wait(inode);
+			wake_up_pipe(inode, PIPE_WAIT_READ(*inode));
+			pipe_wait_writequeue(inode);
 			if (signal_pending(current))
 				goto out_nolock;
 			if (down_interruptible(PIPE_SEM(*inode)))
@@ -218,7 +230,7 @@
 	}
 
 	/* Signal readers there is more data.  */
-	wake_up_interruptible(PIPE_WAIT(*inode));
+	wake_up_pipe(inode, PIPE_WAIT_READ(*inode));
 
 	ret = (written ? written : -EAGAIN);
 	inode->i_ctime = inode->i_mtime = CURRENT_TIME;
@@ -271,7 +283,7 @@
 	unsigned int mask;
 	struct inode *inode = filp->f_dentry->d_inode;
 
-	poll_wait(filp, PIPE_WAIT(*inode), wait);
+	poll_wait(filp, PIPE_WAIT_POLL(*inode), wait);
 
 	/* Reading only -- no need for aquiring the semaphore.  */
 	mask = POLLIN | POLLRDNORM;
@@ -296,7 +308,7 @@
 	unsigned int mask;
 	struct inode *inode = filp->f_dentry->d_inode;
 
-	poll_wait(filp, PIPE_WAIT(*inode), wait);
+	poll_wait(filp, PIPE_WAIT_POLL(*inode), wait);
 
 	/* Reading only -- no need for aquiring the semaphore.  */
 	mask = POLLIN | POLLRDNORM;
@@ -337,7 +349,7 @@
 	struct inode *inode = filp->f_dentry->d_inode;
 	unsigned int mask = 0;
 
-	poll_wait(filp, PIPE_WAIT(*inode), wait);
+	poll_wait(filp, PIPE_WAIT_POLL(*inode), wait);
 
 	/* Reading only -- no need for aquiring the semaphore.  */
 	if (!PIPE_EMPTY(*inode)) {
@@ -363,7 +375,9 @@
 		free_page((unsigned long) info->base);
 		kfree(info);
 	} else {
-		wake_up_interruptible(PIPE_WAIT(*inode));
+		wake_up_interruptible(PIPE_WAIT_READ(*inode));
+		wake_up_interruptible(PIPE_WAIT_WRITE(*inode));
+		wake_up_interruptible(PIPE_WAIT_POLL(*inode));
 	}
 	up(PIPE_SEM(*inode));
 
@@ -548,7 +562,9 @@
 
 	inode->i_op = &pipe_inode_operations;
 
-	init_waitqueue_head(PIPE_WAIT(*inode));
+	init_waitqueue_head(PIPE_WAIT_READ(*inode));
+	init_waitqueue_head(PIPE_WAIT_WRITE(*inode));
+	init_waitqueue_head(PIPE_WAIT_POLL(*inode));
 	PIPE_BASE(*inode) = (char *) page;
 	PIPE_START(*inode) = PIPE_LEN(*inode) = 0;
 	PIPE_READERS(*inode) = PIPE_WRITERS(*inode) = 1;
--- linux/fs/fifo.c.orig2	Wed Sep 29 12:10:13 1999
+++ linux/fs/fifo.c	Wed Sep 29 12:20:06 1999
@@ -37,7 +37,9 @@
 
 		inode->i_pipe = info;
 
-		init_waitqueue_head(PIPE_WAIT(*inode));
+		init_waitqueue_head(PIPE_WAIT_READ(*inode));
+		init_waitqueue_head(PIPE_WAIT_WRITE(*inode));
+		init_waitqueue_head(PIPE_WAIT_POLL(*inode));
 		PIPE_BASE(*inode) = (char *) page;
 		PIPE_START(*inode) = PIPE_LEN(*inode) = 0;
 		PIPE_READERS(*inode) = PIPE_WRITERS(*inode) = 0;
@@ -51,15 +53,15 @@
 	 *  opened, even when there is no process writing the FIFO.
 	 */
 		filp->f_op = &connecting_fifo_fops;
-		if (PIPE_READERS(*inode)++ == 0)
-			wake_up_interruptible(PIPE_WAIT(*inode));
+		if (!PIPE_READERS(*inode)++)
+			wake_up_pipe(inode, PIPE_WAIT_WRITE(*inode));
 
 		if (!(filp->f_flags & O_NONBLOCK)) {
 			while (!PIPE_WRITERS(*inode)) {
 				if (signal_pending(current))
 					goto err_rd;
 				up(PIPE_SEM(*inode));
-				interruptible_sleep_on(PIPE_WAIT(*inode));
+				interruptible_sleep_on(PIPE_WAIT_READ(*inode));
 
