On 03/16/2012 04:12 AM, Dan Ehrenberg wrote:
> Previously, when fio had written a volume of I/O equal to the size
> argument, it restarted the main do_io loop.
>
> This patch allows time_based tests to be run for longer than one
> cycle in the do_io main loop. This has a couple of advantages:
> * The random number generator is not reset on each iteration
> of the loop, so running longer will reach different locations.
> * There is not a throughput-reducing point where all operations
> must be reaped before new operations are submitted.
>
> The implementation consists of two minor changes:
> * In the do_io loop, a time_based test will not exit the loop for
> reading or writing too much data.
> * When reading or writing sequentially, the operations wrap around
> to the beginning after reading the end within the
> get_next_seq_block function.
This looks good, but one question - does it really behave with random
IO, when the random map is enabled? I set write_iolog and looked at the
patterns. From the beginning:
foo.1.0 add
foo.1.0 open
foo.1.0 read 8093696 4096
foo.1.0 read 99356672 4096
foo.1.0 read 113164288 4096
[...]
foo.1.0 close
foo.1.0 open
foo.1.0 read 8093696 4096
foo.1.0 read 99356672 4096
foo.1.0 read 113164288 4096
[...]
etc. So it's definitely repeating the same sequence there. We don't want
to close/open the file for this case either, how does the below
look/work for you? It's your patch, and an update in
get_next_rand_block() to handle this case too.
diff --git a/backend.c b/backend.c
index 7343286..1d9b0a2 100644
--- a/backend.c
+++ b/backend.c
@@ -555,7 +555,8 @@ static void do_io(struct thread_data *td)
td_set_runstate(td, TD_RUNNING);
while ((td->o.read_iolog_file && !flist_empty(&td->io_log_list)) ||
- (!flist_empty(&td->trim_list)) || !io_bytes_exceeded(td)) {
+ (!flist_empty(&td->trim_list)) || !io_bytes_exceeded(td) ||
+ td->o.time_based) {
struct timeval comp_time;
unsigned long bytes_done[2] = { 0, 0 };
int min_evts = 0;
diff --git a/io_u.c b/io_u.c
index 20794c3..3bda0e6 100644
--- a/io_u.c
+++ b/io_u.c
@@ -238,13 +238,18 @@ ret:
static int get_next_rand_block(struct thread_data *td, struct fio_file *f,
enum fio_ddir ddir, unsigned long long *b)
{
- if (get_next_rand_offset(td, f, ddir, b)) {
- dprint(FD_IO, "%s: rand offset failed, last=%llu, size=%llu\n",
- f->file_name, f->last_pos, f->real_file_size);
- return 1;
+ if (!get_next_rand_offset(td, f, ddir, b))
+ return 0;
+
+ if (td->o.time_based) {
+ fio_file_reset(f);
+ if (!get_next_rand_offset(td, f, ddir, b))
+ return 0;
}
- return 0;
+ dprint(FD_IO, "%s: rand offset failed, last=%llu, size=%llu\n",
+ f->file_name, f->last_pos, f->real_file_size);
+ return 1;
}
static int get_next_seq_block(struct thread_data *td, struct fio_file *f,
@@ -252,6 +257,9 @@ static int get_next_seq_block(struct thread_data *td, struct fio_file *f,
{
assert(ddir_rw(ddir));
+ if (f->last_pos >= f->io_size && td->o.time_based)
+ f->last_pos = f->last_pos - f->io_size;
+
if (f->last_pos < f->real_file_size) {
unsigned long long pos;
--
Jens Axboe
--
To unsubscribe from this list: send the line "unsubscribe fio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
