UST synchronization fix

[ust.git] / libust / buffers.c

diff --git a/libust/buffers.c b/libust/buffers.c
index 7b540de880ee68934c80fb8fb19d392b91beb180..c27b78877df625c33a23af1ff8f6af2f4277ad1b 100644 (file)
--- a/libust/buffers.c
+++ b/libust/buffers.c
@@ -771,26 +771,6 @@ 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 +793,7 @@ 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 +858,7 @@ 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 +887,7 @@ 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 +932,7 @@ 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,