Add mmap client mode
[lttng-modules.git] / ltt-ring-buffer-client.h
index 00cac1608a341c980a89939e230d88d5f6461a89..39587dd0b15f2054454a57bda420cc78ec680a62 100644 (file)
 
 #include <linux/module.h>
 #include <linux/types.h>
-#include "wrapper/symbols.h"   /* for wrapper_vmalloc_sync_all() */
+#include "lib/bitfield.h"
+#include "wrapper/vmalloc.h"   /* for wrapper_vmalloc_sync_all() */
 #include "wrapper/trace-clock.h"
 #include "ltt-events.h"
 #include "ltt-tracer.h"
+#include "wrapper/ringbuffer/frontend_types.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 {
+       /* Trace packet header */
+       uint32_t magic;                 /*
+                                        * Trace magic number.
+                                        * contains endianness information.
+                                        */
+       uint8_t uuid[16];
+       uint32_t stream_id;
+
+       struct {
+               /* Stream packet context */
+               uint64_t timestamp_begin;       /* Cycle count at subbuffer start */
+               uint64_t timestamp_end;         /* Cycle count at subbuffer end */
+               uint32_t events_discarded;      /*
+                                                * Events lost in this subbuffer since
+                                                * the beginning of the trace.
+                                                * (may overflow)
+                                                */
+               uint32_t content_size;          /* Size of data in subbuffer */
+               uint32_t packet_size;           /* Subbuffer size (include padding) */
+               uint32_t cpu_id;                /* CPU id associated with stream */
+               uint8_t header_end;             /* End of header */
+       } ctx;
+};
+
+
+static inline notrace u64 lib_ring_buffer_clock_read(struct channel *chan)
+{
+       return trace_clock_read64();
+}
+
+static inline
+size_t ctx_get_size(size_t offset, struct lttng_ctx *ctx)
+{
+       int i;
+       size_t orig_offset = offset;
+
+       if (likely(!ctx))
+               return 0;
+       for (i = 0; i < ctx->nr_fields; i++)
+               offset += ctx->fields[i].get_size(offset);
+       return offset - orig_offset;
+}
+
+static inline
+void ctx_record(struct lib_ring_buffer_ctx *bufctx,
+               struct ltt_channel *chan,
+               struct lttng_ctx *ctx)
+{
+       int i;
+
+       if (likely(!ctx))
+               return;
+       for (i = 0; i < ctx->nr_fields; i++)
+               ctx->fields[i].record(&ctx->fields[i], bufctx, chan);
+}
+
+/*
+ * record_header_size - Calculate the header size and padding necessary.
+ * @config: ring buffer instance configuration
+ * @chan: channel
+ * @offset: offset in the write buffer
+ * @pre_header_padding: padding to add before the header (output)
+ * @ctx: reservation context
+ *
+ * Returns the event header size (including padding).
+ *
+ * The payload must itself determine its own alignment from the biggest type it
+ * contains.
+ */
+static __inline__
+unsigned char record_header_size(const struct lib_ring_buffer_config *config,
+                                struct channel *chan, size_t offset,
+                                size_t *pre_header_padding,
+                                struct lib_ring_buffer_ctx *ctx)
+{
+       struct ltt_channel *ltt_chan = channel_get_private(chan);
+       struct ltt_event *event = ctx->priv;
+       size_t orig_offset = offset;
+       size_t padding;
+
+       switch (ltt_chan->header_type) {
+       case 1: /* compact */
+               padding = lib_ring_buffer_align(offset, ltt_alignof(uint32_t));
+               offset += padding;
+               if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC | LTT_RFLAG_EXTENDED))) {
+                       offset += sizeof(uint32_t);     /* id and timestamp */
+               } else {
+                       /* Minimum space taken by 5-bit id */
+                       offset += sizeof(uint8_t);
+                       /* Align extended struct on largest member */
+                       offset += lib_ring_buffer_align(offset, ltt_alignof(uint64_t));
+                       offset += sizeof(uint32_t);     /* id */
+                       offset += lib_ring_buffer_align(offset, ltt_alignof(uint64_t));
+                       offset += sizeof(uint64_t);     /* timestamp */
+               }
+               break;
+       case 2: /* large */
+               padding = lib_ring_buffer_align(offset, ltt_alignof(uint16_t));
+               offset += padding;
+               offset += sizeof(uint16_t);
+               if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC | LTT_RFLAG_EXTENDED))) {
+                       offset += lib_ring_buffer_align(offset, ltt_alignof(uint32_t));
+                       offset += sizeof(uint32_t);     /* timestamp */
+               } else {
+                       /* Align extended struct on largest member */
+                       offset += lib_ring_buffer_align(offset, ltt_alignof(uint64_t));
+                       offset += sizeof(uint32_t);     /* id */
