tracectl cleanup v3

[ust.git] / libust / buffers.c

diff --git a/libust/buffers.c b/libust/buffers.c
index 7b540de880ee68934c80fb8fb19d392b91beb180..374ec613240fde5028fbac694b9a4d49a22c20c8 100644 (file)
--- a/libust/buffers.c
+++ b/libust/buffers.c
@@ -70,28 +70,68 @@ static int get_n_cpus(void)
        return n_cpus;
 }
 
-/* _ust_buffers_write()
+/**
+ * _ust_buffers_strncpy_fixup - Fix an incomplete string in a ltt_relay buffer.
+ * @buf : buffer
+ * @offset : offset within the buffer
+ * @len : length to write
+ * @copied: string actually copied
+ * @terminated: does string end with \0
  *
- * @buf: destination buffer
- * @offset: offset in destination
- * @src: source buffer
- * @len: length of source
- * @cpy: already copied
+ * Fills string with "X" if incomplete.
  */
-
-void _ust_buffers_write(struct ust_buffer *buf, size_t offset,
-        const void *src, size_t len, ssize_t cpy)
+void _ust_buffers_strncpy_fixup(struct ust_buffer *buf, size_t offset,
+                               size_t len, size_t copied, int terminated)
 {
-       do {
-               len -= cpy;
-               src += cpy;
-               offset += cpy;
+       size_t buf_offset, cpy;
+
+       if (copied == len) {
+               /*
+                * Deal with non-terminated string.
+                */
+               assert(!terminated);
+               offset += copied - 1;
+               buf_offset = BUFFER_OFFSET(offset, buf->chan);
+               /*
+                * Underlying layer should never ask for writes across
+                * subbuffers.
+                */
+               assert(buf_offset
+                      < buf->chan->subbuf_size*buf->chan->subbuf_cnt);
+               ust_buffers_do_memset(buf->buf_data + buf_offset, '\0', 1);
+               return;
+       }
+
+       /*
+        * Deal with incomplete string.
+        * Overwrite string's \0 with X too.
+        */
+       cpy = copied - 1;
+       assert(terminated);
+       len -= cpy;
+       offset += cpy;
+       buf_offset = BUFFER_OFFSET(offset, buf->chan);
+
+       /*
+        * Underlying layer should never ask for writes across subbuffers.
+        */
+       assert(buf_offset
+              < buf->chan->subbuf_size*buf->chan->subbuf_cnt);
 
-               WARN_ON(offset >= buf->buf_size);
+       ust_buffers_do_memset(buf->buf_data + buf_offset,
+                             'X', len);
 
-               cpy = min_t(size_t, len, buf->buf_size - offset);
-               ust_buffers_do_copy(buf->buf_data + offset, src, cpy);
-       } while (unlikely(len != cpy));
+       /*
+        * Overwrite last 'X' with '\0'.
+        */
+       offset += len - 1;
+       buf_offset = BUFFER_OFFSET(offset, buf->chan);
+       /*
+        * Underlying layer should never ask for writes across subbuffers.
+        */
+       assert(buf_offset
+              < buf->chan->subbuf_size*buf->chan->subbuf_cnt);
+       ust_buffers_do_memset(buf->buf_data + buf_offset, '\0', 1);
 }
 
 static int ust_buffers_init_buffer(struct ust_trace *trace,
@@ -737,11 +777,11 @@ static int ust_buffers_create_channel(const char *trace_name, struct ust_trace *
        ltt_chan->commit_count_mask = (~0UL >> ltt_chan->n_subbufs_order);
        ltt_chan->n_cpus = get_n_cpus();
 //ust//        ltt_chan->buf = percpu_alloc_mask(sizeof(struct ltt_channel_buf_struct), GFP_KERNEL, cpu_possible_map);
-       ltt_chan->buf = (void *) malloc(ltt_chan->n_cpus * sizeof(void *));
+       ltt_chan->buf = (void *) zmalloc(ltt_chan->n_cpus * sizeof(void *));
        if(ltt_chan->buf == NULL) {
                goto error;
        }
-       ltt_chan->buf_struct_shmids = (int *) malloc(ltt_chan->n_cpus * sizeof(int));
+       ltt_chan->buf_struct_shmids = (int *) zmalloc(ltt_chan->n_cpus * sizeof(int));
        if(ltt_chan->buf_struct_shmids == NULL)
                goto free_buf;
 
@@ -771,26 +811,6 @@ error:
        return -1;
 }
 
-/*
- * LTTng channel flush function.
- *
- * Must be called when no tracing is active in the channel, because of
- * accesses across CPUs.
- */
-static notrace void ltt_relay_buffer_flush(struct ust_buffer *buf)
-{
-       int result;
-
-//ust//        buf->finalized = 1;
-       ltt_force_switch(buf, FORCE_FLUSH);
-
-       result = write(buf->data_ready_fd_write, "1", 1);
-       if(result == -1) {
-               PERROR("write (in ltt_relay_buffer_flush)");
-               ERR("this should never happen!");
-       }
-}
-
 static void ltt_relay_async_wakeup_chan(struct ust_channel *ltt_channel)
 {
 //ust//        unsigned int i;
@@ -813,7 +833,7 @@ static void ltt_relay_finish_buffer(struct ust_channel *channel, unsigned int cp
 
        if (channel->buf[cpu]) {
                struct ust_buffer *buf = channel->buf[cpu];
-               ltt_relay_buffer_flush(buf);
+               ltt_force_switch(buf, FORCE_FLUSH);
 //ust//                ltt_relay_wake_writers(ltt_buf);
                /* closing the pipe tells the consumer the buffer is finished */
                
@@ -878,7 +898,7 @@ static void ltt_reserve_switch_old_subbuf(
         * This compiler barrier is upgraded into a smp_wmb() by the IPI
         * sent by get_subbuf() when it does its smp_rmb().
         */
-       barrier();
+       smp_wmb();
        uatomic_add(&buf->commit_count[oldidx].cc, padding_size);
        commit_count = uatomic_read(&buf->commit_count[oldidx].cc);
        ltt_check_deliver(chan, buf, offsets->old - 1, commit_count, oldidx);
@@ -907,7 +927,7 @@ static void ltt_reserve_switch_new_subbuf(
         * This compiler barrier is upgraded into a smp_wmb() by the IPI
         * sent by get_subbuf() when it does its smp_rmb().
         */
-       barrier();
+       smp_wmb();
        uatomic_add(&buf->commit_count[beginidx].cc, ltt_subbuffer_header_size());
        commit_count = uatomic_read(&buf->commit_count[beginidx].cc);
        /* Check if the written buffer has to be delivered */
@@ -952,7 +972,7 @@ static void ltt_reserve_end_switch_current(
         * This compiler barrier is upgraded into a smp_wmb() by the IPI
         * sent by get_subbuf() when it does its smp_rmb().
         */
-       barrier();
+       smp_wmb();
        uatomic_add(&buf->commit_count[endidx].cc, padding_size);
        commit_count = uatomic_read(&buf->commit_count[endidx].cc);
        ltt_check_deliver(chan, buf,