[ltt-dev] [UST PATCH] Code base to fix the print errors in UST (v4)

Yannick Brosseau yannick.brosseau at gmail.com
Thu Mar 3 10:40:08 EST 2011


From: David Goulet <david.goulet at polymtl.ca>

Update:
v2: Use commit_seq instead of commit_count to fix a consumerd segfault when accessing
commit_count, since it is not mapped.
v3: Remove commented out code
v4: Remove unused variable

Signed-off-by: Yannick Brosseau <yannick.brosseau at gmail.com>
Signed-off-by: David Goulet <david.goulet at polymtl.ca>
---
 include/ust/ustconsumer.h       |    4 ++
 libust/buffers.c                |   82 ---------------------------------------
 libustconsumer/libustconsumer.c |    4 ++
 libustconsumer/lowlevel.c       |   72 +++++++++++++++++++++++++++++++---
 4 files changed, 74 insertions(+), 88 deletions(-)

diff --git a/include/ust/ustconsumer.h b/include/ust/ustconsumer.h
index e07b75e..f99f8f1 100644
--- a/include/ust/ustconsumer.h
+++ b/include/ust/ustconsumer.h
@@ -57,6 +57,10 @@ struct buffer_info {
 	int n_subbufs;
 	/* size of each subbuffer */
 	int subbuf_size;
+	/* subbuf size count order */
+	int subbuf_size_order;
+	/* alloc size of all subbuf */
+	int alloc_size;
 
 	/* the buffer information struct */
 	void *bufstruct_mem;
diff --git a/libust/buffers.c b/libust/buffers.c
index 4011b64..732e03d 100644
--- a/libust/buffers.c
+++ b/libust/buffers.c
@@ -254,12 +254,8 @@ unmap_buf:
 	return -1;
 }
 
-static void ltt_relay_print_buffer_errors(struct ust_channel *chan, int cpu);
-
 static void close_buf(struct ust_buffer *buf)
 {
-	struct ust_channel *chan = buf->chan;
-	int cpu = buf->cpu;
 	int result;
 
 	result = shmdt(buf->buf_data);
@@ -267,8 +263,6 @@ static void close_buf(struct ust_buffer *buf)
 		PERROR("shmdt");
 	}
 
-	free(buf->commit_count);
-
 	result = close(buf->data_ready_fd_read);
 	if (result < 0) {
 		PERROR("close");
@@ -278,9 +272,6 @@ static void close_buf(struct ust_buffer *buf)
 	if (result < 0 && errno != EBADF) {
 		PERROR("close");
 	}
-
-	/* FIXME: This spews out errors, are they real?:
-	 * ltt_relay_print_buffer_errors(chan, cpu); */
 }
 
 
@@ -517,78 +508,6 @@ int ust_buffers_put_subbuf(struct ust_buffer *buf, unsigned long uconsumed_old)
 	return 0;
 }
 
