#include <common/common.h>
#include <common/defaults.h>
#include <common/trace-chunk.h>
+#include <common/macros.h>
#include "consumer.h"
#include "trace-kernel.h"
*/
struct ltt_kernel_metadata *trace_kernel_create_metadata(void)
{
+ int ret;
struct ltt_kernel_metadata *lkm;
struct lttng_channel *chan;
goto error;
}
+ ret = lttng_strncpy(
+ chan->name, DEFAULT_METADATA_NAME, sizeof(chan->name));
+ if (ret) {
+ ERR("Failed to initialize metadata channel name to `%s`",
+ DEFAULT_METADATA_NAME);
+ goto error;
+ }
+
/* Set default attributes */
- chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
+ chan->attr.overwrite = DEFAULT_METADATA_OVERWRITE;
chan->attr.subbuf_size = default_get_metadata_subbuf_size();
chan->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
- chan->attr.switch_timer_interval = DEFAULT_KERNEL_CHANNEL_SWITCH_TIMER;
- chan->attr.read_timer_interval = DEFAULT_KERNEL_CHANNEL_READ_TIMER;
- chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
+ chan->attr.switch_timer_interval = DEFAULT_METADATA_SWITCH_TIMER;
+ chan->attr.read_timer_interval = DEFAULT_METADATA_READ_TIMER;;
+
+
+ /*
+ * The metadata channel of kernel sessions must use the "mmap"
+ * back-end since the consumer daemon accumulates complete
+ * metadata units before sending them to the relay daemon in
+ * live mode. The consumer daemon also needs to extract the contents
+ * of the metadata cache when computing a rotation position.
+ *
+ * In both cases, it is not possible to rely on the splice
+ * back-end as the consumer daemon may need to accumulate more
+ * content than can be backed by the ring buffer's underlying
+ * pages.
+ */
+ chan->attr.output = LTTNG_EVENT_MMAP;
+ chan->attr.tracefile_size = 0;
+ chan->attr.tracefile_count = 0;
+ chan->attr.live_timer_interval = 0;
/* Init metadata */
lkm->fd = -1;