X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=libust%2Fbuffers.h;h=4fa6262af1715da97ebd69afecfa4084d61566dd;hb=6a843332a8ac7d1125e0961f148cc494e0397923;hp=2dcc9245967a2315c07fe871463a2b5c71d19bb0;hpb=dc2848112a55ee60632491148089cc60984f683d;p=ust.git

diff --git a/libust/buffers.h b/libust/buffers.h
index 2dcc924..4fa6262 100644
--- a/libust/buffers.h
+++ b/libust/buffers.h
@@ -1,21 +1,37 @@
 /*
  * buffers.h
+ * LTTng userspace tracer buffering system
  *
  * Copyright (C) 2009 - Pierre-Marc Fournier (pierre-marc dot fournier at polymtl dot ca)
  * Copyright (C) 2008 - Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca)
  *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  */
 
 #ifndef _UST_BUFFERS_H
 #define _UST_BUFFERS_H
 
-#include <kcompat/kref.h>
 #include <assert.h>
+
+#include <ust/core.h>
+
+#include "usterr.h"
 #include "channels.h"
 #include "tracerconst.h"
 #include "tracercore.h"
 #include "header-inline.h"
-#include <usterr.h>
 
 /***** FIXME: SHOULD BE REMOVED ***** */
 
@@ -90,10 +106,12 @@ struct ust_buffer {
  */
 enum force_switch_mode { FORCE_ACTIVE, FORCE_FLUSH };
 
-extern int ltt_reserve_slot_lockless_slow(struct ust_trace *trace,
-		struct ust_channel *ltt_channel, void **transport_data,
-		size_t data_size, size_t *slot_size, long *buf_offset, u64 *tsc,
-		unsigned int *rflags, int largest_align, int cpu);
+extern int ltt_reserve_slot_lockless_slow(struct ust_channel *chan,
+		struct ust_trace *trace, size_t data_size,
+		int largest_align, int cpu,
+		struct ust_buffer **ret_buf,
+		size_t *slot_size, long *buf_offset,
+		u64 *tsc, unsigned int *rflags);
 
 extern void ltt_force_switch_lockless_slow(struct ust_buffer *buf,
 		enum force_switch_mode mode);
@@ -337,19 +355,21 @@ static __inline__ int ltt_relay_try_reserve(
 	return 0;
 }
 
-static __inline__ int ltt_reserve_slot(struct ust_trace *trace,
-		struct ust_channel *chan, void **transport_data,
-		size_t data_size, size_t *slot_size, long *buf_offset, u64 *tsc,
-		unsigned int *rflags, int largest_align, int cpu)
+static __inline__ int ltt_reserve_slot(struct ust_channel *chan,
+				       struct ust_trace *trace, size_t data_size,
+				       int largest_align, int cpu,
+				       struct ust_buffer **ret_buf,
+				       size_t *slot_size, long *buf_offset, u64 *tsc,
+				       unsigned int *rflags)
 {
-	struct ust_buffer *buf = chan->buf[cpu];
+	struct ust_buffer *buf = *ret_buf = chan->buf[cpu];
 	long o_begin, o_end, o_old;
 	size_t before_hdr_pad;
 
 	/*
 	 * Perform retryable operations.
 	 */
-	/* FIXME: make this rellay per cpu? */
+	/* FIXME: make this really per cpu? */
 	if (unlikely(LOAD_SHARED(ltt_nesting) > 4)) {
 		DBG("Dropping event because nesting is too deep.");
 		uatomic_inc(&buf->events_lost);
@@ -386,9 +406,10 @@ static __inline__ int ltt_reserve_slot(struct ust_trace *trace,
 	*buf_offset = o_begin + before_hdr_pad;
 	return 0;
 slow_path:
-	return ltt_reserve_slot_lockless_slow(trace, chan,
-		transport_data, data_size, slot_size, buf_offset, tsc,
-		rflags, largest_align, cpu);
+	return ltt_reserve_slot_lockless_slow(chan, trace, data_size,
+					      largest_align, cpu, ret_buf,
+					      slot_size, buf_offset, tsc,
+					      rflags);
 }
 
 /*
@@ -462,16 +483,8 @@ static __inline__ void ltt_commit_slot(
 	long endidx = SUBBUF_INDEX(offset_end - 1, chan);
 	long commit_count;
 
-#ifdef LTT_NO_IPI_BARRIER
 	smp_wmb();
-#else
-	/*
-	 * Must write slot data before incrementing commit count.
-	 * This compiler barrier is upgraded into a smp_mb() by the IPI
-	 * sent by get_subbuf().
-	 */
-	barrier();
-#endif
+
 	uatomic_add(&buf->commit_count[endidx].cc, slot_size);
 	/*
 	 * commit count read can race with concurrent OOO commit count updates.