Move add data stream to the data thread
[lttng-tools.git] / src / common / kernel-consumer / kernel-consumer.c
index 47463c6501eddb48c4963d99c15b3d3c510c035c..1d725c2318b74029feb878289cfdfde55fa082fd 100644 (file)
@@ -118,7 +118,8 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
                new_channel = consumer_allocate_channel(msg.u.channel.channel_key,
                                -1, -1,
                                msg.u.channel.mmap_len,
-                               msg.u.channel.max_sb_size);
+                               msg.u.channel.max_sb_size,
+                               msg.u.channel.nb_init_streams);
                if (new_channel == NULL) {
                        lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
                        goto end_nosignal;
@@ -140,6 +141,7 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
                int fd;
                struct consumer_relayd_sock_pair *relayd = NULL;
                struct lttng_consumer_stream *new_stream;
+               int alloc_ret = 0;
 
                /* block */
                if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
@@ -165,12 +167,35 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
                                msg.u.stream.uid,
                                msg.u.stream.gid,
                                msg.u.stream.net_index,
-                               msg.u.stream.metadata_flag);
+                               msg.u.stream.metadata_flag,
+                               &alloc_ret);
                if (new_stream == NULL) {
-                       lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
+                       switch (alloc_ret) {
+                       case -ENOMEM:
+                       case -EINVAL:
+                       default:
+                               lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
+                               break;
+                       case -ENOENT:
+                               /*
+                                * We could not find the channel. Can happen if cpu hotplug
+                                * happens while tearing down.
+                                */
+                               DBG3("Could not find channel");
+                               break;
+                       }
                        goto end_nosignal;
                }
 
+               /*
+                * The buffer flush is done on the session daemon side for the kernel
+                * so no need for the stream "hangup_flush_done" variable to be
+                * tracked. This is important for a kernel stream since we don't rely
+                * on the flush state of the stream to read data. It's not the case for
+                * user space tracing.
+                */
+               new_stream->hangup_flush_done = 0;
+
                /* The stream is not metadata. Get relayd reference if exists. */
                relayd = consumer_find_relayd(msg.u.stream.net_index);
                if (relayd != NULL) {
@@ -181,24 +206,45 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
                                        &new_stream->relayd_stream_id);
                        pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
                        if (ret < 0) {
+                               consumer_del_stream(new_stream, NULL);
                                goto end_nosignal;
                        }
                } else if (msg.u.stream.net_index != -1) {
                        ERR("Network sequence index %d unknown. Not adding stream.",
                                        msg.u.stream.net_index);
-                       free(new_stream);
+                       consumer_del_stream(new_stream, NULL);
                        goto end_nosignal;
                }
 
-               if (ctx->on_recv_stream != NULL) {
+               if (ctx->on_recv_stream) {
                        ret = ctx->on_recv_stream(new_stream);
-                       if (ret == 0) {
-                               consumer_add_stream(new_stream);
-                       } else if (ret < 0) {
+                       if (ret < 0) {
+                               consumer_del_stream(new_stream, NULL);
+                               goto end_nosignal;
+                       }
+               }
+
+               /* Send stream to the metadata thread */
+               if (new_stream->metadata_flag) {
+                       do {
+                               ret = write(ctx->consumer_metadata_pipe[1], &new_stream,
+                                               sizeof(new_stream));
+                       } while (ret < 0 && errno == EINTR);
+                       if (ret < 0) {
+                               PERROR("write metadata pipe");
+                               consumer_del_stream(new_stream, NULL);
                                goto end_nosignal;
                        }
                } else {
-                       consumer_add_stream(new_stream);
+                       do {
+                               ret = write(ctx->consumer_poll_pipe[1], &new_stream,
+                                               sizeof(new_stream));
+                       } while (ret < 0 && errno == EINTR);
+                       if (ret < 0) {
+                               PERROR("write data pipe");
+                               consumer_del_stream(new_stream, NULL);
+                               goto end_nosignal;
+                       }
                }
 
                DBG("Kernel consumer_add_stream (%d)", fd);
@@ -241,20 +287,6 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
                goto end_nosignal;
        }
 
-       /*
-        * Wake-up the other end by writing a null byte in the pipe (non-blocking).
-        * Important note: Because writing into the pipe is non-blocking (and
-        * therefore we allow dropping wakeup data, as long as there is wakeup data
-        * present in the pipe buffer to wake up the other end), the other end
-        * should perform the following sequence for waiting:
-        *
-        * 1) empty the pipe (reads).
-        * 2) perform update operation.
-        * 3) wait on the pipe (poll).
-        */
-       do {
-               ret = write(ctx->consumer_poll_pipe[1], "", 1);
-       } while (ret < 0 && errno == EINTR);
 end_nosignal:
        rcu_read_unlock();
 
