#include "ust/ustconsumer.h"
#include "buffers.h"
#include "tracer.h"
-#include "usterr.h"
+#include "usterr_signal_safe.h"
/* This truncates to an offset in the buffer. */
#define USTD_BUFFER_TRUNC(offset, bufinfo) \
#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.
*
void finish_consuming_dead_subbuffer(struct ustconsumer_callbacks *callbacks, struct buffer_info *buf)
{
- struct ust_buffer *ustbuf = buf->bufstruct_mem;
-
- long write_offset = uatomic_read(&ustbuf->offset);
- long consumed_offset = uatomic_read(&ustbuf->consumed);
-
- long i_subbuf;
+ struct ust_buffer *ust_buf = buf->bufstruct_mem;
+ unsigned long n_subbufs_order = get_count_order(buf->n_subbufs);
+ unsigned long commit_seq_mask = (~0UL >> n_subbufs_order);
+ unsigned long cons_off;
+ int ret;
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. */
- long first_subbuf = consumed_offset / buf->subbuf_size;
- /* Last subbuf that we need to consume now. It is not modulo'd.
- * Write_offset is the next place to write so write_offset-1 is the
- * last place written. */
- long last_subbuf = (write_offset - 1) / buf->subbuf_size;
-
- DBG("first_subbuf=%ld", first_subbuf);
- DBG("last_subbuf=%ld", last_subbuf);
-
- if(last_subbuf - first_subbuf >= buf->n_subbufs) {
- DBG("an overflow has occurred, nothing can be recovered");
- return;
- }
-
- /* Iterate on subbuffers to recover. */
- for(i_subbuf = first_subbuf % buf->n_subbufs; ; i_subbuf++, i_subbuf %= buf->n_subbufs) {
- /* 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. */
- long commit_seq = uatomic_read(&ustbuf->commit_seq[i_subbuf]);
-
- unsigned long valid_length = buf->subbuf_size;
- long n_subbufs_order = get_count_order(buf->n_subbufs);
- long commit_seq_mask = (~0UL >> n_subbufs_order);
-
- 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;
- }
+ DBG("consumed offset is %ld (%s)", uatomic_read(&ust_buf->consumed),
+ buf->name);
+ DBG("write offset is %ld (%s)", uatomic_read(&ust_buf->offset),
+ buf->name);
+
+ /*
+ * Iterate on subbuffers to recover, including the one the writer
+ * just wrote data into. Using write position - 1 since the writer
+ * position points into the position that is going to be written.
+ */
+ for (cons_off = uatomic_read(&ust_buf->consumed);
+ (long) (SUBBUF_TRUNC(uatomic_read(&ust_buf->offset) - 1, buf)
+ - cons_off) >= 0;
+ cons_off = SUBBUF_ALIGN(cons_off, buf)) {
+ /*
+ * 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.
+ */
+ unsigned long commit_seq =
+ uatomic_read(&ust_buf->commit_seq[SUBBUF_INDEX(cons_off, buf)]);
+ struct ltt_subbuffer_header *header =
+ (struct ltt_subbuffer_header *)((char *) buf->mem
+ + SUBBUF_INDEX(cons_off, buf) * buf->subbuf_size);
+ unsigned long valid_length;
/* 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. */
+ - (USTD_BUFFER_TRUNC(uatomic_read(&ust_buf->consumed), buf) >> n_subbufs_order) == 0
+ && header->data_size != 0xffffffff) {
+ assert(header->sb_size != 0xffffffff);
+ /*
+ * If it was fully written, 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 (%ld) with valid_length = %ld", i_subbuf, valid_length);
- }
- else {
- /* If the subbuffer was not fully written, then we don't check data_size because
- * it hasn't been written yet. Instead we check commit_seq and use it to choose
- * a value for data_size. The viewer will need this value when parsing.
+ DBG("writing full subbuffer (%ld) with valid_length = %ld",
+ SUBBUF_INDEX(cons_off, buf), valid_length);
+ } else {
+ /*
+ * If the subbuffer was not fully written, then we don't
+ * check data_size because it hasn't been written yet.
+ * Instead we check commit_seq and use it to choose a
+ * value for data_size. The viewer will need this value
+ * when parsing. Generally, this will happen only for
+ * the last subbuffer. However, if we have threads still
+ * holding reserved slots in the previous subbuffers,
+ * which could happen for other subbuffers prior to the
+ * last one. Note that when data_size is set, the
+ * commit_seq count is still at a value that shows the
+ * amount of valid data to read. It's only _after_
+ * writing data_size that commit_seq is updated to
+ * include the end-of-buffer padding.
*/
-
- valid_length = commit_seq & (buf->subbuf_size-1);
- DBG("writing unfull subbuffer (%ld) with valid_length = %ld", i_subbuf, valid_length);
+ valid_length = commit_seq & (buf->subbuf_size - 1);
+ DBG("writing unfull subbuffer (%ld) with valid_length = %ld",
+ SUBBUF_INDEX(cons_off, buf), valid_length);
header->data_size = valid_length;
header->sb_size = PAGE_ALIGN(valid_length);
- assert(i_subbuf == (last_subbuf % buf->n_subbufs));
}
- /* TODO: check on_read_partial_subbuffer return value */
- if(callbacks->on_read_partial_subbuffer)
- callbacks->on_read_partial_subbuffer(callbacks, buf, i_subbuf, valid_length);
-
- if(i_subbuf == last_subbuf % buf->n_subbufs)
- break;
+ if (callbacks->on_read_partial_subbuffer) {
+ ret = callbacks->on_read_partial_subbuffer(callbacks, buf,
+ SUBBUF_INDEX(cons_off, buf),
+ valid_length);
+ if (ret < 0)
+ break; /* Error happened */
+ }
}
+ /* Increment the consumed offset */
+ uatomic_set(&ust_buf->consumed, cons_off);
+ ltt_relay_print_buffer_errors(buf, buf->channel_cpu);
}
projects / ust.git / blobdiff