Packet headers and alignment
authorMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Sat, 14 May 2011 16:59:11 +0000 (12:59 -0400)
committerMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Sat, 14 May 2011 16:59:11 +0000 (12:59 -0400)
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
ltt-events.c
ltt-events.h
ltt-ring-buffer-client.h
ltt-ring-buffer-metadata-client.h
ltt-tracer.h
probes/lttng-events.h
probes/lttng-types.h

index 1d729210f83049ba3fcc7f5364988afedcfaf901..db1ac86fef6573645fc42edd0ae46f32fcfbd333 100644 (file)
@@ -12,6 +12,7 @@
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/jiffies.h>
+#include <linux/uuid.h>
 #include "wrapper/vmalloc.h"   /* for wrapper_vmalloc_sync_all() */
 #include "ltt-events.h"
 #include "ltt-tracer.h"
@@ -48,6 +49,7 @@ struct ltt_session *ltt_session_create(void)
                return NULL;
        INIT_LIST_HEAD(&session->chan);
        INIT_LIST_HEAD(&session->events);
+       uuid_le_gen(&session->uuid);
        list_add(&session->list, &sessions);
        mutex_unlock(&sessions_mutex);
        return session;
@@ -316,10 +318,11 @@ int lttng_metadata_printf(struct ltt_session *session,
                        ret != -ENOBUFS || !ret;
                }),
                msecs_to_jiffies(LTTNG_METADATA_TIMEOUT_MSEC));
-       if (waitret || ret) {
+       if (!waitret || waitret == -ERESTARTSYS || ret) {
                printk(KERN_WARNING "LTTng: Failure to write metadata to buffers (%s)\n",
                        waitret == -ERESTARTSYS ? "interrupted" :
                                (ret == -ENOBUFS ? "timeout" : "I/O error"));
+               printk("waitret %d retval %d\n", waitret, ret);
                if (waitret == -ERESTARTSYS)
                        ret = waitret;
                goto end;
@@ -459,7 +462,7 @@ int _ltt_event_metadata_statedump(struct ltt_session *session,
         */
        ret = lttng_metadata_printf(session,
                "       } aligned(%u);\n"
-               "};\n", ltt_get_header_alignment());
+               "};\n\n", ltt_get_header_alignment());
        if (ret)
                goto end;
 
@@ -488,7 +491,7 @@ int _ltt_channel_metadata_statedump(struct ltt_session *session,
                "stream {\n"
                "       id = %u;\n"
                "       event.header := %s;\n",
-               "};\n",
+               "};\n\n",
                chan->id,
                chan->header_type == 1 ? "struct event_header_compact" :
                        "struct event_header_large");
@@ -506,6 +509,7 @@ end:
 static
 int _ltt_session_metadata_statedump(struct ltt_session *session)
 {
+       char uuid_s[37];
        struct ltt_channel *chan;
        struct ltt_event *event;
        int ret = 0;
@@ -519,6 +523,49 @@ int _ltt_session_metadata_statedump(struct ltt_session *session)
                return -EPERM;
        }
 