@@ -271,7 +303,7 @@ end_nosignal:
 ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
                struct lttng_consumer_local_data *ctx)
 {
-       unsigned long len;
+       unsigned long len, subbuf_size, padding;
        int err;
        ssize_t ret = 0;
        int infd = stream->wait_fd;
@@ -280,6 +312,7 @@ ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
        /* Get the next subbuffer */
        err = kernctl_get_next_subbuf(infd);
        if (err != 0) {
+               ret = err;
                /*
                 * This is a debug message even for single-threaded consumer,
                 * because poll() have more relaxed criterions than get subbuf,
@@ -291,60 +324,92 @@ ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
                goto end;
        }
 
+       /* Get the full subbuffer size including padding */
+       err = kernctl_get_padded_subbuf_size(infd, &len);
+       if (err != 0) {
+               errno = -err;
+               perror("Getting sub-buffer len failed.");
+               ret = err;
+               goto end;
+       }
+
        switch (stream->output) {
-               case LTTNG_EVENT_SPLICE:
-                       /* read the whole subbuffer */
-                       err = kernctl_get_padded_subbuf_size(infd, &len);
-                       if (err != 0) {
-                               errno = -ret;
-                               perror("Getting sub-buffer len failed.");
-                               goto end;
-                       }
+       case LTTNG_EVENT_SPLICE:
 
-                       /* splice the subbuffer to the tracefile */
-                       ret = lttng_consumer_on_read_subbuffer_splice(ctx, stream, len);
-                       if (ret != len) {
-                               /*
-                                * display the error but continue processing to try
-                                * to release the subbuffer
-                                */
-                               ERR("Error splicing to tracefile (ret: %zd != len: %lu)",
-                                               ret, len);
-                       }
+               /*
+                * XXX: The lttng-modules splice "actor" does not handle copying
+                * partial pages hence only using the subbuffer size without the
+                * padding makes the splice fail.
+                */
+               subbuf_size = len;
+               padding = 0;
 
-                       break;
-               case LTTNG_EVENT_MMAP:
-                       /* read the used subbuffer size */
-                       err = kernctl_get_padded_subbuf_size(infd, &len);
-                       if (err != 0) {
-                               errno = -ret;
-                               perror("Getting sub-buffer len failed.");
-                               goto end;
-                       }
-                       /* write the subbuffer to the tracefile */
-                       ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len);
-                       if (ret != len) {
-                               /*
-                                * display the error but continue processing to try
-                                * to release the subbuffer
-                                */
-                               ERR("Error writing to tracefile");
-                       }
-                       break;
-               default:
-                       ERR("Unknown output method");
-                       ret = -1;
+               /* splice the subbuffer to the tracefile */
+               ret = lttng_consumer_on_read_subbuffer_splice(ctx, stream, subbuf_size,
+                               padding);
+               /*
+                * XXX: Splice does not support network streaming so the return value
+                * is simply checked against subbuf_size and not like the mmap() op.
+                */
+               if (ret != subbuf_size) {
+                       /*
+                        * display the error but continue processing to try
+                        * to release the subbuffer
+                        */
+                       ERR("Error splicing to tracefile (ret: %zd != len: %lu)",
+                                       ret, subbuf_size);
+               }
+               break;
+       case LTTNG_EVENT_MMAP:
+               /* Get subbuffer size without padding */
+               err = kernctl_get_subbuf_size(infd, &subbuf_size);
+               if (err != 0) {
+                       errno = -err;
+                       perror("Getting sub-buffer len failed.");
+                       ret = err;
+                       goto end;
+               }
+
+               /* Make sure the tracer is not gone mad on us! */
+               assert(len >= subbuf_size);
+
+               padding = len - subbuf_size;
+
+               /* write the subbuffer to the tracefile */
+               ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, subbuf_size,
+                               padding);
+               /*
+                * The mmap operation should write subbuf_size amount of data when
+                * network streaming or the full padding (len) size when we are _not_
+                * streaming.
+                */
+               if ((ret != subbuf_size && stream->net_seq_idx != -1) ||
+                               (ret != len && stream->net_seq_idx == -1)) {
+                       /*
+                        * Display the error but continue processing to try to release the
+                        * subbuffer
+                        */
+                       ERR("Error writing to tracefile "
+                                       "(ret: %zd != len: %lu != subbuf_size: %lu)",
+                                       ret, len, subbuf_size);
+               }
+               break;
+       default:
+               ERR("Unknown output method");
+               ret = -1;
        }
 
        err = kernctl_put_next_subbuf(infd);
        if (err != 0) {
-               errno = -ret;
+               errno = -err;
                if (errno == EFAULT) {
                        perror("Error in unreserving sub buffer\n");
                } else if (errno == EIO) {
                        /* Should never happen with newer LTTng versions */
                        perror("Reader has been pushed by the writer, last sub-buffer corrupted.");
                }
+
+               ret = -err;
                goto end;
        }
 
This page took 0.026866 seconds and 4 git commands to generate.