Commit 4866073e authored by Chuck Lever's avatar Chuck Lever Committed by J. Bruce Fields
Browse files

svcrdma: Use llist for managing cache of recv_ctxts 



Use a wait-free mechanism for managing the svc_rdma_recv_ctxts free
list. Subsequently, sc_recv_lock can be eliminated.

Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent d6dfe43e

include/linux/sunrpc/svc_rdma.h

+3 −2
Original line number Diff line number Diff line
@@ -42,6 +42,7 @@ 


#ifndef SVC_RDMA_H

#define SVC_RDMA_H

#include <linux/llist.h>

#include <linux/sunrpc/xdr.h>

#include <linux/sunrpc/svcsock.h>

#include <linux/sunrpc/rpc_rdma.h>
@@ -107,8 +108,7 @@ struct svcxprt_rdma { 
	struct list_head     sc_read_complete_q;

	struct work_struct   sc_work;



	spinlock_t	     sc_recv_lock;

	struct list_head     sc_recv_ctxts;

	struct llist_head    sc_recv_ctxts;

};

/* sc_flags */

#define RDMAXPRT_CONN_PENDING	3
@@ -125,6 +125,7 @@ enum { 
#define RPCSVC_MAXPAYLOAD_RDMA	RPCSVC_MAXPAYLOAD



struct svc_rdma_recv_ctxt {

	struct llist_node	rc_node;

	struct list_head	rc_list;

	struct ib_recv_wr	rc_recv_wr;

	struct ib_cqe		rc_cqe;

net/sunrpc/xprtrdma/svc_rdma_recvfrom.c

+10 −14
Original line number Diff line number Diff line
@@ -172,9 +172,10 @@ static void svc_rdma_recv_ctxt_destroy(struct svcxprt_rdma *rdma, 
void svc_rdma_recv_ctxts_destroy(struct svcxprt_rdma *rdma)

{

	struct svc_rdma_recv_ctxt *ctxt;

	struct llist_node *node;



	while ((ctxt = svc_rdma_next_recv_ctxt(&rdma->sc_recv_ctxts))) {

		list_del(&ctxt->rc_list);

	while ((node = llist_del_first(&rdma->sc_recv_ctxts))) {

		ctxt = llist_entry(node, struct svc_rdma_recv_ctxt, rc_node);

		svc_rdma_recv_ctxt_destroy(rdma, ctxt);

	}

}
@@ -183,21 +184,18 @@ static struct svc_rdma_recv_ctxt * 
svc_rdma_recv_ctxt_get(struct svcxprt_rdma *rdma)

{

	struct svc_rdma_recv_ctxt *ctxt;

	struct llist_node *node;



	spin_lock(&rdma->sc_recv_lock);

	ctxt = svc_rdma_next_recv_ctxt(&rdma->sc_recv_ctxts);

	if (!ctxt)

	node = llist_del_first(&rdma->sc_recv_ctxts);

	if (!node)

		goto out_empty;

	list_del(&ctxt->rc_list);

	spin_unlock(&rdma->sc_recv_lock);

	ctxt = llist_entry(node, struct svc_rdma_recv_ctxt, rc_node);



out:

	ctxt->rc_page_count = 0;

	return ctxt;



out_empty:

	spin_unlock(&rdma->sc_recv_lock);



	ctxt = svc_rdma_recv_ctxt_alloc(rdma);

	if (!ctxt)

		return NULL;
@@ -218,11 +216,9 @@ void svc_rdma_recv_ctxt_put(struct svcxprt_rdma *rdma, 
	for (i = 0; i < ctxt->rc_page_count; i++)

		put_page(ctxt->rc_pages[i]);



	if (!ctxt->rc_temp) {

		spin_lock(&rdma->sc_recv_lock);

		list_add(&ctxt->rc_list, &rdma->sc_recv_ctxts);

		spin_unlock(&rdma->sc_recv_lock);

	} else

	if (!ctxt->rc_temp)

		llist_add(&ctxt->rc_node, &rdma->sc_recv_ctxts);

	else

		svc_rdma_recv_ctxt_destroy(rdma, ctxt);

}

net/sunrpc/xprtrdma/svc_rdma_transport.c

+1 −2
Original line number Diff line number Diff line
@@ -140,14 +140,13 @@ static struct svcxprt_rdma *svc_rdma_create_xprt(struct svc_serv *serv, 
	INIT_LIST_HEAD(&cma_xprt->sc_rq_dto_q);

	INIT_LIST_HEAD(&cma_xprt->sc_read_complete_q);

	INIT_LIST_HEAD(&cma_xprt->sc_send_ctxts);

	INIT_LIST_HEAD(&cma_xprt->sc_recv_ctxts);

	init_llist_head(&cma_xprt->sc_recv_ctxts);

	INIT_LIST_HEAD(&cma_xprt->sc_rw_ctxts);

	init_waitqueue_head(&cma_xprt->sc_send_wait);



	spin_lock_init(&cma_xprt->sc_lock);

	spin_lock_init(&cma_xprt->sc_rq_dto_lock);

	spin_lock_init(&cma_xprt->sc_send_lock);

	spin_lock_init(&cma_xprt->sc_recv_lock);

	spin_lock_init(&cma_xprt->sc_rw_ctxt_lock);



	/*

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