X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=ustd%2Flowlevel.c;h=4c179c5cbe1317b71b6724f276fcd920cdee4ac8;hb=1d59f7ebe74e0bb11f5db359e543f8f05a2f8635;hp=d8d4cfa32c80cc83c1f11d456d24016ac6365289;hpb=02af3e607f471e9fcfe7ea6902cab56efb4c4516;p=ust.git

diff --git a/ustd/lowlevel.c b/ustd/lowlevel.c
index d8d4cfa..4c179c5 100644
--- a/ustd/lowlevel.c
+++ b/ustd/lowlevel.c
@@ -70,9 +70,9 @@ void finish_consuming_dead_subbuffer(struct buffer_info *buf)
 
 	long i_subbuf;
 
-	DBG("processing died buffer");
-	DBG("consumed offset is %ld", consumed_offset);
-	DBG("write offset is %ld", write_offset);
+	DBG("processing dead buffer (%s)", buf->name);
+	DBG("consumed offset is %ld (%s)", consumed_offset, buf->name);
+	DBG("write offset is %ld (%s)", write_offset, buf->name);
 
 	/* First subbuf that we need to consume now. It is not modulo'd.
 	 * Consumed_offset is the next byte to consume.  */
@@ -91,7 +91,7 @@ void finish_consuming_dead_subbuffer(struct buffer_info *buf)
 	}
 
 	/* Iterate on subbuffers to recover. */
-	for(i_subbuf=first_subbuf; ; i_subbuf++, i_subbuf %= buf->n_subbufs) {
+	for(i_subbuf = first_subbuf % buf->n_subbufs; ; i_subbuf++, i_subbuf %= buf->n_subbufs) {
 		void *tmp;
 		/* commit_seq is the offset in the buffer of the end of the last sequential commit.
 		 * Bytes beyond this limit cannot be recovered. This is a free-running counter. */
@@ -112,12 +112,15 @@ void finish_consuming_dead_subbuffer(struct buffer_info *buf)
 		}
 
 		/* 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 */
 		if (((commit_seq - buf->subbuf_size) & commit_seq_mask)
 		    - (USTD_BUFFER_TRUNC(consumed_offset, buf) >> n_subbufs_order) == 0
                     && header->data_size != 0xffffffff && header->sb_size != 0xffffffff) {
 			/* If it was, we only check the data_size. This is the amount of valid data at
 			 * the beginning of the subbuffer. */
 			valid_length = header->data_size;
+			DBG("writing full subbuffer (%d) with valid_length = %ld", i_subbuf, valid_length);
 		}
 		else {
 			/* If the subbuffer was not fully written, then we don't check data_size because
@@ -126,6 +129,7 @@ void finish_consuming_dead_subbuffer(struct buffer_info *buf)
 			 */
 
 			valid_length = commit_seq & (buf->subbuf_size-1);
+			DBG("writing unfull subbuffer (%d) with valid_length = %ld", i_subbuf, valid_length);
 			header->data_size = valid_length;
 			header->sb_size = PAGE_ALIGN(valid_length);
 			assert(i_subbuf == (last_subbuf % buf->n_subbufs));