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Commit ff699ea8 authored by Chuck Lever's avatar Chuck Lever Committed by Anna Schumaker
Browse files

SUNRPC: Make num_reqs a non-atomic integer 



If recording xprt->stat.max_slots is moved into xprt_alloc_slot,
then xprt->num_reqs is never manipulated outside
xprt->reserve_lock. There's no longer a need for xprt->num_reqs to
be atomic.

Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent 78215759

include/linux/sunrpc/xprt.h

+1 −1
Original line number Diff line number Diff line
@@ -197,7 +197,7 @@ struct rpc_xprt { 
	struct list_head	free;		/* free slots */

	unsigned int		max_reqs;	/* max number of slots */

	unsigned int		min_reqs;	/* min number of slots */

	atomic_t		num_reqs;	/* total slots */

	unsigned int		num_reqs;	/* total slots */

	unsigned long		state;		/* transport state */

	unsigned char		resvport   : 1; /* use a reserved port */

	atomic_t		swapper;	/* we're swapping over this

net/sunrpc/xprt.c

+9 −8
Original line number Diff line number Diff line
@@ -1009,7 +1009,7 @@ void xprt_transmit(struct rpc_task *task) 
	struct rpc_rqst	*req = task->tk_rqstp;

	struct rpc_xprt	*xprt = req->rq_xprt;

	unsigned int connect_cookie;

	int status, numreqs;

	int status;



	dprintk("RPC: %5u xprt_transmit(%u)\n", task->tk_pid, req->rq_slen);
@@ -1047,9 +1047,6 @@ void xprt_transmit(struct rpc_task *task) 


	xprt->ops->set_retrans_timeout(task);



	numreqs = atomic_read(&xprt->num_reqs);

	if (numreqs > xprt->stat.max_slots)

		xprt->stat.max_slots = numreqs;

	xprt->stat.sends++;

	xprt->stat.req_u += xprt->stat.sends - xprt->stat.recvs;

	xprt->stat.bklog_u += xprt->backlog.qlen;
@@ -1111,14 +1108,15 @@ static struct rpc_rqst *xprt_dynamic_alloc_slot(struct rpc_xprt *xprt) 
{

	struct rpc_rqst *req = ERR_PTR(-EAGAIN);



	if (!atomic_add_unless(&xprt->num_reqs, 1, xprt->max_reqs))

	if (xprt->num_reqs >= xprt->max_reqs)

		goto out;

	++xprt->num_reqs;

	spin_unlock(&xprt->reserve_lock);

	req = kzalloc(sizeof(struct rpc_rqst), GFP_NOFS);

	spin_lock(&xprt->reserve_lock);

	if (req != NULL)

		goto out;

	atomic_dec(&xprt->num_reqs);

	--xprt->num_reqs;

	req = ERR_PTR(-ENOMEM);

out:

	return req;
@@ -1126,7 +1124,8 @@ static struct rpc_rqst *xprt_dynamic_alloc_slot(struct rpc_xprt *xprt) 


static bool xprt_dynamic_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req)

{

	if (atomic_add_unless(&xprt->num_reqs, -1, xprt->min_reqs)) {

	if (xprt->num_reqs > xprt->min_reqs) {

		--xprt->num_reqs;

		kfree(req);

		return true;

	}
@@ -1162,6 +1161,8 @@ void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task) 
	spin_unlock(&xprt->reserve_lock);

	return;

out_init_req:

	xprt->stat.max_slots = max_t(unsigned int, xprt->stat.max_slots,

				     xprt->num_reqs);

	task->tk_status = 0;

	task->tk_rqstp = req;

	xprt_request_init(task, xprt);
@@ -1229,7 +1230,7 @@ struct rpc_xprt *xprt_alloc(struct net *net, size_t size, 
	else

		xprt->max_reqs = num_prealloc;

	xprt->min_reqs = num_prealloc;

	atomic_set(&xprt->num_reqs, num_prealloc);

	xprt->num_reqs = num_prealloc;



	return xprt;