diff options
| author | Sagi Grimberg <sagi@grimberg.me> | 2018-11-20 01:11:12 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-12-08 08:26:57 +0300 |
| commit | e6a622fd6d66b83779357e3400f487fc159a7d83 (patch) | |
| tree | 23c128b4f918466bea9dc3c7a2669ea9916ea849 /drivers/nvme/target/fabrics-cmd.c | |
| parent | 6e2e312ea7ff73acfafaa5c9851e151e9483c761 (diff) | |
| download | linux-e6a622fd6d66b83779357e3400f487fc159a7d83.tar.xz | |
nvmet: support fabrics sq flow control
Technical proposal 8005 "fabrics SQ flow control" introduces a mode
where a host and controller agree to omit sq_head pointer updates
when sending nvme completions.
In case the host indicated desire to operate in this mode (connect attribute)
the controller will return back a connect completion with sq_head value
of 0xffff as indication that it will omit sq_head pointer updates.
This mode saves us an atomic update in the I/O path.
Reviewed-by: Hannes Reinecke <hare@suse.com>
[hch: suggested better implementation]
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/nvme/target/fabrics-cmd.c')
| -rw-r--r-- | drivers/nvme/target/fabrics-cmd.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/nvme/target/fabrics-cmd.c b/drivers/nvme/target/fabrics-cmd.c index d84ae004cb85..328ae46d8344 100644 --- a/drivers/nvme/target/fabrics-cmd.c +++ b/drivers/nvme/target/fabrics-cmd.c @@ -115,6 +115,12 @@ static u16 nvmet_install_queue(struct nvmet_ctrl *ctrl, struct nvmet_req *req) /* note: convert queue size from 0's-based value to 1's-based value */ nvmet_cq_setup(ctrl, req->cq, qid, sqsize + 1); nvmet_sq_setup(ctrl, req->sq, qid, sqsize + 1); + + if (c->cattr & NVME_CONNECT_DISABLE_SQFLOW) { + req->sq->sqhd_disabled = true; + req->rsp->sq_head = cpu_to_le16(0xffff); + } + return 0; } |