From 5ab8142839c714ed5ac9a9de1846ab71f87a3ed7 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Wed, 29 Jun 2016 13:54:25 -0400 Subject: xprtrdma: Chunk list encoders no longer share one rl_segments array Currently, all three chunk list encoders each use a portion of the one rl_segments array in rpcrdma_req. This is because the MWs for each chunk list were preserved in rl_segments so that ro_unmap could find and invalidate them after the RPC was complete. However, now that MWs are placed on a per-req linked list as they are registered, there is no longer any information in rpcrdma_mr_seg that is shared between ro_map and ro_unmap_{sync,safe}, and thus nothing in rl_segments needs to be preserved after rpcrdma_marshal_req is complete. Thus the rl_segments array can be used now just for the needs of each rpcrdma_convert_iovs call. Once each chunk list is encoded, the next chunk list encoder is free to re-use all of rl_segments. This means all three chunk lists in one RPC request can now each encode a full size data payload with no increase in the size of rl_segments. This is a key requirement for Kerberos support, since both the Call and Reply for a single RPC transaction are conveyed via Long messages (RDMA Read/Write). Both can be large. Signed-off-by: Chuck Lever Tested-by: Steve Wise Signed-off-by: Anna Schumaker --- net/sunrpc/xprtrdma/xprt_rdma.h | 36 ++++++++++++++++-------------------- 1 file changed, 16 insertions(+), 20 deletions(-) (limited to 'net/sunrpc/xprtrdma/xprt_rdma.h') diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h index f5d05110de9f..670fad57153a 100644 --- a/net/sunrpc/xprtrdma/xprt_rdma.h +++ b/net/sunrpc/xprtrdma/xprt_rdma.h @@ -171,23 +171,14 @@ rdmab_to_msg(struct rpcrdma_regbuf *rb) * o recv buffer (posted to provider) * o ib_sge (also donated to provider) * o status of reply (length, success or not) - * o bookkeeping state to get run by tasklet (list, etc) + * o bookkeeping state to get run by reply handler (list, etc) * - * These are allocated during initialization, per-transport instance; - * however, the tasklet execution list itself is global, as it should - * always be pretty short. + * These are allocated during initialization, per-transport instance. * * N of these are associated with a transport instance, and stored in * struct rpcrdma_buffer. N is the max number of outstanding requests. */ -#define RPCRDMA_MAX_DATA_SEGS ((1 * 1024 * 1024) / PAGE_SIZE) - -/* data segments + head/tail for Call + head/tail for Reply */ -#define RPCRDMA_MAX_SEGS (RPCRDMA_MAX_DATA_SEGS + 4) - -struct rpcrdma_buffer; - struct rpcrdma_rep { struct ib_cqe rr_cqe; unsigned int rr_len; @@ -267,13 +258,18 @@ struct rpcrdma_mw { * of iovs for send operations. The reason is that the iovs passed to * ib_post_{send,recv} must not be modified until the work request * completes. - * - * NOTES: - * o RPCRDMA_MAX_SEGS is the max number of addressible chunk elements we - * marshal. The number needed varies depending on the iov lists that - * are passed to us and the memory registration mode we are in. */ +/* Maximum number of page-sized "segments" per chunk list to be + * registered or invalidated. Must handle a Reply chunk: + */ +enum { + RPCRDMA_MAX_IOV_SEGS = 3, + RPCRDMA_MAX_DATA_SEGS = ((1 * 1024 * 1024) / PAGE_SIZE) + 1, + RPCRDMA_MAX_SEGS = RPCRDMA_MAX_DATA_SEGS + + RPCRDMA_MAX_IOV_SEGS, +}; + struct rpcrdma_mr_seg { /* chunk descriptors */ u32 mr_len; /* length of chunk or segment */ struct page *mr_page; /* owning page, if any */ @@ -282,10 +278,10 @@ struct rpcrdma_mr_seg { /* chunk descriptors */ #define RPCRDMA_MAX_IOVS (2) +struct rpcrdma_buffer; struct rpcrdma_req { struct list_head rl_free; unsigned int rl_niovs; - unsigned int rl_nchunks; unsigned int rl_connect_cookie; struct rpc_task *rl_task; struct rpcrdma_buffer *rl_buffer; @@ -293,13 +289,13 @@ struct rpcrdma_req { struct ib_sge rl_send_iov[RPCRDMA_MAX_IOVS]; struct rpcrdma_regbuf *rl_rdmabuf; struct rpcrdma_regbuf *rl_sendbuf; - struct list_head rl_registered; /* registered segments */ - struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS]; - struct rpcrdma_mr_seg *rl_nextseg; struct ib_cqe rl_cqe; struct list_head rl_all; bool rl_backchannel; + + struct list_head rl_registered; /* registered segments */ + struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS]; }; static inline struct rpcrdma_req * -- cgit v1.2.3