[PATCH 5/7] blk-mq: add BLK_MQ_F_NO_SCHED flag

[Jens Axboe]

Drivers can use this to prevent IO scheduling on a queue. Use this
for NVMe, for the admin queue, which doesn't handle file system
requests.

Signed-off-by: Jens Axboe <ax...@fb.com>
---
 drivers/nvme/host/pci.c | 1 +
 include/linux/blk-mq.h  | 1 +
 2 files changed, 2 insertions(+)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index d58f8e4e2c06..4560575f0a39 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1187,6 +1187,7 @@ static int nvme_alloc_admin_tags(struct nvme_dev *dev)
                dev->admin_tagset.timeout = ADMIN_TIMEOUT;
                dev->admin_tagset.numa_node = dev_to_node(dev->dev);
                dev->admin_tagset.cmd_size = nvme_cmd_size(dev);
+               dev->admin_tagset.flags = BLK_MQ_F_NO_SCHED;
                dev->admin_tagset.driver_data = dev;
 
                if (blk_mq_alloc_tag_set(&dev->admin_tagset))
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 35a0af5ede6d..a85bd83bb218 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -151,6 +151,7 @@ enum {
        BLK_MQ_F_SG_MERGE       = 1 << 2,
        BLK_MQ_F_DEFER_ISSUE    = 1 << 4,
        BLK_MQ_F_BLOCKING       = 1 << 5,
+       BLK_MQ_F_NO_SCHED       = 1 << 6,
        BLK_MQ_F_ALLOC_POLICY_START_BIT = 8,
        BLK_MQ_F_ALLOC_POLICY_BITS = 1,
 
-- 
2.7.4