It is not possible to maintain sustained per-thread iodepth in ZBD mode.
The way code is written, "max_open_zones" acts as a global limit, and
once one or few threads open all "max_open_zones" zones, other threads
can't open anything and _exit_ prematurely.
This config is guaranteed to make equal number of zone resets/IO now:
each thread generates identical pattern and doesn't intersect with other
threads:
zonemode=zbd
zonesize=...
rw=write
numjobs=N
offset_increment=M*zonesize
[j]
size=M*zonesize
Patch introduces "job_max_open_zones" which is per-thread/process limit.
"max_open_zones" remains per file/device limit. Both limits are checked
for each open zone so one thread can't kick out others.
Signed-off-by: Alexey Dobriyan (SK hynix) <adobriyan@xxxxxxxxx>
Reviewed-by: Damien Le Moal <damien.lemoal@xxxxxxx>
---
fio.1 | 6 +++++-
fio.h | 1 +
options.c | 16 +++++++++++++---
thread_options.h | 1 +
zbd.c | 46 +++++++++++++++++++++++++++++++++++-----------
zbd.h | 3 +++
6 files changed, 58 insertions(+), 15 deletions(-)
diff --git a/fio.1 b/fio.1
index c905e9ae..47bc1592 100644
--- a/fio.1
+++ b/fio.1
@@ -804,7 +804,11 @@ so. Default: false.
When running a random write test across an entire drive many more zones will be
open than in a typical application workload. Hence this command line option
that allows to limit the number of open zones. The number of open zones is
-defined as the number of zones to which write commands are issued.
+defined as the number of zones to which write commands are issued by all
+threads/processes.
+.TP
+.BI job_max_open_zones \fR=\fPint
+Limit on the number of simultaneously opened zones per single thread/process.
.TP
.BI zone_reset_threshold \fR=\fPfloat
A number between zero and one that indicates the ratio of logical blocks with
diff --git a/fio.h b/fio.h
index d496e7f2..8045c32f 100644
--- a/fio.h
+++ b/fio.h
@@ -260,6 +260,7 @@ struct thread_data {
struct frand_state prio_state;
struct zone_split_index **zone_state_index;
+ unsigned int num_open_zones;
unsigned int verify_batch;
unsigned int trim_batch;
diff --git a/options.c b/options.c
index da401aed..f2d98fa6 100644
--- a/options.c
+++ b/options.c
@@ -3360,12 +3360,22 @@ struct fio_option fio_options[FIO_MAX_OPTS] = {
},
{
.name = "max_open_zones",
- .lname = "Maximum number of open zones",
+ .lname = "Per device/file maximum number of open zones",
.type = FIO_OPT_INT,
.off1 = offsetof(struct thread_options, max_open_zones),
.maxval = ZBD_MAX_OPEN_ZONES,
- .help = "Limit random writes to SMR drives to the specified"
- " number of sequential zones",
+ .help = "Limit on the number of simultaneously opened sequential write zones with zonemode=zbd",
+ .def = "0",
+ .category = FIO_OPT_C_IO,
+ .group = FIO_OPT_G_INVALID,
+ },
+ {
+ .name = "job_max_open_zones",
+ .lname = "Job maximum number of open zones",
+ .type = FIO_OPT_INT,
+ .off1 = offsetof(struct thread_options, job_max_open_zones),
+ .maxval = ZBD_MAX_OPEN_ZONES,
+ .help = "Limit on the number of simultaneously opened sequential write zones with zonemode=zbd by one thread/process",
.def = "0",
.category = FIO_OPT_C_IO,
.group = FIO_OPT_G_INVALID,
diff --git a/thread_options.h b/thread_options.h
index 09ccd5b2..968ea0ab 100644
--- a/thread_options.h
+++ b/thread_options.h
@@ -343,6 +343,7 @@ struct thread_options {
/* Parameters that affect zonemode=zbd */
unsigned int read_beyond_wp;
int max_open_zones;
+ unsigned int job_max_open_zones;
fio_fp64_t zrt;
fio_fp64_t zrf;
};
diff --git a/zbd.c b/zbd.c
index 7185d85c..61c685a1 100644
--- a/zbd.c
+++ b/zbd.c
@@ -548,8 +548,10 @@ static int zbd_create_zone_info(struct thread_data *td, struct fio_file *f)
return -EINVAL;
}
- if (ret == 0)
+ if (ret == 0) {
f->zbd_info->model = zbd_model;
+ f->zbd_info->max_open_zones = td->o.max_open_zones;
+ }
