xprtrdma: Pre-allocate backward rpc_rqst and send/receive buffers (f531a5db) · Commits · 戴 / test

net/sunrpc/xprtrdma/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -5,3 +5,4 @@ rpcrdma-y := transport.o rpc_rdma.o verbs.o \
		svc_rdma.o svc_rdma_transport.o \
		svc_rdma_marshal.o svc_rdma_sendto.o svc_rdma_recvfrom.o \
		module.o
		rpcrdma-$(CONFIG_SUNRPC_BACKCHANNEL) += backchannel.o

net/sunrpc/xprtrdma/backchannel.c

0 → 100644

+206 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (c) 2015 Oracle. All rights reserved.
		*
		* Support for backward direction RPCs on RPC/RDMA.
		*/

		#include <linux/module.h>

		#include "xprt_rdma.h"

		#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
		# define RPCDBG_FACILITY RPCDBG_TRANS
		#endif

		static void rpcrdma_bc_free_rqst(struct rpcrdma_xprt *r_xprt,
		struct rpc_rqst *rqst)
		{
		struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
		struct rpcrdma_req *req = rpcr_to_rdmar(rqst);

		spin_lock(&buf->rb_reqslock);
		list_del(&req->rl_all);
		spin_unlock(&buf->rb_reqslock);

		rpcrdma_destroy_req(&r_xprt->rx_ia, req);

		kfree(rqst);
		}

		static int rpcrdma_bc_setup_rqst(struct rpcrdma_xprt *r_xprt,
		struct rpc_rqst *rqst)
		{
		struct rpcrdma_ia *ia = &r_xprt->rx_ia;
		struct rpcrdma_regbuf *rb;
		struct rpcrdma_req *req;
		struct xdr_buf *buf;
		size_t size;

		req = rpcrdma_create_req(r_xprt);
		if (!req)
		return -ENOMEM;
		req->rl_backchannel = true;

		size = RPCRDMA_INLINE_WRITE_THRESHOLD(rqst);
		rb = rpcrdma_alloc_regbuf(ia, size, GFP_KERNEL);
		if (IS_ERR(rb))
		goto out_fail;
		req->rl_rdmabuf = rb;

		size += RPCRDMA_INLINE_READ_THRESHOLD(rqst);
		rb = rpcrdma_alloc_regbuf(ia, size, GFP_KERNEL);
		if (IS_ERR(rb))
		goto out_fail;
		rb->rg_owner = req;
		req->rl_sendbuf = rb;
		/* so that rpcr_to_rdmar works when receiving a request */
		rqst->rq_buffer = (void *)req->rl_sendbuf->rg_base;

		buf = &rqst->rq_snd_buf;
		buf->head[0].iov_base = rqst->rq_buffer;
		buf->head[0].iov_len = 0;
		buf->tail[0].iov_base = NULL;
		buf->tail[0].iov_len = 0;
		buf->page_len = 0;
		buf->len = 0;
		buf->buflen = size;

		return 0;

		out_fail:
		rpcrdma_bc_free_rqst(r_xprt, rqst);
		return -ENOMEM;
		}

		/* Allocate and add receive buffers to the rpcrdma_buffer's
		* existing list of rep's. These are released when the
		* transport is destroyed.
		*/
		static int rpcrdma_bc_setup_reps(struct rpcrdma_xprt *r_xprt,
		unsigned int count)
		{
		struct rpcrdma_buffer *buffers = &r_xprt->rx_buf;
		struct rpcrdma_rep *rep;
		unsigned long flags;
		int rc = 0;

		while (count--) {
		rep = rpcrdma_create_rep(r_xprt);
		if (IS_ERR(rep)) {
		pr_err("RPC: %s: reply buffer alloc failed\n",
		__func__);
		rc = PTR_ERR(rep);
		break;
		}

		spin_lock_irqsave(&buffers->rb_lock, flags);
		list_add(&rep->rr_list, &buffers->rb_recv_bufs);
		spin_unlock_irqrestore(&buffers->rb_lock, flags);
		}

		return rc;
		}

		/**
		* xprt_rdma_bc_setup - Pre-allocate resources for handling backchannel requests
		* @xprt: transport associated with these backchannel resources
		* @reqs: number of concurrent incoming requests to expect
		*
		* Returns 0 on success; otherwise a negative errno
		*/
		int xprt_rdma_bc_setup(struct rpc_xprt *xprt, unsigned int reqs)
		{
		struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
		struct rpcrdma_buffer *buffer = &r_xprt->rx_buf;
		struct rpc_rqst *rqst;
		unsigned int i;
		int rc;

