lttng: lib ring buffer clients
authorMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Mon, 28 Nov 2011 12:42:17 +0000 (07:42 -0500)
committerGreg Kroah-Hartman <gregkh@suse.de>
Tue, 29 Nov 2011 01:05:06 +0000 (10:05 +0900)
Each lttng buffer configuration (discard mode, overwrite mode, mmap
support, splice support, per-cpu buffers, global buffer for metadata) is
a lib ring buffer client.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/staging/lttng/ltt-ring-buffer-client-discard.c [new file with mode: 0644]
drivers/staging/lttng/ltt-ring-buffer-client-mmap-discard.c [new file with mode: 0644]
drivers/staging/lttng/ltt-ring-buffer-client-mmap-overwrite.c [new file with mode: 0644]
drivers/staging/lttng/ltt-ring-buffer-client-overwrite.c [new file with mode: 0644]
drivers/staging/lttng/ltt-ring-buffer-client.h [new file with mode: 0644]
drivers/staging/lttng/ltt-ring-buffer-metadata-client.c [new file with mode: 0644]
drivers/staging/lttng/ltt-ring-buffer-metadata-client.h [new file with mode: 0644]
drivers/staging/lttng/ltt-ring-buffer-metadata-mmap-client.c [new file with mode: 0644]

diff --git a/drivers/staging/lttng/ltt-ring-buffer-client-discard.c b/drivers/staging/lttng/ltt-ring-buffer-client-discard.c
new file mode 100644 (file)
index 0000000..eafcf45
--- /dev/null
@@ -0,0 +1,21 @@
+/*
+ * ltt-ring-buffer-client-discard.c
+ *
+ * Copyright (C) 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * LTTng lib ring buffer client (discard mode).
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#include <linux/module.h>
+#include "ltt-tracer.h"
+
+#define RING_BUFFER_MODE_TEMPLATE              RING_BUFFER_DISCARD
+#define RING_BUFFER_MODE_TEMPLATE_STRING       "discard"
+#define RING_BUFFER_OUTPUT_TEMPLATE            RING_BUFFER_SPLICE
+#include "ltt-ring-buffer-client.h"
+
+MODULE_LICENSE("GPL and additional rights");
+MODULE_AUTHOR("Mathieu Desnoyers");
+MODULE_DESCRIPTION("LTTng Ring Buffer Client Discard Mode");
diff --git a/drivers/staging/lttng/ltt-ring-buffer-client-mmap-discard.c b/drivers/staging/lttng/ltt-ring-buffer-client-mmap-discard.c
new file mode 100644 (file)
index 0000000..29819a7
--- /dev/null
@@ -0,0 +1,21 @@
+/*
+ * ltt-ring-buffer-client-discard.c
+ *
+ * Copyright (C) 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * LTTng lib ring buffer client (discard mode).
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#include <linux/module.h>
+#include "ltt-tracer.h"
+
+#define RING_BUFFER_MODE_TEMPLATE              RING_BUFFER_DISCARD
+#define RING_BUFFER_MODE_TEMPLATE_STRING       "discard-mmap"
+#define RING_BUFFER_OUTPUT_TEMPLATE            RING_BUFFER_MMAP
+#include "ltt-ring-buffer-client.h"
+
+MODULE_LICENSE("GPL and additional rights");
+MODULE_AUTHOR("Mathieu Desnoyers");
+MODULE_DESCRIPTION("LTTng Ring Buffer Client Discard Mode");
diff --git a/drivers/staging/lttng/ltt-ring-buffer-client-mmap-overwrite.c b/drivers/staging/lttng/ltt-ring-buffer-client-mmap-overwrite.c
new file mode 100644 (file)
index 0000000..741aa7b
--- /dev/null
@@ -0,0 +1,21 @@
+/*
+ * ltt-ring-buffer-client-overwrite.c
+ *
+ * Copyright (C) 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * LTTng lib ring buffer client (overwrite mode).
