[S390] qdio: add counter for input queue full condition

Add a counter to the qdio performance statistics that indicates that no
free buffers were left in the input queue. If the counter gets increased
it means that the qdio adapter filled all available buffers and possibly
had more buffers ready but could not transmit them.

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

3 files changed, 5 insertions, 1 deletions

diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c
index 4be6e84b959..b2275c5000e 100644
--- a/drivers/s390/cio/qdio_main.c
+++ b/drivers/s390/cio/qdio_main.c
@@ -486,7 +486,8 @@ static int get_inbound_buffer_frontier(struct qdio_q *q)
         case SLSB_P_INPUT_PRIMED:
                 inbound_primed(q, count);
                 q->first_to_check = add_buf(q->first_to_check, count);
-                atomic_sub(count, &q->nr_buf_used);
+                if (atomic_sub(count, &q->nr_buf_used) == 0)
+                        qdio_perf_stat_inc(&perf_stats.inbound_queue_full);
                 break;
         case SLSB_P_INPUT_ERROR:
                 announce_buffer_error(q, count);
diff --git a/drivers/s390/cio/qdio_perf.c b/drivers/s390/cio/qdio_perf.c
index 968e3c7c263..54f7c325a3e 100644
--- a/drivers/s390/cio/qdio_perf.c
+++ b/drivers/s390/cio/qdio_perf.c
@@ -64,6 +64,8 @@ static int qdio_perf_proc_show(struct seq_file *m, void *v)
                    (long)atomic_long_read(&perf_stats.fast_requeue));
         seq_printf(m, "Number of outbound target full condition\t: %li\n",
                    (long)atomic_long_read(&perf_stats.outbound_target_full));
+        seq_printf(m, "Number of inbound queue full condition\t\t: %li\n",
+                   (long)atomic_long_read(&perf_stats.inbound_queue_full));
         seq_printf(m, "Number of outbound tasklet mod_timer calls\t: %li\n",
                    (long)atomic_long_read(&perf_stats.debug_tl_out_timer));
         seq_printf(m, "Number of stop polling calls\t\t\t: %li\n",
diff --git a/drivers/s390/cio/qdio_perf.h b/drivers/s390/cio/qdio_perf.h
index ff4504ce1e3..12454231dc8 100644
--- a/drivers/s390/cio/qdio_perf.h
+++ b/drivers/s390/cio/qdio_perf.h
@@ -36,6 +36,7 @@ struct qdio_perf_stats {
         atomic_long_t outbound_handler;
         atomic_long_t fast_requeue;
         atomic_long_t outbound_target_full;
+        atomic_long_t inbound_queue_full;
 
         /* for debugging */
         atomic_long_t debug_tl_out_timer;