Add option for refilling IO buffers on each submit

[fio.git] / io_u.c

diff --git a/io_u.c b/io_u.c
index 92cdd71701a9df3973eb4158b0a8fcb6bab4eed5..06fb3cef80c7fb71c1c6aad29e1936b27e1b9b19 100644 (file)
--- a/io_u.c
+++ b/io_u.c
@@ -6,6 +6,7 @@
 #include <assert.h>
 
 #include "fio.h"
+#include "hash.h"
 
 /*
  * Change this define to play with the timeout handling
@@ -780,6 +781,9 @@ struct io_u *get_io_u(struct thread_data *td)
        io_u->endpos = io_u->offset + io_u->buflen;
        io_u->xfer_buf = io_u->buf;
        io_u->xfer_buflen = io_u->buflen;
+
+       if (td->o.refill_buffers && io_u->ddir == DDIR_WRITE)
+               io_u_fill_buffer(td, io_u, io_u->xfer_buflen);
 out:
        if (!td_io_prep(td, io_u)) {
                fio_gettime(&io_u->start_time, NULL);
@@ -943,6 +947,23 @@ void io_u_queued(struct thread_data *td, struct io_u *io_u)
        add_slat_sample(td, io_u->ddir, slat_time);
 }
 
+/*
+ * "randomly" fill the buffer contents
+ */
+void io_u_fill_buffer(struct thread_data *td, struct io_u *io_u,
+                     unsigned int max_bs)
+{
+       long *ptr = io_u->buf;
+
+       if (!td->o.zero_buffers) {
+               while ((void *) ptr - io_u->buf < max_bs) {
+                       *ptr = rand() * GOLDEN_RATIO_PRIME;
+                       ptr++;
+               }
+       } else
+               memset(ptr, 0, max_bs);
+}
+
 #ifdef FIO_USE_TIMEOUT
 void io_u_set_timeout(struct thread_data *td)
 {