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#include <linux/module.h>
+#include "ltt-tracer.h"
+
+#define RING_BUFFER_MODE_TEMPLATE              RING_BUFFER_OVERWRITE
+#define RING_BUFFER_MODE_TEMPLATE_STRING       "overwrite-mmap"
+#define RING_BUFFER_OUTPUT_TEMPLATE            RING_BUFFER_MMAP
+#include "ltt-ring-buffer-client.h"
+
+MODULE_LICENSE("GPL and additional rights");
+MODULE_AUTHOR("Mathieu Desnoyers");
+MODULE_DESCRIPTION("LTTng Ring Buffer Client Overwrite Mode");
diff --git a/drivers/staging/lttng/ltt-ring-buffer-client-overwrite.c b/drivers/staging/lttng/ltt-ring-buffer-client-overwrite.c
new file mode 100644 (file)
index 0000000..9811941
--- /dev/null
@@ -0,0 +1,21 @@
+/*
+ * ltt-ring-buffer-client-overwrite.c
+ *
+ * Copyright (C) 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * LTTng lib ring buffer client (overwrite mode).
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#include <linux/module.h>
+#include "ltt-tracer.h"
+
+#define RING_BUFFER_MODE_TEMPLATE              RING_BUFFER_OVERWRITE
+#define RING_BUFFER_MODE_TEMPLATE_STRING       "overwrite"
+#define RING_BUFFER_OUTPUT_TEMPLATE            RING_BUFFER_SPLICE
+#include "ltt-ring-buffer-client.h"
+
+MODULE_LICENSE("GPL and additional rights");
+MODULE_AUTHOR("Mathieu Desnoyers");
+MODULE_DESCRIPTION("LTTng Ring Buffer Client Overwrite Mode");
diff --git a/drivers/staging/lttng/ltt-ring-buffer-client.h b/drivers/staging/lttng/ltt-ring-buffer-client.h
new file mode 100644 (file)
index 0000000..8df3790
--- /dev/null
@@ -0,0 +1,569 @@
+/*
+ * ltt-ring-buffer-client.h
+ *
+ * Copyright (C) 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * LTTng lib ring buffer client template.
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#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.
+ *
+ * The guarantee we have with timestamps is that all the events in a
+ * packet are included (inclusive) within the begin/end timestamps of
+ * the packet. Another guarantee we have is that the "timestamp begin",
+ * as well as the event timestamps, are monotonically increasing (never
+ * decrease) when moving forward in a stream (physically). But this
+ * guarantee does not apply to "timestamp end", because it is sampled at
+ * commit time, which is not ordered with respect to space reservation.
+ */
+
+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:
+               padding = 0;
+               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"
+
+static
+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, ltt_chan->ctx);
+       ctx_record(ctx, ltt_chan, event->ctx);
+       lib_ring_buffer_align_ctx(ctx, ctx->largest_align);
+
+       return;
+
+slow_path:
+       ltt_write_event_header_slow(config, ctx, event_id);
+}
+
+static
+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, ltt_chan->ctx);
+       ctx_record(ctx, ltt_chan, event->ctx);
+       lib_ring_buffer_align_ctx(ctx, ctx->largest_align);
+}
+
+static const struct lib_ring_buffer_config client_config;
+
+static u64 client_ring_buffer_clock_read(struct channel *chan)
+{
+       return lib_ring_buffer_clock_read(chan);
+}
+
+static
+size_t client_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)
+{
+       return record_header_size(config, chan, offset,
+                                 pre_header_padding, ctx);
+}
+
+/**
+ * client_packet_header_size - called on buffer-switch to a new sub-buffer
+ *
+ * Return header size without padding after the structure. Don't use packed
+ * structure because gcc generates inefficient code on some architectures
+ * (powerpc, mips..)
+ */
+static size_t client_packet_header_size(void)
+{
+       return offsetof(struct packet_header, ctx.header_end);
+}
+
+static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc,
+                               unsigned int subbuf_idx)
+{
+       struct channel *chan = buf->backend.chan;
+       struct packet_header *header =
+               (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->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;
+}
+
+/*
+ * offset is assumed to never be 0 here : never deliver a completely empty
+ * subbuffer. data_size is between 1 and subbuf_size.
