Merge branch 'perf/core' into perf/uprobes

Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 31 insertions, 6 deletions

diff --git a/include/linux/poll.h b/include/linux/poll.h
index cf40010ce0c..48fe8bc398d 100644
--- a/include/linux/poll.h
+++ b/include/linux/poll.h
@@ -32,21 +32,46 @@ struct poll_table_struct;
  */
 typedef void (*poll_queue_proc)(struct file *, wait_queue_head_t *, struct poll_table_struct *);
 
+/*
+ * Do not touch the structure directly, use the access functions
+ * poll_does_not_wait() and poll_requested_events() instead.
+ */
 typedef struct poll_table_struct {
-	poll_queue_proc qproc;
-	unsigned long key;
+	poll_queue_proc _qproc;
+	unsigned long _key;
 } poll_table;
 
 static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p)
 {
-	if (p && wait_address)
-		p->qproc(filp, wait_address, p);
+	if (p && p->_qproc && wait_address)
+		p->_qproc(filp, wait_address, p);
+}
+
+/*
+ * Return true if it is guaranteed that poll will not wait. This is the case
+ * if the poll() of another file descriptor in the set got an event, so there
+ * is no need for waiting.
+ */
+static inline bool poll_does_not_wait(const poll_table *p)
+{
+	return p == NULL || p->_qproc == NULL;
+}
+
+/*
+ * Return the set of events that the application wants to poll for.
+ * This is useful for drivers that need to know whether a DMA transfer has
+ * to be started implicitly on poll(). You typically only want to do that
+ * if the application is actually polling for POLLIN and/or POLLOUT.
+ */
+static inline unsigned long poll_requested_events(const poll_table *p)
+{
+	return p ? p->_key : ~0UL;
 }
 
 static inline void init_poll_funcptr(poll_table *pt, poll_queue_proc qproc)
 {
-	pt->qproc = qproc;
-	pt->key   = ~0UL; /* all events enabled */
+	pt->_qproc = qproc;
+	pt->_key   = ~0UL; /* all events enabled */
 }
 
 struct poll_table_entry {