From 83a712e0afefaf68555f816ea78ecd2862c6cf30 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Fri, 21 Nov 2014 14:19:31 -0500 Subject: sunrpc: add some tracepoints around enqueue and dequeue of svc_xprt These were useful when I was tracking down a race condition between svc_xprt_do_enqueue and svc_get_next_xprt. Signed-off-by: Jeff Layton Signed-off-by: J. Bruce Fields --- net/sunrpc/svc_xprt.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) (limited to 'net/sunrpc') diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c index ed90d955f733..73d40bd1839a 100644 --- a/net/sunrpc/svc_xprt.c +++ b/net/sunrpc/svc_xprt.c @@ -322,12 +322,12 @@ static bool svc_xprt_has_something_to_do(struct svc_xprt *xprt) static void svc_xprt_do_enqueue(struct svc_xprt *xprt) { struct svc_pool *pool; - struct svc_rqst *rqstp; + struct svc_rqst *rqstp = NULL; int cpu; bool queued = false; if (!svc_xprt_has_something_to_do(xprt)) - return; + goto out; /* Mark transport as busy. It will remain in this state until * the provider calls svc_xprt_received. We update XPT_BUSY @@ -337,7 +337,7 @@ static void svc_xprt_do_enqueue(struct svc_xprt *xprt) if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) { /* Don't enqueue transport while already enqueued */ dprintk("svc: transport %p busy, not enqueued\n", xprt); - return; + goto out; } cpu = get_cpu(); @@ -377,7 +377,7 @@ redo_search: atomic_long_inc(&pool->sp_stats.threads_woken); wake_up_process(rqstp->rq_task); put_cpu(); - return; + goto out; } rcu_read_unlock(); @@ -396,7 +396,10 @@ redo_search: spin_unlock_bh(&pool->sp_lock); goto redo_search; } + rqstp = NULL; put_cpu(); +out: + trace_svc_xprt_do_enqueue(xprt, rqstp); } /* @@ -420,7 +423,7 @@ static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool) struct svc_xprt *xprt = NULL; if (list_empty(&pool->sp_sockets)) - return NULL; + goto out; spin_lock_bh(&pool->sp_lock); if (likely(!list_empty(&pool->sp_sockets))) { @@ -433,7 +436,8 @@ static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool) xprt, atomic_read(&xprt->xpt_ref.refcount)); } spin_unlock_bh(&pool->sp_lock); - +out: + trace_svc_xprt_dequeue(xprt); return xprt; } @@ -515,6 +519,7 @@ void svc_wake_up(struct svc_serv *serv) rcu_read_unlock(); dprintk("svc: daemon %p woken up.\n", rqstp); wake_up_process(rqstp->rq_task); + trace_svc_wake_up(rqstp->rq_task->pid); return; } rcu_read_unlock(); @@ -522,6 +527,7 @@ void svc_wake_up(struct svc_serv *serv) /* No free entries available */ set_bit(SP_TASK_PENDING, &pool->sp_flags); smp_wmb(); + trace_svc_wake_up(0); } EXPORT_SYMBOL_GPL(svc_wake_up); @@ -740,7 +746,7 @@ static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt) dprintk("svc_recv: found XPT_CLOSE\n"); svc_delete_xprt(xprt); /* Leave XPT_BUSY set on the dead xprt: */ - return 0; + goto out; } if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) { struct svc_xprt *newxpt; @@ -771,6 +777,8 @@ static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt) } /* clear XPT_BUSY: */ svc_xprt_received(xprt); +out: + trace_svc_handle_xprt(xprt, len); return len; } -- cgit v1.2.3