backend: cleanup overlap submission logic

[fio.git] / backend.c

diff --git a/backend.c b/backend.c
index fe1599706fcdcb32b0990b1e840b3259448396ab..d2675b43cfd3b9900636ecb76ea8c96f82817352 100644 (file)
--- a/backend.c
+++ b/backend.c
@@ -586,6 +586,50 @@ static int unlink_all_files(struct thread_data *td)
        return ret;
 }
 
+/*
+ * Check if io_u will overlap an in-flight IO in the queue
+ */
+static bool in_flight_overlap(struct io_u_queue *q, struct io_u *io_u)
+{
+       bool overlap;
+       struct io_u *check_io_u;
+       unsigned long long x1, x2, y1, y2;
+       int i;
+
+       x1 = io_u->offset;
+       x2 = io_u->offset + io_u->buflen;
+       overlap = false;
+       io_u_qiter(q, check_io_u, i) {
+               if (check_io_u->flags & IO_U_F_FLIGHT) {
+                       y1 = check_io_u->offset;
+                       y2 = check_io_u->offset + check_io_u->buflen;
+
+                       if (x1 < y2 && y1 < x2) {
+                               overlap = true;
+                               dprint(FD_IO, "in-flight overlap: %llu/%lu, %llu/%lu\n",
+                                               x1, io_u->buflen,
+                                               y1, check_io_u->buflen);
+                               break;
+                       }
+               }
+       }
+
+       return overlap;
+}
+
+static int io_u_submit(struct thread_data *td, struct io_u *io_u)
+{
+       /*
+        * Check for overlap if the user asked us to, and we have
+        * at least one IO in flight besides this one.
+        */
+       if (td->o.serialize_overlap && td->cur_depth > 1 &&
+           in_flight_overlap(&td->io_u_all, io_u))
+               return FIO_Q_BUSY;
+
+       return td_io_queue(td, io_u);
+}
+
 /*
  * The main verify engine. Runs over the writes we previously submitted,
  * reads the blocks back in, and checks the crc/md5 of the data.
@@ -716,7 +760,7 @@ static void do_verify(struct thread_data *td, uint64_t verify_bytes)
                if (!td->o.disable_slat)
                        fio_gettime(&io_u->start_time, NULL);
 
-               ret = td_io_queue(td, io_u);
+               ret = io_u_submit(td, io_u);
 
                if (io_queue_event(td, io_u, &ret, ddir, NULL, 1, NULL))
                        break;
@@ -983,7 +1027,7 @@ static void do_io(struct thread_data *td, uint64_t *bytes_done)
                                td->rate_next_io_time[ddir] = usec_for_io(td, ddir);
 
                } else {
-                       ret = td_io_queue(td, io_u);
+                       ret = io_u_submit(td, io_u);
 
                        if (should_check_rate(td))
                                td->rate_next_io_time[ddir] = usec_for_io(td, ddir);