+       snprintf(uuid_s, sizeof(uuid_s),
+               "%x%x%x%x-%x%x-%x%x-%x%x-%x%x%x%x%x%x",
+               uuid_s[0], uuid_s[1], uuid_s[2], uuid_s[3],
+               uuid_s[4], uuid_s[5], uuid_s[6], uuid_s[7],
+               uuid_s[8], uuid_s[9], uuid_s[10], uuid_s[11],
+               uuid_s[12], uuid_s[13], uuid_s[14], uuid_s[15]);
+
+       ret = lttng_metadata_printf(session,
+               "typealias integer {size = 8; align = %u; signed = false; } := uint8_t;\n"
+               "typealias integer {size = 32; align = %u; signed = false; } := uint32_t;\n"
+               "typealias integer {size = 64; align = %u; signed = false; } := uint64_t;\n"
+               "\n"
+               "trace {\n"
+               "       major = %u;\n"
+               "       minor = %u;\n"
+               "       uuid = %s;\n"
+               "       byte_order = %s;\n"
+               "       packet.header := struct {\n"
+               "               uint32_t magic;\n"
+               "               uint8_t  trace_uuid[16];\n"
+               "               uint32_t stream_id;\n"
+               "               uint64_t timestamp_begin;\n"
+               "               uint64_t timestamp_end;\n"
+               "               uint32_t content_size;\n"
+               "               uint32_t packet_size;\n"
+               "               uint32_t events_lost;\n"
+               "       };\n",
+               "};\n\n",
+               ltt_alignof(uint8_t) * CHAR_BIT,
+               ltt_alignof(uint32_t) * CHAR_BIT,
+               ltt_alignof(uint64_t) * CHAR_BIT,
+               CTF_VERSION_MAJOR,
+               CTF_VERSION_MINOR,
+               uuid_s,
+#ifdef __BIG_ENDIAN
+               "be"
+#else
+               "le"
+#endif
+               );
+       if (ret)
+               goto end;
+
 skip_session:
        list_for_each_entry(chan, &session->chan, list) {
                ret = _ltt_channel_metadata_statedump(session, chan);
index 3bacac785a2acd007f0a8c3bf5c06471100d7165..5b5dcb50ba14db062314dcfdb67d2aed85d0384e 100644 (file)
@@ -10,6 +10,7 @@
  */
 
 #include <linux/list.h>
+#include <linux/uuid.h>
 #include "ltt-debugfs-abi.h"
 
 struct ltt_channel;
@@ -46,7 +47,7 @@ struct lttng_enum_entry {
            .u.basic.integer =                                  \
                {                                               \
                  .size = sizeof(_type),                        \
-                 .alignment = __alignof__(_type),              \
+                 .alignment = ltt_alignof(_type) * CHAR_BIT,   \
                  .signedness = is_signed_type(_type),          \
                  .reverse_byte_order = _byte_order != __BYTE_ORDER,    \
                },                                              \
@@ -171,6 +172,7 @@ struct ltt_session {
        struct list_head events;        /* Event list head */
        struct list_head list;          /* Session list */
        unsigned int free_chan_id;      /* Next chan ID to allocate */
+       uuid_le uuid;                   /* Trace session unique ID */
        int metadata_dumped:1;
 };
 
index 9056dd79ba2e17ded7f3c47b50c06200cc1e319f..aa763837a974271d9df6932f23771a82bc8e840d 100644 (file)
 #include "ltt-events.h"
 #include "ltt-tracer.h"
 
+/*
+ * 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)
+                                        */
+#if 0
+       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 */
+};
+
+
 static inline notrace u64 lib_ring_buffer_clock_read(struct channel *chan)
 {
        return trace_clock_read64();
@@ -122,29 +157,6 @@ slow_path:
        ltt_write_event_header_slow(config, ctx, eID, event_size);
 }
 
-/**
- * ltt_write_trace_header - Write trace header
- * @priv: Private data (struct trace)
- * @header: Memory address where the information must be written to
- */
-static __inline__
-void write_trace_header(const struct lib_ring_buffer_config *config,
-                       struct packet_header *header)
-{
-       header->magic = CTF_MAGIC_NUMBER;
-#if 0
-       /* TODO: move start time to metadata */
-       header->major_version = LTT_TRACER_VERSION_MAJOR;
-       header->minor_version = LTT_TRACER_VERSION_MINOR;
-       header->arch_size = sizeof(void *);
-       header->alignment = lib_ring_buffer_get_alignment(config);
-       header->start_time_sec = ltt_chan->session->start_time.tv_sec;
-       header->start_time_usec = ltt_chan->session->start_time.tv_usec;
-       header->start_freq = ltt_chan->session->start_freq;
-       header->freq_scale = ltt_chan->session->freq_scale;
-#endif //0
-}
-
 void ltt_write_event_header_slow(const struct lib_ring_buffer_config *config,
                                   struct lib_ring_buffer_ctx *ctx,
                                   u16 eID, u32 event_size)
@@ -234,10 +246,21 @@ static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc,
                (struct packet_header *)
                        lib_ring_buffer_offset_address(&buf->backend,
                                subbuf_idx * chan->backend.subbuf_size);
+       struct ltt_session *session = channel_get_private(chan);
 
