ust: make lttd work

[ust.git] / libtracing / relay.h

diff --git a/libtracing/relay.h b/libtracing/relay.h
index 6cfcb077578ac20c42fc07a2a3eeb524402e22f9..cd3baae3f3d180c81dcc585e8d89c1c89e3772e6 100644 (file)
--- a/libtracing/relay.h
+++ b/libtracing/relay.h
@@ -345,10 +345,14 @@ struct ltt_channel_buf_struct {
 //ust//                                         * writers
 //ust//                                         */
 //ust//        atomic_t wakeup_readers;        /* Boolean : wakeup readers waiting ? */
-       /* whether or not wake_consumer must be called; must be accessed atomically */
-       int call_wake_consumer;
-       /* the arg to pass to wake_consumer; must be accessed atomically */
-       void *wake_consumer_arg;
+       /* one byte is written to this pipe when data is available, in order
+           to wake the consumer */
+       /* portability: Single byte writes must be as quick as possible. The kernel-side
+          buffer must be large enough so the writer doesn't block. From the pipe(7)
+           man page: Since linux 2.6.11, the pipe capacity is 65536 bytes. */
+       int data_ready_fd_write;
+       /* the reading end of the pipe */
+       int data_ready_fd_read;
 } ____cacheline_aligned;
 
 int ltt_do_get_subbuf(struct rchan_buf *buf, struct ltt_channel_buf_struct *ltt_buf, long *pconsumed_old);