		/* The backchannel reply path returns each rpc_rqst to the
		* bc_pa_list _after_ the reply is sent. If the server is
		* faster than the client, it can send another backward
		* direction request before the rpc_rqst is returned to the
		* list. The client rejects the request in this case.
		*
		* Twice as many rpc_rqsts are prepared to ensure there is
		* always an rpc_rqst available as soon as a reply is sent.
		*/
		for (i = 0; i < (reqs << 1); i++) {
		rqst = kzalloc(sizeof(*rqst), GFP_KERNEL);
		if (!rqst) {
		pr_err("RPC: %s: Failed to create bc rpc_rqst\n",
		__func__);
		goto out_free;
		}

		rqst->rq_xprt = &r_xprt->rx_xprt;
		INIT_LIST_HEAD(&rqst->rq_list);
		INIT_LIST_HEAD(&rqst->rq_bc_list);

		if (rpcrdma_bc_setup_rqst(r_xprt, rqst))
		goto out_free;

		spin_lock_bh(&xprt->bc_pa_lock);
		list_add(&rqst->rq_bc_pa_list, &xprt->bc_pa_list);
		spin_unlock_bh(&xprt->bc_pa_lock);
		}

		rc = rpcrdma_bc_setup_reps(r_xprt, reqs);
		if (rc)
		goto out_free;

		rc = rpcrdma_ep_post_extra_recv(r_xprt, reqs);
		if (rc)
		goto out_free;

		buffer->rb_bc_srv_max_requests = reqs;
		request_module("svcrdma");

		return 0;

		out_free:
		xprt_rdma_bc_destroy(xprt, reqs);

		pr_err("RPC: %s: setup backchannel transport failed\n", __func__);
		return -ENOMEM;
		}

		/**
		* xprt_rdma_bc_destroy - Release resources for handling backchannel requests
		* @xprt: transport associated with these backchannel resources
		* @reqs: number of incoming requests to destroy; ignored
		*/
		void xprt_rdma_bc_destroy(struct rpc_xprt *xprt, unsigned int reqs)
		{
		struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
		struct rpc_rqst rqst, tmp;

		spin_lock_bh(&xprt->bc_pa_lock);
		list_for_each_entry_safe(rqst, tmp, &xprt->bc_pa_list, rq_bc_pa_list) {
		list_del(&rqst->rq_bc_pa_list);
		spin_unlock_bh(&xprt->bc_pa_lock);

		rpcrdma_bc_free_rqst(r_xprt, rqst);

		spin_lock_bh(&xprt->bc_pa_lock);
		}
		spin_unlock_bh(&xprt->bc_pa_lock);
		}

		/**
		* xprt_rdma_bc_free_rqst - Release a backchannel rqst
		* @rqst: request to release
		*/
		void xprt_rdma_bc_free_rqst(struct rpc_rqst *rqst)
		{
		struct rpc_xprt *xprt = rqst->rq_xprt;

		smp_mb__before_atomic();
		WARN_ON_ONCE(!test_bit(RPC_BC_PA_IN_USE, &rqst->rq_bc_pa_state));
		clear_bit(RPC_BC_PA_IN_USE, &rqst->rq_bc_pa_state);
		smp_mb__after_atomic();

		spin_lock_bh(&xprt->bc_pa_lock);
		list_add_tail(&rqst->rq_bc_pa_list, &xprt->bc_pa_list);
		spin_unlock_bh(&xprt->bc_pa_lock);
		}

net/sunrpc/xprtrdma/transport.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -705,7 +705,12 @@ static struct rpc_xprt_ops xprt_rdma_procs = {
		.print_stats = xprt_rdma_print_stats,
		.enable_swap = xprt_rdma_enable_swap,
		.disable_swap = xprt_rdma_disable_swap,
		.inject_disconnect = xprt_rdma_inject_disconnect
		.inject_disconnect = xprt_rdma_inject_disconnect,
		#if defined(CONFIG_SUNRPC_BACKCHANNEL)
		.bc_setup = xprt_rdma_bc_setup,
		.bc_free_rqst = xprt_rdma_bc_free_rqst,
		.bc_destroy = xprt_rdma_bc_destroy,
		#endif
		};

		static struct xprt_class xprt_rdma = {

net/sunrpc/xprtrdma/verbs.c

+76 −11

Original line number	Diff line number	Diff line
		@@ -831,7 +831,21 @@ retry:
		}
		rc = ep->rep_connected;
		} else {
		struct rpcrdma_xprt *r_xprt;
		unsigned int extras;