+ */
+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 packet_header *)
+                       lib_ring_buffer_offset_address(&buf->backend,
+                               subbuf_idx * chan->backend.subbuf_size);
+       unsigned long records_lost = 0;
+
+       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->ctx.events_discarded = records_lost;
+}
+
+static int client_buffer_create(struct lib_ring_buffer *buf, void *priv,
+                               int cpu, const char *name)
+{
+       return 0;
+}
+
+static void client_buffer_finalize(struct lib_ring_buffer *buf, void *priv, int cpu)
+{
+}
+
+static const struct lib_ring_buffer_config client_config = {
+       .cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
+       .cb.record_header_size = client_record_header_size,
+       .cb.subbuffer_header_size = client_packet_header_size,
+       .cb.buffer_begin = client_buffer_begin,
+       .cb.buffer_end = client_buffer_end,
+       .cb.buffer_create = client_buffer_create,
+       .cb.buffer_finalize = client_buffer_finalize,
+
+       .tsc_bits = 32,
+       .alloc = RING_BUFFER_ALLOC_PER_CPU,
+       .sync = RING_BUFFER_SYNC_PER_CPU,
+       .mode = RING_BUFFER_MODE_TEMPLATE,
+       .backend = RING_BUFFER_PAGE,
+       .output = RING_BUFFER_OUTPUT_TEMPLATE,
+       .oops = RING_BUFFER_OOPS_CONSISTENCY,
+       .ipi = RING_BUFFER_IPI_BARRIER,
+       .wakeup = RING_BUFFER_WAKEUP_BY_TIMER,
+};
+
+static
+struct channel *_channel_create(const char *name,
+                               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, ltt_chan, buf_addr,
+                             subbuf_size, num_subbuf, switch_timer_interval,
+                             read_timer_interval);
+}
+
+static
+void ltt_channel_destroy(struct channel *chan)
+{
+       channel_destroy(chan);
+}
+
+static
+struct lib_ring_buffer *ltt_buffer_read_open(struct channel *chan)
+{
+       struct lib_ring_buffer *buf;
+       int cpu;
+
+       for_each_channel_cpu(cpu, chan) {
+               buf = channel_get_ring_buffer(&client_config, chan, cpu);
+               if (!lib_ring_buffer_open_read(buf))
+                       return buf;
+       }
+       return NULL;
+}
+
+static
+int ltt_buffer_has_read_closed_stream(struct channel *chan)
+{
+       struct lib_ring_buffer *buf;
+       int cpu;
+
+       for_each_channel_cpu(cpu, chan) {
+               buf = channel_get_ring_buffer(&client_config, chan, cpu);
+               if (!atomic_long_read(&buf->active_readers))
+                       return 1;
+       }
+       return 0;
+}
+
+static
+void ltt_buffer_read_close(struct lib_ring_buffer *buf)
+{
+       lib_ring_buffer_release_read(buf);
+}
+
+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);
+       if (cpu < 0)
+               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;
+       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
+void ltt_event_write_from_user(struct lib_ring_buffer_ctx *ctx,
+                              const void __user *src, size_t len)
+{
+       lib_ring_buffer_copy_from_user(&client_config, ctx, src, len);
+}
+
+static
+void ltt_event_memset(struct lib_ring_buffer_ctx *ctx,
+               int c, size_t len)
+{
+       lib_ring_buffer_memset(&client_config, ctx, c, len);
+}
+
+static
+wait_queue_head_t *ltt_get_writer_buf_wait_queue(struct channel *chan, int cpu)
+{
+       struct lib_ring_buffer *buf = channel_get_ring_buffer(&client_config,
+                                       chan, cpu);
+       return &buf->write_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,
+       .ops = {
+               .channel_create = _channel_create,
+               .channel_destroy = ltt_channel_destroy,
+               .buffer_read_open = ltt_buffer_read_open,
+               .buffer_has_read_closed_stream =
+                       ltt_buffer_has_read_closed_stream,
+               .buffer_read_close = ltt_buffer_read_close,
+               .event_reserve = ltt_event_reserve,
+               .event_commit = ltt_event_commit,
+               .event_write = ltt_event_write,
+               .event_write_from_user = ltt_event_write_from_user,
+               .event_memset = ltt_event_memset,
+               .packet_avail_size = NULL,      /* Would be racy anyway */
+               .get_writer_buf_wait_queue = ltt_get_writer_buf_wait_queue,
+               .get_hp_wait_queue = ltt_get_hp_wait_queue,
+               .is_finalized = ltt_is_finalized,
+               .is_disabled = ltt_is_disabled,
+       },
+};
+
+static int __init ltt_ring_buffer_client_init(void)
+{
+       /*
+        * This vmalloc sync all also takes care of the lib ring buffer
+        * vmalloc'd module pages when it is built as a module into LTTng.
