Hi,
I was trying to use the async_verify option. Looks like if we use this
option for synchronous I/O, then it really doesnt do anything as after
every I/O is completed, we still need the asynchronous verify thread
to complete the verification and release the io_u so the main thread
can allocate this io_u for the next I/O. So to remove this bottle neck
I added a new option extra_buff_count. This takes an integer and the
code will allocate that many more extra io_us. This way when the main
thread has completed the I/O it will have extra io_u and buffers to
issue more I/Os while the asynchronous verify threads do their job.
This can be used with both synchronous and libaio contexts.
Thanks
-radha
diff --git a/HOWTO b/HOWTO
index cdd6473..71efd10 100644
--- a/HOWTO
+++ b/HOWTO
@@ -872,7 +872,12 @@ verify_async=int Fio will normally verify IO inline from the submitting
verify_async_cpus=str Tell fio to set the given CPU affinity on the
async IO verification threads. See cpus_allowed for the
format used.
-
+
+extra_buff_count=int Allocate extra I/O buffers to continue issuing
+ IO to the file/device. This can be used to keep the device
+ busy with I/Os while the data verification is being
+ done asynchronously.
+
stonewall Wait for preceeding jobs in the job file to exit, before
starting this one. Can be used to insert serialization
points in the job file. A stone wall also implies starting
diff --git a/fio.1 b/fio.1
index 4445d0a..8bee99d 100644
--- a/fio.1
+++ b/fio.1
@@ -627,6 +627,11 @@ allows them to have IO in flight while verifies are running.
Tell fio to set the given CPU affinity on the async IO verification threads.
See \fBcpus_allowed\fP for the format used.
.TP
+.BI extra_buff_count \fR=\fPint
+Allocate extra I/O buffers to continue issuing IO to the file/device.
+This can be used to keep the device busy with I/Os while the data verification
+is being done asynchronously.
+.TP
.B stonewall
Wait for preceeding jobs in the job file to exit before starting this one.
\fBstonewall\fR implies \fBnew_group\fR.
diff --git a/fio.c b/fio.c
index 8f8bb56..ff8d0e7 100644
--- a/fio.c
+++ b/fio.c
@@ -534,7 +534,8 @@ sync_done:
* if we can queue more, do so. but check if there are
* completed io_u's first.
*/
- full = queue_full(td) || ret == FIO_Q_BUSY;
+ full = queue_full(td) || ret == FIO_Q_BUSY ||
+ td->cur_depth == td->o.iodepth;
if (full || !td->o.iodepth_batch_complete) {
min_events = td->o.iodepth_batch_complete;
if (full && !min_events)
@@ -686,7 +687,8 @@ sync_done:
/*
* See if we need to complete some commands
*/
- full = queue_full(td) || ret == FIO_Q_BUSY;
+ full = queue_full(td) || ret == FIO_Q_BUSY ||
+ td->cur_depth == td->o.iodepth;
if (full || !td->o.iodepth_batch_complete) {
min_evts = td->o.iodepth_batch_complete;
if (full && !min_evts)
@@ -787,7 +789,7 @@ static int init_io_u(struct thread_data *td)
int cl_align, i, max_units;
char *p;
- max_units = td->o.iodepth;
+ max_units = td->o.iodepth + td->o.extra_buff_count;
max_bs = max(td->o.max_bs[DDIR_READ], td->o.max_bs[DDIR_WRITE]);
td->orig_buffer_size = (unsigned long long) max_bs
* (unsigned long long) max_units;
diff --git a/fio.h b/fio.h
index e4ed76f..833a03b 100644
--- a/fio.h
+++ b/fio.h
@@ -181,6 +181,7 @@ struct thread_options {
unsigned int verify_pattern_bytes;
unsigned int verify_fatal;
unsigned int verify_async;
+ unsigned int extra_buff_count;
unsigned int use_thread;
unsigned int unlink;
unsigned int do_disk_util;
diff --git a/options.c b/options.c
index 5b88255..71f26fb 100644
--- a/options.c
+++ b/options.c
@@ -1337,6 +1337,13 @@ static struct fio_option options[] = {
},
#endif
{
+ .name = "extra_buff_count",
+ .type = FIO_OPT_INT,
+ .off1 = td_var_offset(extra_buff_count),
+ .def = "0",
+ .help = "Number of extra buffers to allocate",
+ },
+ {
.name = "write_iolog",
.type = FIO_OPT_STR_STORE,
.off1 = td_var_offset(write_iolog_file),