+                       offset += lib_ring_buffer_align(offset, ltt_alignof(uint64_t));
+                       offset += sizeof(uint64_t);     /* timestamp */
+               }
+               break;
+       default:
+               WARN_ON_ONCE(1);
+       }
+       offset += ctx_get_size(offset, event->ctx);
+       offset += ctx_get_size(offset, ltt_chan->ctx);
+
+       *pre_header_padding = padding;
+       return offset - orig_offset;
+}
+
+#include "wrapper/ringbuffer/api.h"
+
+extern
+void ltt_write_event_header_slow(const struct lib_ring_buffer_config *config,
+                                struct lib_ring_buffer_ctx *ctx,
+                                uint32_t event_id);
+
+/*
+ * ltt_write_event_header
+ *
+ * Writes the event header to the offset (already aligned on 32-bits).
+ *
+ * @config: ring buffer instance configuration
+ * @ctx: reservation context
+ * @event_id: event ID
+ */
+static __inline__
+void ltt_write_event_header(const struct lib_ring_buffer_config *config,
+                           struct lib_ring_buffer_ctx *ctx,
+                           uint32_t event_id)
+{
+       struct ltt_channel *ltt_chan = channel_get_private(ctx->chan);
+       struct ltt_event *event = ctx->priv;
+
+       if (unlikely(ctx->rflags))
+               goto slow_path;
+
+       switch (ltt_chan->header_type) {
+       case 1: /* compact */
+       {
+               uint32_t id_time = 0;
+
+               bt_bitfield_write(&id_time, uint32_t, 0, 5, event_id);
+               bt_bitfield_write(&id_time, uint32_t, 5, 27, ctx->tsc);
+               lib_ring_buffer_write(config, ctx, &id_time, sizeof(id_time));
+               break;
+       }
+       case 2: /* large */
+       {
+               uint32_t timestamp = (uint32_t) ctx->tsc;
+               uint16_t id = event_id;
+
+               lib_ring_buffer_write(config, ctx, &id, sizeof(id));
+               lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint32_t));
+               lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
+               break;
+       }
+       default:
+               WARN_ON_ONCE(1);
+       }
+
+       ctx_record(ctx, ltt_chan, event->ctx);
+       ctx_record(ctx, ltt_chan, ltt_chan->ctx);
+
+       return;
+
+slow_path:
+       ltt_write_event_header_slow(config, ctx, event_id);
+}
+
+void ltt_write_event_header_slow(const struct lib_ring_buffer_config *config,
+                                struct lib_ring_buffer_ctx *ctx,
+                                uint32_t event_id)
+{
+       struct ltt_channel *ltt_chan = channel_get_private(ctx->chan);
+       struct ltt_event *event = ctx->priv;
+
+       switch (ltt_chan->header_type) {
+       case 1: /* compact */
+               if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC | LTT_RFLAG_EXTENDED))) {
+                       uint32_t id_time = 0;
+
+                       bt_bitfield_write(&id_time, uint32_t, 0, 5, event_id);
+                       bt_bitfield_write(&id_time, uint32_t, 5, 27, ctx->tsc);
+                       lib_ring_buffer_write(config, ctx, &id_time, sizeof(id_time));
+               } else {
+                       uint8_t id = 0;
+                       uint64_t timestamp = ctx->tsc;
+
+                       bt_bitfield_write(&id, uint8_t, 0, 5, 31);
+                       lib_ring_buffer_write(config, ctx, &id, sizeof(id));
+                       /* Align extended struct on largest member */
+                       lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
+                       lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
+                       lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
+                       lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
+               }
+               break;
+       case 2: /* large */
+       {
+               if (!(ctx->rflags & (RING_BUFFER_RFLAG_FULL_TSC | LTT_RFLAG_EXTENDED))) {
+                       uint32_t timestamp = (uint32_t) ctx->tsc;
+                       uint16_t id = event_id;
+
+                       lib_ring_buffer_write(config, ctx, &id, sizeof(id));
+                       lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint32_t));
+                       lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
+               } else {
+                       uint16_t id = 65535;
+                       uint64_t timestamp = ctx->tsc;
+
+                       lib_ring_buffer_write(config, ctx, &id, sizeof(id));
+                       /* Align extended struct on largest member */
+                       lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
+                       lib_ring_buffer_write(config, ctx, &event_id, sizeof(event_id));
+                       lib_ring_buffer_align_ctx(ctx, ltt_alignof(uint64_t));
+                       lib_ring_buffer_write(config, ctx, &timestamp, sizeof(timestamp));
+               }
+               break;
+       }
+       default:
+               WARN_ON_ONCE(1);
+       }
+       ctx_record(ctx, ltt_chan, event->ctx);
+       ctx_record(ctx, ltt_chan, ltt_chan->ctx);
+}
 
