[PATCH RFC 2/3] rdma core: Add rdma_rw_mr_payload()
DORMANTno replies
From: Chuck Lever <hidden>
Date: 2017-08-01 21:07:07
Subsystem:
infiniband subsystem, the rest · Maintainers:
Jason Gunthorpe, Leon Romanovsky, Linus Torvalds
Possibly related (same subject, not in this thread)
- 2017-08-18 · Re: [PATCH RFC 2/3] rdma core: Add rdma_rw_mr_payload() · Doug Ledford <hidden>
The amount of payload per MR depends on device capabilities and the memory registration mode in use. The new rdma_rw API hides both, making it difficult for ULPs to determine how large their transport send queues need to be. Expose the MR payload information via a new API. Signed-off-by: Chuck Lever <redacted> --- drivers/infiniband/core/rw.c | 24 ++++++++++++++++++++++++ include/rdma/rw.h | 2 ++ 2 files changed, 26 insertions(+)
diff --git a/drivers/infiniband/core/rw.c b/drivers/infiniband/core/rw.c
index dbfd854..6ca607e 100644
--- a/drivers/infiniband/core/rw.c
+++ b/drivers/infiniband/core/rw.c@@ -643,6 +643,30 @@ void rdma_rw_ctx_destroy_signature(struct rdma_rw_ctx *ctx, struct ib_qp *qp, } EXPORT_SYMBOL(rdma_rw_ctx_destroy_signature); +/** + * rdma_rw_mr_factor - return number of MRs required for a payload + * @device: device handling the connection + * @port_num: port num to which the connection is bound + * @maxpages: maximum payload pages per rdma_rw_ctx + * + * Returns the number of MRs the device requires to move @maxpayload + * bytes. The returned value is used during transport creation to + * compute max_rdma_ctxts and the size of the transport's Send and + * Send Completion Queues. + */ +unsigned int rdma_rw_mr_factor(struct ib_device *device, u8 port_num, + unsigned int maxpages) +{ + unsigned int mr_pages; + + if (rdma_rw_can_use_mr(device, port_num)) + mr_pages = rdma_rw_fr_page_list_len(device); + else + mr_pages = device->attrs.max_sge_rd; + return DIV_ROUND_UP(maxpages, mr_pages); +} +EXPORT_SYMBOL(rdma_rw_mr_factor); + void rdma_rw_init_qp(struct ib_device *dev, struct ib_qp_init_attr *attr) { u32 factor;
diff --git a/include/rdma/rw.h b/include/rdma/rw.h
index 377d865..a3cbbc7 100644
--- a/include/rdma/rw.h
+++ b/include/rdma/rw.h@@ -81,6 +81,8 @@ struct ib_send_wr *rdma_rw_ctx_wrs(struct rdma_rw_ctx *ctx, struct ib_qp *qp, int rdma_rw_ctx_post(struct rdma_rw_ctx *ctx, struct ib_qp *qp, u8 port_num, struct ib_cqe *cqe, struct ib_send_wr *chain_wr); +unsigned int rdma_rw_mr_factor(struct ib_device *device, u8 port_num, + unsigned int maxpages); void rdma_rw_init_qp(struct ib_device *dev, struct ib_qp_init_attr *attr); int rdma_rw_init_mrs(struct ib_qp *qp, struct ib_qp_init_attr *attr); void rdma_rw_cleanup_mrs(struct ib_qp *qp); --
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