Commit c0219c49 authored by Chuck Lever's avatar Chuck Lever
Browse files

SUNRPC: Merge svc_do_enqueue_xprt() into svc_enqueue_xprt() 



Neil says:
"These functions were separated in commit 0971374e ("SUNRPC:
Reduce contention in svc_xprt_enqueue()") so that the XPT_BUSY check
happened before taking any spinlocks.

We have since moved or removed the spinlocks so the extra test is
fairly pointless."

I've made this a separate patch in case the XPT_BUSY change has
unexpected consequences and needs to be reverted.

Suggested-by: default avatarNeil Brown <neilb@suse.de>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent a9ff2e99

net/sunrpc/svc_xprt.c

+10 −16
Original line number Diff line number Diff line
@@ -32,7 +32,6 @@ static int svc_deferred_recv(struct svc_rqst *rqstp); 
static struct cache_deferred_req *svc_defer(struct cache_req *req);

static void svc_age_temp_xprts(struct timer_list *t);

static void svc_delete_xprt(struct svc_xprt *xprt);

static void svc_xprt_do_enqueue(struct svc_xprt *xprt);



/* apparently the "standard" is that clients close

 * idle connections after 5 minutes, servers after
@@ -267,12 +266,12 @@ void svc_xprt_received(struct svc_xprt *xprt) 
	}



	/* As soon as we clear busy, the xprt could be closed and

	 * 'put', so we need a reference to call svc_xprt_do_enqueue with:

	 * 'put', so we need a reference to call svc_xprt_enqueue with:

	 */

	svc_xprt_get(xprt);

	smp_mb__before_atomic();

	clear_bit(XPT_BUSY, &xprt->xpt_flags);

	svc_xprt_do_enqueue(xprt);

	svc_xprt_enqueue(xprt);

	svc_xprt_put(xprt);

}

EXPORT_SYMBOL_GPL(svc_xprt_received);
@@ -412,6 +411,8 @@ static bool svc_xprt_ready(struct svc_xprt *xprt) 
	smp_rmb();

	xpt_flags = READ_ONCE(xprt->xpt_flags);



	if (xpt_flags & BIT(XPT_BUSY))

		return false;

	if (xpt_flags & (BIT(XPT_CONN) | BIT(XPT_CLOSE)))

		return true;

	if (xpt_flags & (BIT(XPT_DATA) | BIT(XPT_DEFERRED))) {
@@ -424,7 +425,12 @@ static bool svc_xprt_ready(struct svc_xprt *xprt) 
	return false;

}



static void svc_xprt_do_enqueue(struct svc_xprt *xprt)

/**

 * svc_xprt_enqueue - Queue a transport on an idle nfsd thread

 * @xprt: transport with data pending

 *

 */

void svc_xprt_enqueue(struct svc_xprt *xprt)

{

	struct svc_pool *pool;

	struct svc_rqst	*rqstp = NULL;
@@ -468,18 +474,6 @@ static void svc_xprt_do_enqueue(struct svc_xprt *xprt) 
	put_cpu();

	trace_svc_xprt_enqueue(xprt, rqstp);

}



/*

 * Queue up a transport with data pending. If there are idle nfsd

 * processes, wake 'em up.

 *

 */

void svc_xprt_enqueue(struct svc_xprt *xprt)

{

	if (test_bit(XPT_BUSY, &xprt->xpt_flags))

		return;

	svc_xprt_do_enqueue(xprt);

}

EXPORT_SYMBOL_GPL(svc_xprt_enqueue);



/*