Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 87407673 authored by Tom Tucker's avatar Tom Tucker
Browse files

svcrdma: Use standard Linux lists for context cache 



Replace the one-off linked list implementation used to implement the
context cache with the standard Linux list_head lists. Add a context
counter to catch resource leaks. A WARN_ON will be added later to
ensure that we've freed all contexts.

Signed-off-by: default avatarTom Tucker <tom@opengridcomputing.com>
parent 02e7452d

include/linux/sunrpc/svc_rdma.h

+3 −2
Original line number Diff line number Diff line
@@ -72,7 +72,7 @@ extern atomic_t rdma_stat_sq_prod; 
 */

struct svc_rdma_op_ctxt {

	struct svc_rdma_op_ctxt *read_hdr;

	struct svc_rdma_op_ctxt *next;

	struct list_head free_list;

	struct xdr_buf arg;

	struct list_head dto_q;

	enum ib_wr_opcode wr_op;
@@ -104,7 +104,8 @@ struct svcxprt_rdma { 


	struct ib_pd         *sc_pd;



	struct svc_rdma_op_ctxt  *sc_ctxt_head;

	atomic_t	     sc_ctxt_used;

	struct list_head     sc_ctxt_free;

	int		     sc_ctxt_cnt;

	int		     sc_ctxt_bump;

	int		     sc_ctxt_max;

net/sunrpc/xprtrdma/svc_rdma_transport.c

+26 −21
Original line number Diff line number Diff line
@@ -103,8 +103,8 @@ static int rdma_bump_context_cache(struct svcxprt_rdma *xprt) 
		spin_lock_bh(&xprt->sc_ctxt_lock);

		if (ctxt) {

			at_least_one = 1;

			ctxt->next = xprt->sc_ctxt_head;

			xprt->sc_ctxt_head = ctxt;

			INIT_LIST_HEAD(&ctxt->free_list);

			list_add(&ctxt->free_list, &xprt->sc_ctxt_free);

		} else {

			/* kmalloc failed...give up for now */

			xprt->sc_ctxt_cnt--;
@@ -123,7 +123,7 @@ struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *xprt) 


	while (1) {

		spin_lock_bh(&xprt->sc_ctxt_lock);

		if (unlikely(xprt->sc_ctxt_head == NULL)) {

		if (unlikely(list_empty(&xprt->sc_ctxt_free))) {

			/* Try to bump my cache. */

			spin_unlock_bh(&xprt->sc_ctxt_lock);
@@ -136,12 +136,15 @@ struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *xprt) 
			schedule_timeout_uninterruptible(msecs_to_jiffies(500));

			continue;

		}

		ctxt = xprt->sc_ctxt_head;

		xprt->sc_ctxt_head = ctxt->next;

		ctxt = list_entry(xprt->sc_ctxt_free.next,

				  struct svc_rdma_op_ctxt,

				  free_list);

		list_del_init(&ctxt->free_list);

		spin_unlock_bh(&xprt->sc_ctxt_lock);

		ctxt->xprt = xprt;

		INIT_LIST_HEAD(&ctxt->dto_q);

		ctxt->count = 0;

		atomic_inc(&xprt->sc_ctxt_used);

		break;

	}

	return ctxt;
@@ -163,10 +166,11 @@ void svc_rdma_put_context(struct svc_rdma_op_ctxt *ctxt, int free_pages) 
				 ctxt->sge[i].addr,

				 ctxt->sge[i].length,

				 ctxt->direction);



	spin_lock_bh(&xprt->sc_ctxt_lock);

	ctxt->next = xprt->sc_ctxt_head;

	xprt->sc_ctxt_head = ctxt;

	list_add(&ctxt->free_list, &xprt->sc_ctxt_free);

	spin_unlock_bh(&xprt->sc_ctxt_lock);

	atomic_dec(&xprt->sc_ctxt_used);

}



/* ib_cq event handler */
@@ -412,28 +416,29 @@ static void create_context_cache(struct svcxprt_rdma *xprt, 
	xprt->sc_ctxt_max = ctxt_max;

	xprt->sc_ctxt_bump = ctxt_bump;

	xprt->sc_ctxt_cnt = 0;

	xprt->sc_ctxt_head = NULL;

	atomic_set(&xprt->sc_ctxt_used, 0);



	INIT_LIST_HEAD(&xprt->sc_ctxt_free);

	for (i = 0; i < ctxt_count; i++) {

		ctxt = kmalloc(sizeof(*ctxt), GFP_KERNEL);

		if (ctxt) {

			ctxt->next = xprt->sc_ctxt_head;

			xprt->sc_ctxt_head = ctxt;

			INIT_LIST_HEAD(&ctxt->free_list);

			list_add(&ctxt->free_list, &xprt->sc_ctxt_free);

			xprt->sc_ctxt_cnt++;

		}

	}

}



static void destroy_context_cache(struct svc_rdma_op_ctxt *ctxt)

static void destroy_context_cache(struct svcxprt_rdma *xprt)

{

	struct svc_rdma_op_ctxt *next;

	if (!ctxt)

		return;



	do {

		next = ctxt->next;

	while (!list_empty(&xprt->sc_ctxt_free)) {

		struct svc_rdma_op_ctxt *ctxt;

		ctxt = list_entry(xprt->sc_ctxt_free.next,

				  struct svc_rdma_op_ctxt,

				  free_list);

		list_del_init(&ctxt->free_list);

		kfree(ctxt);

		ctxt = next;

	} while (next);

	}

}



static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *serv,
@@ -470,7 +475,7 @@ static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *serv, 
				     reqs +

				     cma_xprt->sc_sq_depth +

				     RPCRDMA_MAX_THREADS + 1); /* max */

		if (!cma_xprt->sc_ctxt_head) {

		if (list_empty(&cma_xprt->sc_ctxt_free)) {

			kfree(cma_xprt);

			return NULL;

		}
@@ -976,7 +981,7 @@ static void svc_rdma_free(struct svc_xprt *xprt) 
	if (rdma->sc_pd && !IS_ERR(rdma->sc_pd))

		ib_dealloc_pd(rdma->sc_pd);



	destroy_context_cache(rdma->sc_ctxt_head);

	destroy_context_cache(rdma);

	kfree(rdma);

}