Packet headers and alignment

[lttng-modules.git] / ltt-tracer.h

diff --git a/ltt-tracer.h b/ltt-tracer.h
index 3bb55234aa5bea4bb2ff704a117fa06754c7668b..f1cd2d90f75e4d258f335c400a6c0aa759c9533c 100644 (file)
--- a/ltt-tracer.h
+++ b/ltt-tracer.h
@@ -113,66 +113,29 @@ struct event_header {
 
 #define LTT_MAX_SMALL_SIZE             0xFFFFU
 
+#ifdef RING_BUFFER_ALIGN
 static inline
 size_t ltt_get_header_alignment(void)
 {
-#ifdef RING_BUFFER_ALIGN
        return sizeof(struct event_header) * CHAR_BIT;
+}
+
+#define ltt_alignof(type)      __alignof__(type)
 #else
+static inline
+size_t ltt_get_header_alignment(void)
+{
        return CHAR_BIT;
-#endif
 }
 
-/*
- * We use asm/timex.h : cpu_khz/HZ variable in here : we might have to deal
- * specifically with CPU frequency scaling someday, so using an interpolation
- * between the start and end of buffer values is not flexible enough. Using an
- * immediate frequency value permits to calculate directly the times for parts
- * of a buffer that would be before a frequency change.
- *
- * Keep the natural field alignment for _each field_ within this structure if
- * you ever add/remove a field from this header. Packed attribute is not used
- * because gcc generates poor code on at least powerpc and mips. Don't ever
- * let gcc add padding between the structure elements.
- */
-struct packet_header {
-       uint32_t magic;                 /*
-                                        * Trace magic number.
-                                        * contains endianness information.
-                                        */
-       uint8_t trace_uuid[16];
-       uint32_t stream_id;
-       uint64_t timestamp_begin;       /* Cycle count at subbuffer start */
-       uint64_t timestamp_end; /* Cycle count at subbuffer end */
-       uint32_t content_size;          /* Size of data in subbuffer */
-       uint32_t packet_size;           /* Subbuffer size (include padding) */
-       uint32_t events_lost;           /*
-                                        * Events lost in this subbuffer since
-                                        * the beginning of the trace.
-                                        * (may overflow)
-                                        */
-       /* TODO: move to metadata */
-#if 0
-       uint8_t major_version;
-       uint8_t minor_version;
-       uint8_t arch_size;              /* Architecture pointer size */
-       uint8_t alignment;              /* LTT data alignment */
-       uint64_t start_time_sec;        /* NTP-corrected start time */
-       uint64_t start_time_usec;
-       uint64_t start_freq;            /*
-                                        * Frequency at trace start,
-                                        * used all along the trace.
-                                        */
-       uint32_t freq_scale;            /* Frequency scaling (divisor) */
-#endif //0
-       uint8_t header_end[0];          /* End of header */
-};
+#define ltt_alignof(type)      1
+#endif
 
 /* Tracer properties */
 #define CTF_MAGIC_NUMBER               0xC1FC1FC1
 #define TSDL_MAGIC_NUMBER              0x75D11D57
-#define LTT_TRACER_VERSION_MAJOR       3
-#define LTT_TRACER_VERSION_MINOR       0
+#define CTF_VERSION_MAJOR              0
+#define CTF_VERSION_MINOR              1
 
 /*
  * Number of milliseconds to retry before failing metadata writes on buffer full