| Message ID | 20171006214243.11296-3-bart.vanassche@wdc.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
On Fri, Oct 06, 2017 at 02:42:38PM -0700, Bart Van Assche wrote:
> This patch is a micro-optimization for the hot path.
How much does it buy you on what workload?
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On Sun, 2017-10-08 at 02:01 -0700, Christoph Hellwig wrote: > On Fri, Oct 06, 2017 at 02:42:38PM -0700, Bart Van Assche wrote: > > This patch is a micro-optimization for the hot path. > > How much does it buy you on what workload? Hello Christoph, Because I assume that the improvement realized by this patch will be smaller than the measurement error I have not yet tried to measure how much this patch impacts performance. Yet I think this patch is beneficial because it touches code in the hot path and because it reduces the number of pointer indirections in that code path. Bart.
diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c index 76370e39857d..6cf95ad870cc 100644 --- a/drivers/infiniband/ulp/srpt/ib_srpt.c +++ b/drivers/infiniband/ulp/srpt/ib_srpt.c @@ -766,7 +766,7 @@ static int srpt_post_recv(struct srpt_device *sdev, BUG_ON(!sdev); list.addr = ioctx->ioctx.dma; list.length = srp_max_req_size; - list.lkey = sdev->pd->local_dma_lkey; + list.lkey = sdev->lkey; ioctx->ioctx.cqe.done = srpt_recv_done; wr.wr_cqe = &ioctx->ioctx.cqe; @@ -2343,7 +2343,7 @@ static void srpt_queue_response(struct se_cmd *cmd) sge.addr = ioctx->ioctx.dma; sge.length = resp_len; - sge.lkey = sdev->pd->local_dma_lkey; + sge.lkey = sdev->lkey; ioctx->ioctx.cqe.done = srpt_send_done; send_wr.next = NULL; @@ -2491,6 +2491,8 @@ static void srpt_add_one(struct ib_device *device) if (IS_ERR(sdev->pd)) goto free_dev; + sdev->lkey = sdev->pd->local_dma_lkey; + sdev->srq_size = min(srpt_srq_size, sdev->device->attrs.max_srq_wr); srq_attr.event_handler = srpt_srq_event; diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.h b/drivers/infiniband/ulp/srpt/ib_srpt.h index 1b817e51b84b..976e924d7400 100644 --- a/drivers/infiniband/ulp/srpt/ib_srpt.h +++ b/drivers/infiniband/ulp/srpt/ib_srpt.h @@ -343,7 +343,7 @@ struct srpt_port { * struct srpt_device - Information associated by SRPT with a single HCA. * @device: Backpointer to the struct ib_device managed by the IB core. * @pd: IB protection domain. - * @mr: L_Key (local key) with write access to all local memory. + * @lkey: L_Key (local key) with write access to all local memory. * @srq: Per-HCA SRQ (shared receive queue). * @cm_id: Connection identifier. * @srq_size: SRQ size. @@ -358,6 +358,7 @@ struct srpt_port { struct srpt_device { struct ib_device *device; struct ib_pd *pd; + u32 lkey; struct ib_srq *srq; struct ib_cm_id *cm_id; int srq_size;
This patch is a micro-optimization for the hot path. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> --- drivers/infiniband/ulp/srpt/ib_srpt.c | 6 ++++-- drivers/infiniband/ulp/srpt/ib_srpt.h | 3 ++- 2 files changed, 6 insertions(+), 3 deletions(-)