		dprintk("RPC: %s: connected\n", __func__);

		r_xprt = container_of(ia, struct rpcrdma_xprt, rx_ia);
		extras = r_xprt->rx_buf.rb_bc_srv_max_requests;

		if (extras) {
		rc = rpcrdma_ep_post_extra_recv(r_xprt, extras);
		if (rc)
		pr_warn("%s: rpcrdma_ep_post_extra_recv: %i\n",
		__func__, rc);
		rc = 0;
		}
		}

		out:
		@@ -868,20 +882,25 @@ rpcrdma_ep_disconnect(struct rpcrdma_ep ep, struct rpcrdma_ia ia)
		}
		}

		static struct rpcrdma_req *
		struct rpcrdma_req *
		rpcrdma_create_req(struct rpcrdma_xprt *r_xprt)
		{
		struct rpcrdma_buffer *buffer = &r_xprt->rx_buf;
		struct rpcrdma_req *req;

		req = kzalloc(sizeof(*req), GFP_KERNEL);
		if (req == NULL)
		return ERR_PTR(-ENOMEM);

		INIT_LIST_HEAD(&req->rl_free);
		spin_lock(&buffer->rb_reqslock);
		list_add(&req->rl_all, &buffer->rb_allreqs);
		spin_unlock(&buffer->rb_reqslock);
		req->rl_buffer = &r_xprt->rx_buf;
		return req;
		}

		static struct rpcrdma_rep *
		struct rpcrdma_rep *
		rpcrdma_create_rep(struct rpcrdma_xprt *r_xprt)
		{
		struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
		@@ -920,6 +939,7 @@ rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
		int i, rc;

		buf->rb_max_requests = r_xprt->rx_data.max_requests;
		buf->rb_bc_srv_max_requests = 0;
		spin_lock_init(&buf->rb_lock);

		rc = ia->ri_ops->ro_init(r_xprt);
		@@ -927,6 +947,8 @@ rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
		goto out;

		INIT_LIST_HEAD(&buf->rb_send_bufs);
		INIT_LIST_HEAD(&buf->rb_allreqs);
		spin_lock_init(&buf->rb_reqslock);
		for (i = 0; i < buf->rb_max_requests; i++) {
		struct rpcrdma_req *req;

		@@ -937,6 +959,7 @@ rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
		rc = PTR_ERR(req);
		goto out;
		}
		req->rl_backchannel = false;
		list_add(&req->rl_free, &buf->rb_send_bufs);
		}

		@@ -985,19 +1008,13 @@ rpcrdma_buffer_get_rep_locked(struct rpcrdma_buffer *buf)
		static void
		rpcrdma_destroy_rep(struct rpcrdma_ia ia, struct rpcrdma_rep rep)
		{
		if (!rep)
		return;

		rpcrdma_free_regbuf(ia, rep->rr_rdmabuf);
		kfree(rep);
		}

		static void
		void
		rpcrdma_destroy_req(struct rpcrdma_ia ia, struct rpcrdma_req req)
		{
		if (!req)
		return;

		rpcrdma_free_regbuf(ia, req->rl_sendbuf);
		rpcrdma_free_regbuf(ia, req->rl_rdmabuf);
		kfree(req);
		@@ -1015,12 +1032,19 @@ rpcrdma_buffer_destroy(struct rpcrdma_buffer *buf)
		rpcrdma_destroy_rep(ia, rep);
		}

		while (!list_empty(&buf->rb_send_bufs)) {
		spin_lock(&buf->rb_reqslock);
		while (!list_empty(&buf->rb_allreqs)) {
		struct rpcrdma_req *req;

		req = rpcrdma_buffer_get_req_locked(buf);
		req = list_first_entry(&buf->rb_allreqs,
		struct rpcrdma_req, rl_all);
		list_del(&req->rl_all);

		spin_unlock(&buf->rb_reqslock);
		rpcrdma_destroy_req(ia, req);
		spin_lock(&buf->rb_reqslock);
		}
		spin_unlock(&buf->rb_reqslock);

		ia->ri_ops->ro_destroy(buf);
		}
		@@ -1288,6 +1312,47 @@ rpcrdma_ep_post_recv(struct rpcrdma_ia *ia,
		return rc;
		}