 static const struct lib_ring_buffer_config client_config;
 
@@ -25,13 +273,11 @@ static u64 client_ring_buffer_clock_read(struct channel *chan)
 static
 size_t client_record_header_size(const struct lib_ring_buffer_config *config,
                                 struct channel *chan, size_t offset,
-                                size_t data_size,
                                 size_t *pre_header_padding,
-                                unsigned int rflags,
                                 struct lib_ring_buffer_ctx *ctx)
 {
-       return record_header_size(config, chan, offset, data_size,
-                                 pre_header_padding, rflags, ctx);
+       return record_header_size(config, chan, offset,
+                                 pre_header_padding, ctx);
 }
 
 /**
@@ -43,7 +289,7 @@ size_t client_record_header_size(const struct lib_ring_buffer_config *config,
  */
 static size_t client_packet_header_size(void)
 {
-       return offsetof(struct packet_header, header_end);
+       return offsetof(struct packet_header, ctx.header_end);
 }
 
 static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc,
@@ -54,10 +300,18 @@ 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_channel *ltt_chan = channel_get_private(chan);
+       struct ltt_session *session = ltt_chan->session;
 
-       header->timestamp_begin = tsc;
-       header->content_size = 0xFFFFFFFF; /* for debugging */
-       write_trace_header(&client_config, header);
+       header->magic = CTF_MAGIC_NUMBER;
+       memcpy(header->uuid, session->uuid.b, sizeof(session->uuid));
+       header->stream_id = ltt_chan->id;
+       header->ctx.timestamp_begin = tsc;
+       header->ctx.timestamp_end = 0;
+       header->ctx.events_discarded = 0;
+       header->ctx.content_size = 0xFFFFFFFF; /* for debugging */
+       header->ctx.packet_size = 0xFFFFFFFF;
+       header->ctx.cpu_id = buf->backend.cpu;
 }
 
 /*
@@ -74,13 +328,13 @@ static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc,
                                subbuf_idx * chan->backend.subbuf_size);
        unsigned long records_lost = 0;
 
-       header->content_size = data_size;
-       header->packet_size = PAGE_ALIGN(data_size);
-       header->timestamp_end = tsc;
+       header->ctx.timestamp_end = tsc;
+       header->ctx.content_size = data_size * CHAR_BIT;        /* in bits */
+       header->ctx.packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
        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);
-       header->events_lost = records_lost;
+       header->ctx.events_discarded = records_lost;
 }
 
 static int client_buffer_create(struct lib_ring_buffer *buf, void *priv,
@@ -107,7 +361,7 @@ static const struct lib_ring_buffer_config client_config = {
        .sync = RING_BUFFER_SYNC_PER_CPU,
        .mode = RING_BUFFER_MODE_TEMPLATE,
        .backend = RING_BUFFER_PAGE,
-       .output = RING_BUFFER_SPLICE,
+       .output = RING_BUFFER_OUTPUT_TEMPLATE,
        .oops = RING_BUFFER_OOPS_CONSISTENCY,
        .ipi = RING_BUFFER_IPI_BARRIER,
        .wakeup = RING_BUFFER_WAKEUP_BY_TIMER,
@@ -115,12 +369,12 @@ static const struct lib_ring_buffer_config client_config = {
 
 static
 struct channel *_channel_create(const char *name,
-                               struct ltt_session *session, void *buf_addr,
+                               struct ltt_channel *ltt_chan, void *buf_addr,
                                size_t subbuf_size, size_t num_subbuf,
                                unsigned int switch_timer_interval,
                                unsigned int read_timer_interval)
 {
-       return channel_create(&client_config, name, session, buf_addr,
+       return channel_create(&client_config, name, ltt_chan, buf_addr,
                              subbuf_size, num_subbuf, switch_timer_interval,
                              read_timer_interval);
 }
@@ -149,11 +403,13 @@ static
 void ltt_buffer_read_close(struct lib_ring_buffer *buf)
 {
        lib_ring_buffer_release_read(buf);
-       
 }
 