+        */
+       wrapper_vmalloc_sync_all();
+       ltt_transport_register(&ltt_relay_transport);
+       return 0;
+}
+
+module_init(ltt_ring_buffer_client_init);
+
+static void __exit ltt_ring_buffer_client_exit(void)
+{
+       ltt_transport_unregister(&ltt_relay_transport);
+}
+
+module_exit(ltt_ring_buffer_client_exit);
+
+MODULE_LICENSE("GPL and additional rights");
+MODULE_AUTHOR("Mathieu Desnoyers");
+MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING
+                  " client");
diff --git a/drivers/staging/lttng/ltt-ring-buffer-metadata-client.c b/drivers/staging/lttng/ltt-ring-buffer-metadata-client.c
new file mode 100644 (file)
index 0000000..ac6fe78
--- /dev/null
@@ -0,0 +1,21 @@
+/*
+ * ltt-ring-buffer-metadata-client.c
+ *
+ * Copyright (C) 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * LTTng lib ring buffer metadta client.
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#include <linux/module.h>
+#include "ltt-tracer.h"
+
+#define RING_BUFFER_MODE_TEMPLATE              RING_BUFFER_DISCARD
+#define RING_BUFFER_MODE_TEMPLATE_STRING       "metadata"
+#define RING_BUFFER_OUTPUT_TEMPLATE            RING_BUFFER_SPLICE
+#include "ltt-ring-buffer-metadata-client.h"
+
+MODULE_LICENSE("GPL and additional rights");
+MODULE_AUTHOR("Mathieu Desnoyers");
+MODULE_DESCRIPTION("LTTng Ring Buffer Metadata Client");
diff --git a/drivers/staging/lttng/ltt-ring-buffer-metadata-client.h b/drivers/staging/lttng/ltt-ring-buffer-metadata-client.h
new file mode 100644 (file)
index 0000000..529bbb1
--- /dev/null
@@ -0,0 +1,330 @@
+/*
+ * ltt-ring-buffer-client.h
+ *
+ * Copyright (C) 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * LTTng lib ring buffer client template.
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include "wrapper/vmalloc.h"   /* for wrapper_vmalloc_sync_all() */
+#include "ltt-events.h"
+#include "ltt-tracer.h"
+
+struct metadata_packet_header {
+       uint32_t magic;                 /* 0x75D11D57 */
+       uint8_t  uuid[16];              /* Unique Universal Identifier */
+       uint32_t checksum;              /* 0 if unused */
+       uint32_t content_size;          /* in bits */
+       uint32_t packet_size;           /* in bits */
+       uint8_t  compression_scheme;    /* 0 if unused */
+       uint8_t  encryption_scheme;     /* 0 if unused */
+       uint8_t  checksum_scheme;       /* 0 if unused */
+       uint8_t  major;                 /* CTF spec major version number */
+       uint8_t  minor;                 /* CTF spec minor version number */
+       uint8_t  header_end[0];
+};
+
+struct metadata_record_header {
+       uint8_t header_end[0];          /* End of header */
+};
+
+static const struct lib_ring_buffer_config client_config;
+
+static inline
+u64 lib_ring_buffer_clock_read(struct channel *chan)
+{
+       return 0;
+}
+
+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)
+{
+       return 0;
+}
+
+#include "wrapper/ringbuffer/api.h"
+
+static u64 client_ring_buffer_clock_read(struct channel *chan)
+{
+       return 0;
+}
+
+static
+size_t client_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)
+{
+       return 0;
+}
+
+/**
+ * client_packet_header_size - called on buffer-switch to a new sub-buffer
+ *
+ * Return header size without padding after the structure. Don't use packed
+ * structure because gcc generates inefficient code on some architectures
+ * (powerpc, mips..)
