Add strong madvise() hint for cache pruning

[fio.git] / engines / null.c

diff --git a/engines/null.c b/engines/null.c
index 1988678946ca397e8ac20c6b0532262c20c5f0bf..f434550300e7a3d454c7561b808d1cfe24372f1c 100644 (file)
--- a/engines/null.c
+++ b/engines/null.c
@@ -1,5 +1,8 @@
 /*
- * null engine - doesn't do any transfers. Used to test fio.
+ * null engine
+ *
+ * IO engine that doesn't do any real IO transfers, it just pretends to.
+ * The main purpose is to test fio itself.
  *
  */
 #include <stdio.h>
@@ -9,7 +12,6 @@
 #include <assert.h>
 
 #include "../fio.h"
-#include "../os.h"
 
 struct null_data {
        struct io_u **io_us;
@@ -24,14 +26,18 @@ static struct io_u *fio_null_event(struct thread_data *td, int event)
        return nd->io_us[event];
 }
 
-static int fio_null_getevents(struct thread_data *td, int fio_unused min,
-                             int fio_unused max, struct timespec fio_unused *t)
+static int fio_null_getevents(struct thread_data *td, unsigned int min_events,
+                             unsigned int fio_unused max,
+                             struct timespec fio_unused *t)
 {
        struct null_data *nd = td->io_ops->data;
-       int ret;
+       int ret = 0;
+       
+       if (min_events) {
+               ret = nd->events;
+               nd->events = 0;
+       }
 
-       ret = nd->events;
-       nd->events = 0;
        return ret;
 }
 
@@ -39,8 +45,12 @@ static int fio_null_commit(struct thread_data *td)
 {
        struct null_data *nd = td->io_ops->data;
 
-       nd->events = nd->queued;
-       nd->queued = 0;
+       if (!nd->events) {
+               io_u_mark_submit(td, nd->queued);
+               nd->events = nd->queued;
+               nd->queued = 0;
+       }
+
        return 0;
 }
 
@@ -48,38 +58,20 @@ static int fio_null_queue(struct thread_data fio_unused *td, struct io_u *io_u)
 {
        struct null_data *nd = td->io_ops->data;
 
+       fio_ro_check(td, io_u);
+
        if (td->io_ops->flags & FIO_SYNCIO)
                return FIO_Q_COMPLETED;
+       if (nd->events)
+               return FIO_Q_BUSY;
 
        nd->io_us[nd->queued++] = io_u;
        return FIO_Q_QUEUED;
 }
 
-static int fio_null_setup(struct thread_data *td)
-{
-       struct fio_file *f;
-       int i;
-
-       if (!td->total_file_size) {
-               log_err("fio: need size= set\n");
-               return 1;
-       }
-
-       td->io_size = td->total_file_size;
-       td->total_io_size = td->io_size;
-
-       for_each_file(td, f, i) {
-               f->real_file_size = td->total_io_size / td->nr_files;
-               f->file_size = f->real_file_size;
-       }
-
-       return 0;
-}
-
 static int fio_null_open(struct thread_data fio_unused *td,
                         struct fio_file fio_unused *f)
 {
-       f->fd = 0;
        return 0;
 }
 
@@ -91,7 +83,6 @@ static void fio_null_cleanup(struct thread_data *td)
                if (nd->io_us)
                        free(nd->io_us);
                free(nd);
-               td->io_ops->data = NULL;
        }
 }
 
@@ -101,9 +92,9 @@ static int fio_null_init(struct thread_data *td)
 
        memset(nd, 0, sizeof(*nd));
 
-       if (td->iodepth != 1) {
-               nd->io_us = malloc(td->iodepth * sizeof(struct io_u *));
-               memset(nd->io_us, 0, td->iodepth * sizeof(struct io_u *));
+       if (td->o.iodepth != 1) {
+               nd->io_us = malloc(td->o.iodepth * sizeof(struct io_u *));
+               memset(nd->io_us, 0, td->o.iodepth * sizeof(struct io_u *));
        } else
                td->io_ops->flags |= FIO_SYNCIO;
 
@@ -114,7 +105,6 @@ static int fio_null_init(struct thread_data *td)
 static struct ioengine_ops ioengine = {
        .name           = "null",
        .version        = FIO_IOOPS_VERSION,
-       .setup          = fio_null_setup,
        .queue          = fio_null_queue,
        .commit         = fio_null_commit,
        .getevents      = fio_null_getevents,