-static void ltt_relay_print_subbuffer_errors(
-		struct ust_channel *channel,
-		long cons_off, int cpu)
-{
-	struct ust_buffer *ltt_buf = channel->buf[cpu];
-	long cons_idx, commit_count, commit_count_sb, write_offset;
-
-	cons_idx = SUBBUF_INDEX(cons_off, channel);
-	commit_count = uatomic_read(&ltt_buf->commit_count[cons_idx].cc);
-	commit_count_sb = uatomic_read(&ltt_buf->commit_count[cons_idx].cc_sb);
-
-	/*
-	 * No need to order commit_count and write_offset reads because we
-	 * execute after trace is stopped when there are no readers left.
-	 */
-	write_offset = uatomic_read(&ltt_buf->offset);
-	WARN( "LTT : unread channel %s offset is %ld "
-		"and cons_off : %ld (cpu %d)\n",
-		channel->channel_name, write_offset, cons_off, cpu);
-	/* Check each sub-buffer for non filled commit count */
-	if (((commit_count - channel->subbuf_size) & channel->commit_count_mask)
-	    - (BUFFER_TRUNC(cons_off, channel) >> channel->n_subbufs_order) != 0) {
-		ERR("LTT : %s : subbuffer %lu has non filled "
-			"commit count [cc, cc_sb] [%lu,%lu].\n",
-			channel->channel_name, cons_idx, commit_count, commit_count_sb);
-	}
-	ERR("LTT : %s : commit count : %lu, subbuf size %zd\n",
-			channel->channel_name, commit_count,
-			channel->subbuf_size);
-}
-
-static void ltt_relay_print_errors(struct ust_trace *trace,
-		struct ust_channel *channel, int cpu)
-{
-	struct ust_buffer *ltt_buf = channel->buf[cpu];
-	long cons_off;
-
-	/*
-	 * Can be called in the error path of allocation when
-	 * trans_channel_data is not yet set.
-	 */
-	if (!channel)
-	        return;
-
-//ust//	for (cons_off = 0; cons_off < rchan->alloc_size;
-//ust//	     cons_off = SUBBUF_ALIGN(cons_off, rchan))
-//ust//		ust_buffers_print_written(ltt_chan, cons_off, cpu);
-	for (cons_off = uatomic_read(&ltt_buf->consumed);
-			(SUBBUF_TRUNC(uatomic_read(&ltt_buf->offset),
-				      channel)
-			 - cons_off) > 0;
-			cons_off = SUBBUF_ALIGN(cons_off, channel))
-		ltt_relay_print_subbuffer_errors(channel, cons_off, cpu);
-}
-
-static void ltt_relay_print_buffer_errors(struct ust_channel *channel, int cpu)
-{
-	struct ust_trace *trace = channel->trace;
-	struct ust_buffer *ltt_buf = channel->buf[cpu];
-
-	if (uatomic_read(&ltt_buf->events_lost))
-		ERR("channel %s: %ld events lost (cpu %d)",
-			channel->channel_name,
-			uatomic_read(&ltt_buf->events_lost), cpu);
-	if (uatomic_read(&ltt_buf->corrupted_subbuffers))
-		ERR("channel %s : %ld corrupted subbuffers (cpu %d)",
-			channel->channel_name,
-			uatomic_read(&ltt_buf->corrupted_subbuffers), cpu);
-
-	ltt_relay_print_errors(trace, channel, cpu);
-}
-
 static int map_buf_structs(struct ust_channel *chan)
 {
 	void *ptr;
@@ -721,7 +640,6 @@ static void remove_channel(struct ust_channel *chan)
 	free(chan->buf_struct_shmids);
 
 	free(chan->buf);
-
 }
 
 static void ltt_relay_async_wakeup_chan(struct ust_channel *ltt_channel)
diff --git a/libustconsumer/libustconsumer.c b/libustconsumer/libustconsumer.c
index c51b106..ef54fe8 100644
--- a/libustconsumer/libustconsumer.c
+++ b/libustconsumer/libustconsumer.c
@@ -353,6 +353,10 @@ struct buffer_info *connect_buffer(struct ustconsumer_instance *instance, pid_t
 		goto close_fifo;
 	}
 
+	/* Set subbuffer's information */
+	buf->subbuf_size_order = get_count_order(buf->subbuf_size);
+	buf->alloc_size = buf->subbuf_size * buf->n_subbufs;
+
 	/* attach memory */
 	buf->mem = shmat(buf->shmid, NULL, 0);
 	if(buf->mem == (void *) 0) {
diff --git a/libustconsumer/lowlevel.c b/libustconsumer/lowlevel.c
index 730dd11..fdc4e24 100644
--- a/libustconsumer/lowlevel.c
+++ b/libustconsumer/lowlevel.c
@@ -31,6 +31,66 @@
 #define LTT_MAGIC_NUMBER 0x00D6B7ED
 #define LTT_REV_MAGIC_NUMBER 0xEDB7D600
 