-int ltt_event_reserve(struct lib_ring_buffer_ctx *ctx)
+static
+int ltt_event_reserve(struct lib_ring_buffer_ctx *ctx,
+                     uint32_t event_id)
 {
+       struct ltt_channel *ltt_chan = channel_get_private(ctx->chan);
        int ret, cpu;
 
        cpu = lib_ring_buffer_get_cpu(&client_config);
@@ -161,28 +417,67 @@ int ltt_event_reserve(struct lib_ring_buffer_ctx *ctx)
                return -EPERM;
        ctx->cpu = cpu;
 
+       switch (ltt_chan->header_type) {
+       case 1: /* compact */
+               if (event_id > 30)
+                       ctx->rflags |= LTT_RFLAG_EXTENDED;
+               break;
+       case 2: /* large */
+               if (event_id > 65534)
+                       ctx->rflags |= LTT_RFLAG_EXTENDED;
+               break;
+       default:
+               WARN_ON_ONCE(1);
+       }
+
        ret = lib_ring_buffer_reserve(&client_config, ctx);
        if (ret)
                goto put;
-       return ret;
-
+       ltt_write_event_header(&client_config, ctx, event_id);
+       return 0;
 put:
        lib_ring_buffer_put_cpu(&client_config);
        return ret;
 }
 
+static
 void ltt_event_commit(struct lib_ring_buffer_ctx *ctx)
 {
        lib_ring_buffer_commit(&client_config, ctx);
        lib_ring_buffer_put_cpu(&client_config);
 }
 
+static
 void ltt_event_write(struct lib_ring_buffer_ctx *ctx, const void *src,
                     size_t len)
 {
        lib_ring_buffer_write(&client_config, ctx, src, len);
 }
 
+static
+wait_queue_head_t *ltt_get_reader_wait_queue(struct channel *chan)
+{
+       return &chan->read_wait;
+}
+
+static
+wait_queue_head_t *ltt_get_hp_wait_queue(struct channel *chan)
+{
+       return &chan->hp_wait;
+}
+
+static
+int ltt_is_finalized(struct channel *chan)
+{
+       return lib_ring_buffer_channel_is_finalized(chan);
+}
+
+static
+int ltt_is_disabled(struct channel *chan)
+{
+       return lib_ring_buffer_channel_is_disabled(chan);
+}
+
 static struct ltt_transport ltt_relay_transport = {
        .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING,
        .owner = THIS_MODULE,
@@ -194,6 +489,11 @@ static struct ltt_transport ltt_relay_transport = {
                .event_reserve = ltt_event_reserve,
                .event_commit = ltt_event_commit,
                .event_write = ltt_event_write,
+               .packet_avail_size = NULL,      /* Would be racy anyway */
+               .get_reader_wait_queue = ltt_get_reader_wait_queue,
+               .get_hp_wait_queue = ltt_get_hp_wait_queue,
+               .is_finalized = ltt_is_finalized,
+               .is_disabled = ltt_is_disabled,
        },
 };
 
@@ -204,7 +504,6 @@ static int __init ltt_ring_buffer_client_init(void)
         * vmalloc'd module pages when it is built as a module into LTTng.
         */
        wrapper_vmalloc_sync_all();
-       printk(KERN_INFO "LTT : ltt ring buffer client init\n");
        ltt_transport_register(&ltt_relay_transport);
        return 0;
 }
@@ -213,7 +512,6 @@ module_init(ltt_ring_buffer_client_init);
 
 static void __exit ltt_ring_buffer_client_exit(void)
 {
-       printk(KERN_INFO "LTT : ltt ring buffer client exit\n");
        ltt_transport_unregister(&ltt_relay_transport);
 }
 
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