return ret;
}
@@ -623,6 +625,25 @@ int zbd_setup_files(struct thread_data *td)
if (!zbd_verify_bs())
return 1;
+ for_each_file(td, f, i) {
+ struct zoned_block_device_info *zbd = f->zbd_info;
+
+ if (!zbd)
+ continue;
+
+ zbd->max_open_zones = zbd->max_open_zones ?: ZBD_MAX_OPEN_ZONES;
+
+ if (td->o.max_open_zones > 0 &&
+ zbd->max_open_zones != td->o.max_open_zones) {
+ log_err("Different 'max_open_zones' values\n");
+ return 1;
+ }
+ if (zbd->max_open_zones > ZBD_MAX_OPEN_ZONES) {
+ log_err("'max_open_zones' value is limited by %u\n", ZBD_MAX_OPEN_ZONES);
+ return 1;
+ }
+ }
+
return 0;
}
@@ -710,6 +731,7 @@ static void zbd_close_zone(struct thread_data *td, const struct fio_file *f,
(ZBD_MAX_OPEN_ZONES - (open_zone_idx + 1)) *
sizeof(f->zbd_info->open_zones[0]));
f->zbd_info->num_open_zones--;
+ td->num_open_zones--;
f->zbd_info->zone_info[zone_idx].open = 0;
}
@@ -887,8 +909,9 @@ static bool is_zone_open(const struct thread_data *td, const struct fio_file *f,
struct zoned_block_device_info *zbdi = f->zbd_info;
int i;
- assert(td->o.max_open_zones <= ARRAY_SIZE(zbdi->open_zones));
- assert(zbdi->num_open_zones <= td->o.max_open_zones);
+ assert(td->o.job_max_open_zones == 0 || td->num_open_zones <= td->o.job_max_open_zones);
+ assert(td->o.job_max_open_zones <= zbdi->max_open_zones);
+ assert(zbdi->num_open_zones <= zbdi->max_open_zones);
for (i = 0; i < zbdi->num_open_zones; i++)
if (zbdi->open_zones[i] == zone_idx)
@@ -921,18 +944,19 @@ static bool zbd_open_zone(struct thread_data *td, const struct io_u *io_u,
if (td->o.verify != VERIFY_NONE && zbd_zone_full(f, z, min_bs))
return false;
- /* Zero means no limit */
- if (!td->o.max_open_zones)
- return true;
-
pthread_mutex_lock(&f->zbd_info->mutex);
if (is_zone_open(td, f, zone_idx))
goto out;
res = false;
- if (f->zbd_info->num_open_zones >= td->o.max_open_zones)
+ /* Zero means no limit */
+ if (td->o.job_max_open_zones > 0 &&
+ td->num_open_zones >= td->o.job_max_open_zones)
+ goto out;
+ if (f->zbd_info->num_open_zones >= f->zbd_info->max_open_zones)
goto out;
dprint(FD_ZBD, "%s: opening zone %d\n", f->file_name, zone_idx);
f->zbd_info->open_zones[f->zbd_info->num_open_zones++] = zone_idx;
+ td->num_open_zones++;
z->open = 1;
res = true;
@@ -967,7 +991,7 @@ static struct fio_zone_info *zbd_convert_to_open_zone(struct thread_data *td,
assert(is_valid_offset(f, io_u->offset));
- if (td->o.max_open_zones) {
+ if (td->o.job_max_open_zones) {
/*
* This statement accesses f->zbd_info->open_zones[] on purpose
* without locking.
@@ -996,7 +1020,7 @@ static struct fio_zone_info *zbd_convert_to_open_zone(struct thread_data *td,
zone_lock(td, f, z);
pthread_mutex_lock(&f->zbd_info->mutex);
- if (td->o.max_open_zones == 0)
+ if (td->o.job_max_open_zones == 0)
goto examine_zone;
if (f->zbd_info->num_open_zones == 0) {
pthread_mutex_unlock(&f->zbd_info->mutex);
@@ -1052,7 +1076,7 @@ examine_zone:
}
dprint(FD_ZBD, "%s(%s): closing zone %d\n", __func__, f->file_name,
zone_idx);
- if (td->o.max_open_zones)
+ if (td->o.job_max_open_zones)
zbd_close_zone(td, f, open_zone_idx);
pthread_mutex_unlock(&f->zbd_info->mutex);
diff --git a/zbd.h b/zbd.h
index e8dd3d6d..9c447af4 100644
--- a/zbd.h
+++ b/zbd.h
@@ -45,6 +45,8 @@ struct fio_zone_info {
/**
* zoned_block_device_info - zoned block device characteristics
* @model: Device model.
+ * @max_open_zones: global limit on the number of simultaneously opened
+ * sequential write zones.
* @mutex: Protects the modifiable members in this structure (refcount and
* num_open_zones).
* @zone_size: size of a single zone in units of 512 bytes
@@ -65,6 +67,7 @@ struct fio_zone_info {
*/
struct zoned_block_device_info {
enum zbd_zoned_model model;
+ uint32_t max_open_zones;
pthread_mutex_t mutex;
uint64_t zone_size;
uint64_t sectors_with_data;
--
2.26.2