		/**
		* rpcrdma_ep_post_extra_recv - Post buffers for incoming backchannel requests
		* @r_xprt: transport associated with these backchannel resources
		* @min_reqs: minimum number of incoming requests expected
		*
		* Returns zero if all requested buffers were posted, or a negative errno.
		*/
		int
		rpcrdma_ep_post_extra_recv(struct rpcrdma_xprt *r_xprt, unsigned int count)
		{
		struct rpcrdma_buffer *buffers = &r_xprt->rx_buf;
		struct rpcrdma_ia *ia = &r_xprt->rx_ia;
		struct rpcrdma_ep *ep = &r_xprt->rx_ep;
		struct rpcrdma_rep *rep;
		unsigned long flags;
		int rc;

		while (count--) {
		spin_lock_irqsave(&buffers->rb_lock, flags);
		if (list_empty(&buffers->rb_recv_bufs))
		goto out_reqbuf;
		rep = rpcrdma_buffer_get_rep_locked(buffers);
		spin_unlock_irqrestore(&buffers->rb_lock, flags);

		rc = rpcrdma_ep_post_recv(ia, ep, rep);
		if (rc)
		goto out_rc;
		}

		return 0;

		out_reqbuf:
		spin_unlock_irqrestore(&buffers->rb_lock, flags);
		pr_warn("%s: no extra receive buffers\n", __func__);
		return -ENOMEM;

		out_rc:
		rpcrdma_recv_buffer_put(rep);
		return rc;
		}

		/* How many chunk list items fit within our inline buffers?
		*/
		unsigned int

net/sunrpc/xprtrdma/xprt_rdma.h

+20 −0

Original line number	Diff line number	Diff line
		@@ -263,6 +263,9 @@ struct rpcrdma_req {
		struct rpcrdma_regbuf *rl_rdmabuf;
		struct rpcrdma_regbuf *rl_sendbuf;
		struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS];

		struct list_head rl_all;
		bool rl_backchannel;
		};

		static inline struct rpcrdma_req *
		@@ -291,6 +294,10 @@ struct rpcrdma_buffer {
		struct list_head rb_send_bufs;
		struct list_head rb_recv_bufs;
		u32 rb_max_requests;

		u32 rb_bc_srv_max_requests;
		spinlock_t rb_reqslock; /* protect rb_allreqs */
		struct list_head rb_allreqs;
		};
		#define rdmab_to_ia(b) (&container_of((b), struct rpcrdma_xprt, rx_buf)->rx_ia)

		@@ -411,6 +418,9 @@ int rpcrdma_ep_post_recv(struct rpcrdma_ia , struct rpcrdma_ep ,
		/*
		* Buffer calls - xprtrdma/verbs.c
		*/
		struct rpcrdma_req rpcrdma_create_req(struct rpcrdma_xprt );
		struct rpcrdma_rep rpcrdma_create_rep(struct rpcrdma_xprt );
		void rpcrdma_destroy_req(struct rpcrdma_ia , struct rpcrdma_req );
		int rpcrdma_buffer_create(struct rpcrdma_xprt *);
		void rpcrdma_buffer_destroy(struct rpcrdma_buffer *);

		@@ -427,6 +437,7 @@ void rpcrdma_free_regbuf(struct rpcrdma_ia *,
		struct rpcrdma_regbuf *);

		unsigned int rpcrdma_max_segments(struct rpcrdma_xprt *);
		int rpcrdma_ep_post_extra_recv(struct rpcrdma_xprt *, unsigned int);

		int frwr_alloc_recovery_wq(void);
		void frwr_destroy_recovery_wq(void);
		@@ -494,6 +505,15 @@ int rpcrdma_marshal_req(struct rpc_rqst *);
		int xprt_rdma_init(void);
		void xprt_rdma_cleanup(void);

		/* Backchannel calls - xprtrdma/backchannel.c
		*/
		#if defined(CONFIG_SUNRPC_BACKCHANNEL)
		int xprt_rdma_bc_setup(struct rpc_xprt *, unsigned int);
		int rpcrdma_bc_post_recv(struct rpcrdma_xprt *, unsigned int);
		void xprt_rdma_bc_free_rqst(struct rpc_rqst *);
		void xprt_rdma_bc_destroy(struct rpc_xprt *, unsigned int);
		#endif /* CONFIG_SUNRPC_BACKCHANNEL */

		/* Temporary NFS request map cache. Created in svc_rdma.c */
		extern struct kmem_cache *svc_rdma_map_cachep;
		/* WR context cache. Created in svc_rdma.c */

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