+
+static void ltt_relay_print_subbuffer_errors(
+		struct buffer_info *buf,
+		long cons_off, int cpu)
+{
+	struct ust_buffer *ust_buf = buf->bufstruct_mem;
+	long cons_idx, commit_count, commit_count_mask, write_offset;
+
+	cons_idx = SUBBUF_INDEX(cons_off, buf);
+	commit_count = uatomic_read(&ust_buf->commit_seq[cons_idx]);
+	commit_count_mask = (~0UL >> get_count_order(buf->n_subbufs));
+
+	/*
+	 * No need to order commit_count and write_offset reads because we
+	 * execute after trace is stopped when there are no readers left.
+	 */
+	write_offset = uatomic_read(&ust_buf->offset);
+	WARN( "LTT : unread channel %s offset is %ld "
+			"and cons_off : %ld (cpu %d)\n",
+			buf->channel, write_offset, cons_off, cpu);
+	/* Check each sub-buffer for non filled commit count */
+	if (((commit_count - buf->subbuf_size) & commit_count_mask)
+			- (BUFFER_TRUNC(cons_off, buf) >> get_count_order(buf->n_subbufs)) != 0) {
+		ERR("LTT : %s : subbuffer %lu has non filled "
+				"commit count [seq] [%lu].\n",
+				buf->channel, cons_idx, commit_count);
+	}
+	ERR("LTT : %s : commit count : %lu, subbuf size %d\n",
+			buf->channel, commit_count,
+			buf->subbuf_size);
+}
+
+static void ltt_relay_print_errors(struct buffer_info *buf, int cpu)
+{
+	struct ust_buffer *ust_buf = buf->bufstruct_mem;
+	long cons_off;
+
+	for (cons_off = uatomic_read(&ust_buf->consumed);
+			(SUBBUF_TRUNC(uatomic_read(&ust_buf->offset), buf)
+				- cons_off) > 0;
+			cons_off = SUBBUF_ALIGN(cons_off, buf))
+		ltt_relay_print_subbuffer_errors(buf, cons_off, cpu);
+}
+
+static void ltt_relay_print_buffer_errors(struct buffer_info *buf, int cpu)
+{
+	struct ust_buffer *ust_buf = buf->bufstruct_mem;
+
+	if (uatomic_read(&ust_buf->events_lost))
+		ERR("channel %s: %ld events lost (cpu %d)",
+				buf->channel,
+				uatomic_read(&ust_buf->events_lost), cpu);
+	if (uatomic_read(&ust_buf->corrupted_subbuffers))
+		ERR("channel %s : %ld corrupted subbuffers (cpu %d)",
+				buf->channel,
+				uatomic_read(&ust_buf->corrupted_subbuffers), cpu);
+
+	ltt_relay_print_errors(buf, cpu);
+}
+
 /* Returns the size of a subbuffer size. This is the size that
  * will need to be written to disk.
  *
@@ -103,12 +163,6 @@ void finish_consuming_dead_subbuffer(struct ustconsumer_callbacks *callbacks, st
 
 		struct ltt_subbuffer_header *header = (struct ltt_subbuffer_header *)((char *)buf->mem+i_subbuf*buf->subbuf_size);
 
-		if((commit_seq & commit_seq_mask) == 0) {
-			/* There is nothing to do. */
-			/* FIXME: is this needed? */
-			break;
-		}
-
 		/* Check if subbuf was fully written. This is from Mathieu's algorithm/paper. */
 		/* FIXME: not sure data_size = 0xffffffff when the buffer is not full. It might
 		 * take the value of the header size initially */
@@ -137,8 +191,14 @@ void finish_consuming_dead_subbuffer(struct ustconsumer_callbacks *callbacks, st
 		if(callbacks->on_read_partial_subbuffer)
 			callbacks->on_read_partial_subbuffer(callbacks, buf, i_subbuf, valid_length);
 
+		/* Manually increment the consumed offset */
+		/* TODO ybrosseau 2011-03-02: Should only be done if the previous read was successful */
+		uatomic_add(&ustbuf->consumed, buf->subbuf_size);
+
 		if(i_subbuf == last_subbuf % buf->n_subbufs)
 			break;
 	}
+
+	ltt_relay_print_buffer_errors(buf, buf->channel_cpu);
 }
 
-- 
1.7.2.3





More information about the lttng-dev mailing list