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From: Chuck Lever <chuck.lever@oracle.com>
To: bfields@fieldses.org
Cc: linux-nfs@vger.kernel.org, linux-rdma@vger.kernel.org
Subject: [PATCH v3 30/32] SUNRPC: Clean up request deferral tracepoints
Date: Thu, 21 May 2020 10:36:21 -0400
Message-ID: <20200521143621.3557.75072.stgit@klimt.1015granger.net> (raw)
In-Reply-To: <20200521141100.3557.17098.stgit@klimt.1015granger.net>

- 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: Chuck Lever <chuck.lever@oracle.com>
---
 include/trace/events/sunrpc.h |   11 ++++++++---
 net/sunrpc/svc_xprt.c         |   12 ++++++------
 2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h
index 2a7f6f83341f..852413cbb7d9 100644
--- a/include/trace/events/sunrpc.h
+++ b/include/trace/events/sunrpc.h
@@ -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(
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index 0a546ef02dde..c1ff8cdb5b2b 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -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);


  parent reply index

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-21 14:33 [PATCH v3 00/32] Possible NFSD patches for v5.8 Chuck Lever
2020-05-21 14:33 ` [PATCH v3 01/32] SUNRPC: Move xpt_mutex into socket xpo_sendto methods Chuck Lever
2020-05-21 14:33 ` [PATCH v3 02/32] svcrdma: Clean up the tracing for rw_ctx_init errors Chuck Lever
2020-05-21 14:33 ` [PATCH v3 03/32] svcrdma: Clean up handling of get_rw_ctx errors Chuck Lever
2020-05-21 14:34 ` [PATCH v3 04/32] svcrdma: Trace page overruns when constructing RDMA Reads Chuck Lever
2020-05-21 14:34 ` [PATCH v3 05/32] svcrdma: trace undersized Write chunks Chuck Lever
2020-05-21 14:34 ` [PATCH v3 06/32] svcrdma: Fix backchannel return code Chuck Lever
2020-05-21 14:34 ` [PATCH v3 07/32] svcrdma: Remove backchannel dprintk call sites Chuck Lever
2020-05-21 14:34 ` [PATCH v3 08/32] svcrdma: Rename tracepoints that record header decoding errors Chuck Lever
2020-05-21 14:34 ` [PATCH v3 09/32] svcrdma: Remove the SVCRDMA_DEBUG macro Chuck Lever
2020-05-21 14:34 ` [PATCH v3 10/32] svcrdma: Displayed remote IP address should match stored address Chuck Lever
2020-05-21 14:34 ` [PATCH v3 11/32] svcrdma: Add tracepoints to report ->xpo_accept failures Chuck Lever
2020-05-21 14:34 ` [PATCH v3 12/32] SUNRPC: Remove kernel memory address from svc_xprt tracepoints Chuck Lever
2020-05-21 14:34 ` [PATCH v3 13/32] SUNRPC: Tracepoint to record errors in svc_xpo_create() Chuck Lever
2020-05-21 14:34 ` [PATCH v3 14/32] SUNRPC: Trace a few more generic svc_xprt events Chuck Lever
2020-05-21 14:35 ` [PATCH v3 15/32] SUNRPC: Remove "#include <trace/events/skb.h>" Chuck Lever
2020-05-21 14:35 ` [PATCH v3 16/32] SUNRPC: Add more svcsock tracepoints Chuck Lever
2020-05-21 14:35 ` [PATCH v3 17/32] SUNRPC: Replace dprintk call sites in TCP state change callouts Chuck Lever
2020-05-21 14:35 ` [PATCH v3 18/32] SUNRPC: Trace server-side rpcbind registration events Chuck Lever
2020-05-21 14:35 ` [PATCH v3 19/32] SUNRPC: Rename svc_sock::sk_reclen Chuck Lever
2020-05-21 14:35 ` [PATCH v3 20/32] SUNRPC: Restructure svc_tcp_recv_record() Chuck Lever
2020-05-21 14:35 ` [PATCH v3 21/32] SUNRPC: Replace dprintk() call sites in TCP receive path Chuck Lever
2020-05-21 14:35 ` [PATCH v3 22/32] SUNRPC: Refactor recvfrom path dealing with incomplete TCP receives Chuck Lever
2020-05-21 14:35 ` [PATCH v3 23/32] SUNRPC: Clean up svc_release_skb() functions Chuck Lever
2020-05-21 14:35 ` [PATCH v3 24/32] SUNRPC: Refactor svc_recvfrom() Chuck Lever
2020-05-21 14:35 ` [PATCH v3 25/32] SUNRPC: Restructure svc_udp_recvfrom() Chuck Lever
2020-05-21 14:36 ` [PATCH v3 26/32] SUNRPC: svc_show_status() macro should have enum definitions Chuck Lever
2020-05-21 14:36 ` [PATCH v3 27/32] NFSD: Add tracepoints to NFSD's duplicate reply cache Chuck Lever
2020-05-21 14:36 ` [PATCH v3 28/32] NFSD: Add tracepoints to the NFSD state management code Chuck Lever
2020-05-21 14:36 ` [PATCH v3 29/32] NFSD: Add tracepoints for monitoring NFSD callbacks Chuck Lever
2020-05-21 14:36 ` Chuck Lever [this message]
2020-05-21 14:36 ` [PATCH v3 31/32] NFSD: Squash an annoying compiler warning Chuck Lever
2020-05-21 14:36 ` [PATCH v3 32/32] NFSD: Fix improperly-formatted Doxygen comments Chuck Lever

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