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| author | Gioh Kim <gi-oh.kim@cloud.ionos.com> | 2021-04-19 10:37:16 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-04-20 17:59:04 +0300 |
| commit | 2958a995edc94654df690318df7b9b49e5a3ef88 (patch) | |
| tree | fddb6e4b38e52bfcc2a984940fa0b65e61292252 /drivers/block/rnbd/rnbd-clt.h | |
| parent | 12b06533104e802df73c1fbe159437c19933d6c0 (diff) | |
| download | linux-2958a995edc94654df690318df7b9b49e5a3ef88.tar.xz | |
block/rnbd-clt: Support polling mode for IO latency optimization
RNBD can make double-queues for irq-mode and poll-mode.
For example, on 4-CPU system 8 request-queues are created,
4 for irq-mode and 4 for poll-mode.
If the IO has HIPRI flag, the block-layer will call .poll function
of RNBD. Then IO is sent to the poll-mode queue.
Add optional nr_poll_queues argument for map_devices interface.
To support polling of RNBD, RTRS client creates connections
for both of irq-mode and direct-poll-mode.
For example, on 4-CPU system it could've create 5 connections:
con[0] => user message (softirq cq)
con[1:4] => softirq cq
After this patch, it can create 9 connections:
con[0] => user message (softirq cq)
con[1:4] => softirq cq
con[5:8] => DIRECT-POLL cq
Cc: Leon Romanovsky <leonro@nvidia.com>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Acked-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Link: https://lore.kernel.org/r/20210419073722.15351-14-gi-oh.kim@ionos.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block/rnbd/rnbd-clt.h')
| -rw-r--r-- | drivers/block/rnbd/rnbd-clt.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/block/rnbd/rnbd-clt.h b/drivers/block/rnbd/rnbd-clt.h index 714d426b449b..451e7383738f 100644 --- a/drivers/block/rnbd/rnbd-clt.h +++ b/drivers/block/rnbd/rnbd-clt.h @@ -90,6 +90,7 @@ struct rnbd_clt_session { int queue_depth; u32 max_io_size; struct blk_mq_tag_set tag_set; + u32 nr_poll_queues; struct mutex lock; /* protects state and devs_list */ struct list_head devs_list; /* list of struct rnbd_clt_dev */ refcount_t refcount; @@ -118,6 +119,7 @@ struct rnbd_clt_dev { enum rnbd_clt_dev_state dev_state; char *pathname; enum rnbd_access_mode access_mode; + u32 nr_poll_queues; bool read_only; bool rotational; bool wc; @@ -147,7 +149,8 @@ struct rnbd_clt_dev *rnbd_clt_map_device(const char *sessname, struct rtrs_addr *paths, size_t path_cnt, u16 port_nr, const char *pathname, - enum rnbd_access_mode access_mode); + enum rnbd_access_mode access_mode, + u32 nr_poll_queues); int rnbd_clt_unmap_device(struct rnbd_clt_dev *dev, bool force, const struct attribute *sysfs_self); |