 				/* Note that using down_interruptible here
 				   and similar places below is pointless,
@@ -85,13 +87,13 @@
 
 		filp->f_op = &write_fifo_fops;
 		if (!PIPE_WRITERS(*inode)++)
-			wake_up_interruptible(PIPE_WAIT(*inode));
+			wake_up_pipe(inode, PIPE_WAIT_READ(*inode));
 
 		while (!PIPE_READERS(*inode)) {
 			if (signal_pending(current))
 				goto err_wr;
 			up(PIPE_SEM(*inode));
-			interruptible_sleep_on(PIPE_WAIT(*inode));
+			interruptible_sleep_on(PIPE_WAIT_WRITE(*inode));
 			down(PIPE_SEM(*inode));
 		}
 		break;
@@ -107,8 +109,11 @@
 
 		PIPE_READERS(*inode)++;
 		PIPE_WRITERS(*inode)++;
-		if (PIPE_READERS(*inode) == 1 || PIPE_WRITERS(*inode) == 1)
-			wake_up_interruptible(PIPE_WAIT(*inode));
+		if (PIPE_READERS(*inode) == 1 || PIPE_WRITERS(*inode) == 1) {
+			wake_up_interruptible(PIPE_WAIT_READ(*inode));
+			wake_up_interruptible(PIPE_WAIT_WRITE(*inode));
+			wake_up_interruptible(PIPE_WAIT_POLL(*inode));
+		}
 		break;
 
 	default:
@@ -122,13 +127,13 @@
 
 err_rd:
 	if (!--PIPE_READERS(*inode))
-		wake_up_interruptible(PIPE_WAIT(*inode));
+		wake_up_pipe(inode, PIPE_WAIT_WRITE(*inode));
 	ret = -ERESTARTSYS;
 	goto err;
 
 err_wr:
 	if (!--PIPE_WRITERS(*inode))
-		wake_up_interruptible(PIPE_WAIT(*inode));
+		wake_up_pipe(inode, PIPE_WAIT_READ(*inode));
 	ret = -ERESTARTSYS;
 	goto err;
 
--- linux/include/linux/wait.h.orig2	Wed Sep 29 12:07:24 1999
+++ linux/include/linux/wait.h	Wed Sep 29 12:23:41 1999
@@ -20,7 +20,7 @@
  * Temporary debugging help until all code is converted to the new
  * waitqueue usage.
  */
-#define WAITQUEUE_DEBUG 0
+#define WAITQUEUE_DEBUG 1
 
 #if WAITQUEUE_DEBUG
 extern int printk(const char *fmt, ...);
--- linux/include/linux/pipe_fs_i.h.orig2	Wed Sep 29 11:52:00 1999
+++ linux/include/linux/pipe_fs_i.h	Wed Sep 29 12:12:38 1999
@@ -2,7 +2,9 @@
 #define _LINUX_PIPE_FS_I_H
 
 struct pipe_inode_info {
-	wait_queue_head_t wait;
+	wait_queue_head_t read_wait;
+	wait_queue_head_t write_wait;
+	wait_queue_head_t poll_wait;
 	char *base;
 	unsigned int start;
 	unsigned int readers;
@@ -14,7 +16,9 @@
 #define PIPE_SIZE		PAGE_SIZE
 
 #define PIPE_SEM(inode)		(&(inode).i_sem)
-#define PIPE_WAIT(inode)	(&(inode).i_pipe->wait)
+#define PIPE_WAIT_READ(inode)	(&(inode).i_pipe->read_wait)
+#define PIPE_WAIT_WRITE(inode)	(&(inode).i_pipe->write_wait)
+#define PIPE_WAIT_POLL(inode)	(&(inode).i_pipe->poll_wait)
 #define PIPE_BASE(inode)	((inode).i_pipe->base)
 #define PIPE_START(inode)	((inode).i_pipe->start)
 #define PIPE_LEN(inode)		((inode).i_size)
@@ -27,5 +31,12 @@
 #define PIPE_END(inode)	((PIPE_START(inode) + PIPE_LEN(inode)) & (PIPE_SIZE-1))
 #define PIPE_MAX_RCHUNK(inode)	(PIPE_SIZE - PIPE_START(inode))
 #define PIPE_MAX_WCHUNK(inode)	(PIPE_SIZE - PIPE_END(inode))
+
+#define wake_up_pipe(inode,wq) \
+do { \
+	wake_up_interruptible(wq); \
+	if (waitqueue_active(PIPE_WAIT_POLL(*(inode)))) \
+		wake_up_interruptible(PIPE_WAIT_POLL(*(inode))); \
+} while (0)
 
 #endif