+ */
+static size_t client_packet_header_size(void)
+{
+       return offsetof(struct metadata_packet_header, header_end);
+}
+
+static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc,
+                               unsigned int subbuf_idx)
+{
+       struct channel *chan = buf->backend.chan;
+       struct metadata_packet_header *header =
+               (struct metadata_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->magic = TSDL_MAGIC_NUMBER;
+       memcpy(header->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 */
+       header->compression_scheme = 0; /* 0 if unused */
+       header->encryption_scheme = 0;  /* 0 if unused */
+       header->checksum_scheme = 0;    /* 0 if unused */
+       header->major = CTF_SPEC_MAJOR;
+       header->minor = CTF_SPEC_MINOR;
+}
+
+/*
+ * offset is assumed to never be 0 here : never deliver a completely empty
+ * subbuffer. data_size is between 1 and subbuf_size.
+ */
+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 metadata_packet_header *header =
+               (struct metadata_packet_header *)
+                       lib_ring_buffer_offset_address(&buf->backend,
+                               subbuf_idx * chan->backend.subbuf_size);
+       unsigned long records_lost = 0;
+
+       header->content_size = data_size * CHAR_BIT;            /* in bits */
+       header->packet_size = PAGE_ALIGN(data_size) * CHAR_BIT; /* in bits */
+       /*
+        * We do not care about the records lost count, because the metadata
+        * channel waits and retry.
+        */
+       (void) 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);
+       WARN_ON_ONCE(records_lost != 0);
+}
+
+static int client_buffer_create(struct lib_ring_buffer *buf, void *priv,
+                               int cpu, const char *name)
+{
+       return 0;
+}
+
+static void client_buffer_finalize(struct lib_ring_buffer *buf, void *priv, int cpu)
+{
+}
+
+static const struct lib_ring_buffer_config client_config = {
+       .cb.ring_buffer_clock_read = client_ring_buffer_clock_read,
+       .cb.record_header_size = client_record_header_size,
+       .cb.subbuffer_header_size = client_packet_header_size,
+       .cb.buffer_begin = client_buffer_begin,
+       .cb.buffer_end = client_buffer_end,
+       .cb.buffer_create = client_buffer_create,
+       .cb.buffer_finalize = client_buffer_finalize,
+
+       .tsc_bits = 0,
+       .alloc = RING_BUFFER_ALLOC_GLOBAL,
+       .sync = RING_BUFFER_SYNC_GLOBAL,
+       .mode = RING_BUFFER_MODE_TEMPLATE,
+       .backend = RING_BUFFER_PAGE,
+       .output = RING_BUFFER_OUTPUT_TEMPLATE,
+       .oops = RING_BUFFER_OOPS_CONSISTENCY,
+       .ipi = RING_BUFFER_IPI_BARRIER,
+       .wakeup = RING_BUFFER_WAKEUP_BY_TIMER,
+};
+
+static
+struct channel *_channel_create(const char *name,
+                               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, ltt_chan, buf_addr,
+                             subbuf_size, num_subbuf, switch_timer_interval,
+                             read_timer_interval);
+}
+
+static
+void ltt_channel_destroy(struct channel *chan)
+{
+       channel_destroy(chan);
+}
+
+static
+struct lib_ring_buffer *ltt_buffer_read_open(struct channel *chan)
+{
+       struct lib_ring_buffer *buf;
+
+       buf = channel_get_ring_buffer(&client_config, chan, 0);
+       if (!lib_ring_buffer_open_read(buf))
+               return buf;
+       return NULL;
+}
+
+static
+int ltt_buffer_has_read_closed_stream(struct channel *chan)
+{
+       struct lib_ring_buffer *buf;
+       int cpu;
+
+       for_each_channel_cpu(cpu, chan) {
+               buf = channel_get_ring_buffer(&client_config, chan, cpu);
+               if (!atomic_long_read(&buf->active_readers))
+                       return 1;
+       }
+       return 0;
+}
+
+static
+void ltt_buffer_read_close(struct lib_ring_buffer *buf)
+{
+       lib_ring_buffer_release_read(buf);
+}
+
+static
+int ltt_event_reserve(struct lib_ring_buffer_ctx *ctx, uint32_t event_id)
+{