+       header->magic = CTF_MAGIC_NUMBER;
+       memcpy(header->trace_uuid, session->uuid.b, sizeof(session->uuid));
        header->timestamp_begin = tsc;
+       header->timestamp_end = 0;
        header->content_size = 0xFFFFFFFF; /* for debugging */
-       write_trace_header(&client_config, header);
+       header->packet_size = 0xFFFFFFFF;
+       header->events_lost = 0;
+#if 0
+       header->start_time_sec = ltt_chan->session->start_time.tv_sec;
+       header->start_time_usec = ltt_chan->session->start_time.tv_usec;
+       header->start_freq = ltt_chan->session->start_freq;
+       header->freq_scale = ltt_chan->session->freq_scale;
+#endif //0
 }
 
 /*
@@ -254,9 +277,9 @@ static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc,
                                subbuf_idx * chan->backend.subbuf_size);
        unsigned long records_lost = 0;
 
+       header->timestamp_end = tsc;
        header->content_size = data_size;
        header->packet_size = PAGE_ALIGN(data_size);
-       header->timestamp_end = tsc;
        records_lost += lib_ring_buffer_get_records_lost_full(&client_config, buf);
        records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf);
        records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf);
index a0f6f9e12f2c45c75e6d13db2b9cc0db5dc4cf2f..c6dce5f9703f3997729487971e9fc646d113d3d4 100644 (file)
@@ -86,10 +86,10 @@ static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc,
                (struct metadata_packet_header *)
                        lib_ring_buffer_offset_address(&buf->backend,
                                subbuf_idx * chan->backend.subbuf_size);
+       struct ltt_session *session = channel_get_private(chan);
 
        header->magic = TSDL_MAGIC_NUMBER;
-       /* TODO */
-       //header->trace_uuid = ;        /* Unique Universal Identifier */
+       memcpy(header->trace_uuid, session->uuid.b, sizeof(session->uuid));
        header->checksum = 0;           /* 0 if unused */
        header->content_size = 0xFFFFFFFF; /* in bits, for debugging */
        header->packet_size = 0xFFFFFFFF;  /* in bits, for debugging */
@@ -106,7 +106,7 @@ static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc,
                              unsigned int subbuf_idx, unsigned long data_size)
 {
        struct channel *chan = buf->backend.chan;
-       struct packet_header *header =
+       struct metadata_packet_header *header =
                (struct packet_header *)
                        lib_ring_buffer_offset_address(&buf->backend,
                                subbuf_idx * chan->backend.subbuf_size);
index 3bb55234aa5bea4bb2ff704a117fa06754c7668b..f1cd2d90f75e4d258f335c400a6c0aa759c9533c 100644 (file)
@@ -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
index f64e0217c3ee5fe2a7d5c3e72ef5d70bdb8070c1..5ee61bc612472bb49e5e8b12915da50a319e96b1 100644 (file)
@@ -222,7 +222,7 @@ static struct lttng_probe_desc TP_ID(__probe_desc___, TRACE_SYSTEM) = {
 
 #undef __field
 #define __field(_type, _item)                                                 \
-       __event_len += lib_ring_buffer_align(__event_len, __alignof__(_type)); \
+       __event_len += lib_ring_buffer_align(__event_len, ltt_alignof(_type)); \
        __event_len += sizeof(_type);
 
 #undef __field_ext
@@ -230,14 +230,14 @@ static struct lttng_probe_desc TP_ID(__probe_desc___, TRACE_SYSTEM) = {
 
 #undef __array
 #define __array(_type, _item, _length)                                        \
-       __event_len += lib_ring_buffer_align(__event_len, __alignof__(_type)); \
+       __event_len += lib_ring_buffer_align(__event_len, ltt_alignof(_type)); \
        __event_len += sizeof(_type) * (_length);
 
