Add low water mark for queuing depth
[fio.git] / filesetup.c
index 610981b437594d32c90587178b323c2ce6dcc348..84cd7f7dfe2bffa93ed62d3ea7aaa790cd6e02b3 100644 (file)
@@ -15,7 +15,7 @@ static int file_ok(struct thread_data *td, struct fio_file *f)
 {
        struct stat st;
 
-       if (td->filetype != FIO_TYPE_FILE)
+       if (td->filetype != FIO_TYPE_FILE || (td->io_ops->flags & FIO_NULLIO))
                return 0;
 
        if (stat(f->file_name, &st) == -1)
@@ -154,6 +154,16 @@ static int file_size(struct thread_data *td, struct fio_file *f)
 {
        struct stat st;
 
+       /*
+        * if we are not doing real io, just pretend the file is as large
+        * as the size= given. this works fine with nrfiles > 1 as well,
+        * we only really care about it being at least as big as size=
+        */
+       if (td->io_ops->flags & FIO_NULLIO) {
+               f->real_file_size = f->file_size = td->total_file_size;
+               return 0;
+       }
+
        if (td->overwrite) {
                if (fstat(f->fd, &st) == -1) {
                        td_verror(td, errno);
@@ -332,29 +342,38 @@ static int setup_file(struct thread_data *td, struct fio_file *f)
 
        if (td->io_ops->flags & FIO_NETIO)
                return 0;
-       if (td->odirect)
-               flags |= OS_O_DIRECT;
-       if (td->sync_io)
-               flags |= O_SYNC;
 
-       if (td_write(td) || td_rw(td)) {
-               flags |= O_RDWR;
+       /*
+        * we need a valid file descriptor, but don't create a real file.
+        * lets just dup stdout, seems like a sensible approach.
+        */
+       if (td->io_ops->flags & FIO_NULLIO)
+               f->fd = dup(STDOUT_FILENO);
+       else {
+               if (td->odirect)
+                       flags |= OS_O_DIRECT;
+               if (td->sync_io)
+                       flags |= O_SYNC;
+
+               if (td_write(td) || td_rw(td)) {
+                       flags |= O_RDWR;
 
-               if (td->filetype == FIO_TYPE_FILE) {
-                       if (!td->overwrite)
-                               flags |= O_TRUNC;
+                       if (td->filetype == FIO_TYPE_FILE) {
+                               if (!td->overwrite)
+                                       flags |= O_TRUNC;
 
-                       flags |= O_CREAT;
-               }
+                               flags |= O_CREAT;
+                       }
 
-               f->fd = open(f->file_name, flags, 0600);
-       } else {
-               if (td->filetype == FIO_TYPE_CHAR)
-                       flags |= O_RDWR;
-               else
-                       flags |= O_RDONLY;
+                       f->fd = open(f->file_name, flags, 0600);
+               } else {
+                       if (td->filetype == FIO_TYPE_CHAR)
+                               flags |= O_RDWR;
+                       else
+                               flags |= O_RDONLY;
 
-               f->fd = open(f->file_name, flags);
+                       f->fd = open(f->file_name, flags);
+               }
        }
 
        if (f->fd == -1) {