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authorIngo Molnar <mingo@kernel.org>2012-04-13 09:50:21 +0200
committerIngo Molnar <mingo@kernel.org>2012-04-13 09:50:21 +0200
commit659c36fcda403013a01b85da07cf2d9711e6d6c7 (patch)
treeece2e7d0e2c19ea5a3d0ec172ad0b81a8a19021d /include/linux/poll.h
parent9521d830b6341d1887dcfc2aebde23fbfa5f1473 (diff)
parent5a7ed29c7572d00a75e8c4529e30c5ac2ef82271 (diff)
Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core
Fixes and improvements for perf/core: . Overhaul the tools/ makefiles, gluing them to the top level Makefile, from Borislav Petkov. . Move the UI files from tools/perf/util/ui/ to tools/perf/ui/. Also move the GTK+ browser to tools/perf/ui/gtk/, from Namhyung Kim. . Only fallback to sw cycles counter on ENOENT for the hw cycles, from Robert Richter . Trivial fixes from Robert Richter . Handle the autogenerated bison/flex files better, from Namhyung and Jiri Olsa. . Navigate jump instructions in the annotate browser, just press enter or ->, still needs support for a jump navigation history, i.e. to go back. . Search string in the annotate browser: same keys as vim: / forward n next backward/forward ? backward . Clarify number of events/samples in the report header, from Ashay Rane Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/poll.h')
-rw-r--r--include/linux/poll.h37
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 {