 #undef __dynamic_array
 #define __dynamic_array(_type, _item, _length)                                \
-       __event_len += lib_ring_buffer_align(__event_len, __alignof__(u32));   \
+       __event_len += lib_ring_buffer_align(__event_len, ltt_alignof(u32));   \
        __event_len += sizeof(u32);                                            \
-       __event_len += lib_ring_buffer_align(__event_len, __alignof__(_type)); \
+       __event_len += lib_ring_buffer_align(__event_len, ltt_alignof(_type)); \
        __event_len += sizeof(_type) * (_length);
 
 #undef __string
@@ -277,19 +277,19 @@ static inline size_t __event_get_size__##_name(size_t *__dynamic_len, _proto) \
 
 #undef __field
 #define __field(_type, _item)                                            \
-       __event_align = max_t(size_t, __event_align, __alignof__(_type));
+       __event_align = max_t(size_t, __event_align, ltt_alignof(_type));
 
 #undef __field_ext
 #define __field_ext(_type, _item, _filter_type)        __field(_type, _item)
 
 #undef __array
 #define __array(_type, _item, _length)                                   \
-       __event_align = max_t(size_t, __event_align, __alignof__(_type));
+       __event_align = max_t(size_t, __event_align, ltt_alignof(_type));
 
 #undef __dynamic_array
 #define __dynamic_array(_type, _item, _length)                           \
-       __event_align = max_t(size_t, __event_align, __alignof__(u32));   \
-       __event_align = max_t(size_t, __event_align, __alignof__(_type));
+       __event_align = max_t(size_t, __event_align, ltt_alignof(u32));   \
+       __event_align = max_t(size_t, __event_align, ltt_alignof(_type));
 
 #undef __string
 #define __string(_item, _src)
@@ -397,7 +397,7 @@ __end_field_##_item:
 __assign_##dest:                                                       \
        {                                                               \
                __typeof__(__typemap.dest) __tmp = (src);               \
-               lib_ring_buffer_align_ctx(&ctx, __alignof__(__tmp));    \
+               lib_ring_buffer_align_ctx(&ctx, ltt_alignof(__tmp));    \
                __chan->ops->event_write(&ctx, &__tmp, sizeof(__tmp));  \
        }                                                               \
        goto __end_field_##dest;
@@ -405,7 +405,9 @@ __assign_##dest:                                                    \
 #undef tp_memcpy
 #define tp_memcpy(dest, src, len)                                      \
 __assign_##dest:                                                       \
-       lib_ring_buffer_align_ctx(&ctx, __alignof__(__typemap.dest));   \
+       if (0)                                                          \
+               (void) __typemap.dest;                                  \
+       lib_ring_buffer_align_ctx(&ctx, ltt_alignof(__typemap.dest));   \
        __chan->ops->event_write(&ctx, src, len);                       \
        goto __end_field_##dest;
 
@@ -414,12 +416,12 @@ __assign_##dest:                                                  \
 __assign_##dest##_1:                                                   \
        {                                                               \
                u32 __tmpl = (len);                                     \
-               lib_ring_buffer_align_ctx(&ctx, __alignof__(u32));      \
+               lib_ring_buffer_align_ctx(&ctx, ltt_alignof(u32));      \
                __chan->ops->event_write(&ctx, &__tmpl, sizeof(u32));   \
        }                                                               \
        goto __end_field_##dest##_1;                                    \
 __assign_##dest##_2:                                                   \
-       lib_ring_buffer_align_ctx(&ctx, __alignof__(__typemap.dest));   \
+       lib_ring_buffer_align_ctx(&ctx, ltt_alignof(__typemap.dest));   \
        __chan->ops->event_write(&ctx, src, len);                       \
        goto __end_field_##dest##_2;
 
index bbae874742e56a19a11a1050c276b1049e849644..5a7a655445bdf1561b24586399c9d44f02fd78fc 100644 (file)
@@ -8,6 +8,7 @@
 #include <linux/seq_file.h>
 #include "lttng.h"
 #include "../ltt-events.h"
+#include "../ltt-tracer.h"
 
 #ifdef __KERNEL__
 # include <asm/byteorder.h>
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