+       return lib_ring_buffer_reserve(&client_config, ctx);
+}
+
+static
+void ltt_event_commit(struct lib_ring_buffer_ctx *ctx)
+{
+       lib_ring_buffer_commit(&client_config, ctx);
+}
+
+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
+void ltt_event_write_from_user(struct lib_ring_buffer_ctx *ctx,
+                              const void __user *src, size_t len)
+{
+       lib_ring_buffer_copy_from_user(&client_config, ctx, src, len);
+}
+
+static
+void ltt_event_memset(struct lib_ring_buffer_ctx *ctx,
+               int c, size_t len)
+{
+       lib_ring_buffer_memset(&client_config, ctx, c, len);
+}
+
+static
+size_t ltt_packet_avail_size(struct channel *chan)
+                            
+{
+       unsigned long o_begin;
+       struct lib_ring_buffer *buf;
+
+       buf = chan->backend.buf;        /* Only for global buffer ! */
+       o_begin = v_read(&client_config, &buf->offset);
+       if (subbuf_offset(o_begin, chan) != 0) {
+               return chan->backend.subbuf_size - subbuf_offset(o_begin, chan);
+       } else {
+               return chan->backend.subbuf_size - subbuf_offset(o_begin, chan)
+                       - sizeof(struct metadata_packet_header);
+       }
+}
+
+static
+wait_queue_head_t *ltt_get_writer_buf_wait_queue(struct channel *chan, int cpu)
+{
+       struct lib_ring_buffer *buf = channel_get_ring_buffer(&client_config,
+                                       chan, cpu);
+       return &buf->write_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,
+       .ops = {
+               .channel_create = _channel_create,
+               .channel_destroy = ltt_channel_destroy,
+               .buffer_read_open = ltt_buffer_read_open,
+               .buffer_has_read_closed_stream =
+                       ltt_buffer_has_read_closed_stream,
+               .buffer_read_close = ltt_buffer_read_close,
+               .event_reserve = ltt_event_reserve,
+               .event_commit = ltt_event_commit,
+               .event_write_from_user = ltt_event_write_from_user,
+               .event_memset = ltt_event_memset,
+               .event_write = ltt_event_write,
+               .packet_avail_size = ltt_packet_avail_size,
+               .get_writer_buf_wait_queue = ltt_get_writer_buf_wait_queue,
+               .get_hp_wait_queue = ltt_get_hp_wait_queue,
+               .is_finalized = ltt_is_finalized,
+               .is_disabled = ltt_is_disabled,
+       },
+};
+
+static int __init ltt_ring_buffer_client_init(void)
+{
+       /*
+        * This vmalloc sync all also takes care of the lib ring buffer
+        * vmalloc'd module pages when it is built as a module into LTTng.
+        */
+       wrapper_vmalloc_sync_all();
+       ltt_transport_register(&ltt_relay_transport);
+       return 0;
+}
+
+module_init(ltt_ring_buffer_client_init);
+
+static void __exit ltt_ring_buffer_client_exit(void)
+{
+       ltt_transport_unregister(&ltt_relay_transport);
+}
+
+module_exit(ltt_ring_buffer_client_exit);
+
+MODULE_LICENSE("GPL and additional rights");
+MODULE_AUTHOR("Mathieu Desnoyers");
+MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING
+                  " client");
diff --git a/drivers/staging/lttng/ltt-ring-buffer-metadata-mmap-client.c b/drivers/staging/lttng/ltt-ring-buffer-metadata-mmap-client.c
new file mode 100644 (file)
index 0000000..5cad3f9
--- /dev/null
@@ -0,0 +1,21 @@
+/*
+ * ltt-ring-buffer-metadata-client.c
+ *
+ * Copyright (C) 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * LTTng lib ring buffer metadta client.
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#include <linux/module.h>
+#include "ltt-tracer.h"
+
+#define RING_BUFFER_MODE_TEMPLATE              RING_BUFFER_DISCARD
+#define RING_BUFFER_MODE_TEMPLATE_STRING       "metadata-mmap"
+#define RING_BUFFER_OUTPUT_TEMPLATE            RING_BUFFER_MMAP
+#include "ltt-ring-buffer-metadata-client.h"
+
+MODULE_LICENSE("GPL and additional rights");
+MODULE_AUTHOR("Mathieu Desnoyers");
+MODULE_DESCRIPTION("LTTng Ring Buffer Metadata Client");