@@ -111,6 +111,7 @@ struct tcmu_dev {
struct kref kref;
struct se_device se_dev;
+ struct se_dev_plug se_plug;
char *name;
struct se_hba *hba;
@@ -119,6 +120,7 @@ struct tcmu_dev {
#define TCMU_DEV_BIT_BROKEN 1
#define TCMU_DEV_BIT_BLOCKED 2
#define TCMU_DEV_BIT_TMR_NOTIFY 3
+#define TCM_DEV_BIT_PLUGGED 4
unsigned long flags;
struct uio_info uio_info;
@@ -959,6 +961,25 @@ static uint32_t ring_insert_padding(struct tcmu_dev *udev, size_t cmd_size)
return cmd_head;
}
+static void tcmu_unplug_device(struct se_dev_plug *se_plug)
+{
+ struct se_device *se_dev = se_plug->se_dev;
+ struct tcmu_dev *udev = TCMU_DEV(se_dev);
+
+ clear_bit(TCM_DEV_BIT_PLUGGED, &udev->flags);
+ uio_event_notify(&udev->uio_info);
+}
+
+static struct se_dev_plug *tcmu_plug_device(struct se_device *se_dev)
+{
+ struct tcmu_dev *udev = TCMU_DEV(se_dev);
+
+ if (!test_and_set_bit(TCM_DEV_BIT_PLUGGED, &udev->flags))
+ return &udev->se_plug;
+
+ return NULL;
+}
+
/**
* queue_cmd_ring - queue cmd to ring or internally
* @tcmu_cmd: cmd to queue
@@ -1086,8 +1107,8 @@ static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err)
list_add_tail(&tcmu_cmd->queue_entry, &udev->inflight_queue);
- /* TODO: only if FLUSH and FUA? */
- uio_event_notify(&udev->uio_info);
+ if (!test_bit(TCM_DEV_BIT_PLUGGED, &udev->flags))
+ uio_event_notify(&udev->uio_info);
return 0;
@@ -2840,6 +2861,8 @@ static struct target_backend_ops tcmu_ops = {
.configure_device = tcmu_configure_device,
.destroy_device = tcmu_destroy_device,
.free_device = tcmu_free_device,
+ .unplug_device = tcmu_unplug_device,
+ .plug_device = tcmu_plug_device,
.parse_cdb = tcmu_parse_cdb,
.tmr_notify = tcmu_tmr_notify,
.set_configfs_dev_params = tcmu_set_configfs_dev_params,
This patch adds plug/unplug callouts for tcmu, so we can avoid the number of times we switch to userspace. Using this driver with tcm loop is a common config, and dependng on the nr_hw_queues (nr_hw_queues=1 performs much better) and fio jobs (lower num jobs around 4) this patch can increase IOPs by only around 5-10% because we hit other issues like the big per tcmu device mutex. Signed-off-by: Mike Christie <michael.christie@oracle.com> --- drivers/target/target_core_user.c | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-)