Commit 8954c5c2 authored by Chuck Lever's avatar Chuck Lever
Browse files

SUNRPC: Clean up request deferral tracepoints 



- Rename these so they are easy to enable and search for as a set
- Move the tracepoints to get a more accurate sense of control flow
- Tracepoints should not fire on xprt shutdown
- Display memory address in case data structure had been corrupted
- Abandon dprintk in these paths

I haven't ever gotten one of these tracepoints to trigger. I wonder
if we should simply remove them.

Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent 1eace0d1

include/trace/events/sunrpc.h

+8 −3
Original line number Diff line number Diff line
@@ -1406,27 +1406,32 @@ DECLARE_EVENT_CLASS(svc_deferred_event, 
	TP_ARGS(dr),



	TP_STRUCT__entry(

		__field(const void *, dr)

		__field(u32, xid)

		__string(addr, dr->xprt->xpt_remotebuf)

	),



	TP_fast_assign(

		__entry->dr = dr;

		__entry->xid = be32_to_cpu(*(__be32 *)(dr->args +

						       (dr->xprt_hlen>>2)));

		__assign_str(addr, dr->xprt->xpt_remotebuf);

	),



	TP_printk("addr=%s xid=0x%08x", __get_str(addr), __entry->xid)

	TP_printk("addr=%s dr=%p xid=0x%08x", __get_str(addr), __entry->dr,

		__entry->xid)

);



#define DEFINE_SVC_DEFERRED_EVENT(name) \

	DEFINE_EVENT(svc_deferred_event, svc_##name##_deferred, \

	DEFINE_EVENT(svc_deferred_event, svc_defer_##name, \

			TP_PROTO( \

				const struct svc_deferred_req *dr \

			), \

			TP_ARGS(dr))



DEFINE_SVC_DEFERRED_EVENT(drop);

DEFINE_SVC_DEFERRED_EVENT(revisit);

DEFINE_SVC_DEFERRED_EVENT(queue);

DEFINE_SVC_DEFERRED_EVENT(recv);



TRACE_EVENT(svcsock_new_socket,

	TP_PROTO(

net/sunrpc/svc_xprt.c

+6 −6
Original line number Diff line number Diff line
@@ -1145,16 +1145,15 @@ static void svc_revisit(struct cache_deferred_req *dreq, int too_many) 
	set_bit(XPT_DEFERRED, &xprt->xpt_flags);

	if (too_many || test_bit(XPT_DEAD, &xprt->xpt_flags)) {

		spin_unlock(&xprt->xpt_lock);

		dprintk("revisit canceled\n");

		trace_svc_defer_drop(dr);

		svc_xprt_put(xprt);

		trace_svc_drop_deferred(dr);

		kfree(dr);

		return;

	}

	dprintk("revisit queued\n");

	dr->xprt = NULL;

	list_add(&dr->handle.recent, &xprt->xpt_deferred);

	spin_unlock(&xprt->xpt_lock);

	trace_svc_defer_queue(dr);

	svc_xprt_enqueue(xprt);

	svc_xprt_put(xprt);

}
@@ -1200,22 +1199,24 @@ static struct cache_deferred_req *svc_defer(struct cache_req *req) 
		memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip,

		       dr->argslen << 2);

	}

	trace_svc_defer(rqstp);

	svc_xprt_get(rqstp->rq_xprt);

	dr->xprt = rqstp->rq_xprt;

	set_bit(RQ_DROPME, &rqstp->rq_flags);



	dr->handle.revisit = svc_revisit;

	trace_svc_defer(rqstp);

	return &dr->handle;

}



/*

 * recv data from a deferred request into an active one

 */

static int svc_deferred_recv(struct svc_rqst *rqstp)

static noinline int svc_deferred_recv(struct svc_rqst *rqstp)

{

	struct svc_deferred_req *dr = rqstp->rq_deferred;



	trace_svc_defer_recv(dr);



	/* setup iov_base past transport header */

	rqstp->rq_arg.head[0].iov_base = dr->args + (dr->xprt_hlen>>2);

	/* The iov_len does not include the transport header bytes */
@@ -1246,7 +1247,6 @@ static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt) 
				struct svc_deferred_req,

				handle.recent);

		list_del_init(&dr->handle.recent);

		trace_svc_revisit_deferred(dr);

	} else

		clear_bit(XPT_DEFERRED, &xprt->xpt_flags);

	spin_unlock(&xprt->xpt_lock);

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