From 55f5088c22cc83dbc64394abfbf76cd1ff5e7cd0 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Tue, 27 Mar 2018 10:52:27 -0400 Subject: svc: Report xprt dequeue latency Record the time between when a rqstp is enqueued on a transport and when it is dequeued. This includes how long the rqstp waits on the queue and how long it takes the kernel scheduler to wake a nfsd thread to service it. The svc_xprt_dequeue trace point is altered to include the number of microseconds between xprt_enqueue and xprt_dequeue. Signed-off-by: Chuck Lever Signed-off-by: J. Bruce Fields --- include/linux/sunrpc/svc.h | 1 + include/trace/events/sunrpc.h | 30 ++++++++++++++++++++++++++---- net/sunrpc/svc_xprt.c | 4 ++-- 3 files changed, 29 insertions(+), 6 deletions(-) diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h index 3bd7504066e1..dc4c009deec1 100644 --- a/include/linux/sunrpc/svc.h +++ b/include/linux/sunrpc/svc.h @@ -272,6 +272,7 @@ struct svc_rqst { #define RQ_BUSY (6) /* request is busy */ #define RQ_DATA (7) /* request has data */ unsigned long rq_flags; /* flags field */ + ktime_t rq_qtime; /* enqueue time */ void * rq_argp; /* decoded arguments */ void * rq_resp; /* xdr'd results */ diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h index 1b383f71ccd7..922cb8968fb2 100644 --- a/include/trace/events/sunrpc.h +++ b/include/trace/events/sunrpc.h @@ -657,14 +657,36 @@ DECLARE_EVENT_CLASS(svc_xprt_event, show_svc_xprt_flags(__entry->flags)) ); -DEFINE_EVENT(svc_xprt_event, svc_xprt_dequeue, - TP_PROTO(struct svc_xprt *xprt), - TP_ARGS(xprt)); - DEFINE_EVENT(svc_xprt_event, svc_xprt_no_write_space, TP_PROTO(struct svc_xprt *xprt), TP_ARGS(xprt)); +TRACE_EVENT(svc_xprt_dequeue, + TP_PROTO(struct svc_rqst *rqst), + + TP_ARGS(rqst), + + TP_STRUCT__entry( + __field(struct svc_xprt *, xprt) + __field(unsigned long, flags) + __field(unsigned long, wakeup) + __string(addr, rqst->rq_xprt->xpt_remotebuf) + ), + + TP_fast_assign( + __entry->xprt = rqst->rq_xprt; + __entry->flags = rqst->rq_xprt->xpt_flags; + __entry->wakeup = ktime_to_us(ktime_sub(ktime_get(), + rqst->rq_qtime)); + __assign_str(addr, rqst->rq_xprt->xpt_remotebuf); + ), + + TP_printk("xprt=%p addr=%s flags=%s wakeup-us=%lu", + __entry->xprt, __get_str(addr), + show_svc_xprt_flags(__entry->flags), + __entry->wakeup) +); + TRACE_EVENT(svc_wake_up, TP_PROTO(int pid), diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c index a7425da14f5b..5185efb9027b 100644 --- a/net/sunrpc/svc_xprt.c +++ b/net/sunrpc/svc_xprt.c @@ -409,6 +409,7 @@ void svc_xprt_do_enqueue(struct svc_xprt *xprt) if (test_and_set_bit(RQ_BUSY, &rqstp->rq_flags)) continue; atomic_long_inc(&pool->sp_stats.threads_woken); + rqstp->rq_qtime = ktime_get(); wake_up_process(rqstp->rq_task); goto out_unlock; } @@ -530,7 +531,6 @@ void svc_wake_up(struct svc_serv *serv) if (test_bit(RQ_BUSY, &rqstp->rq_flags)) continue; 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; @@ -726,7 +726,7 @@ out_found: rqstp->rq_chandle.thread_wait = 5*HZ; else rqstp->rq_chandle.thread_wait = 1*HZ; - trace_svc_xprt_dequeue(rqstp->rq_xprt); + trace_svc_xprt_dequeue(rqstp); return rqstp->rq_xprt; } -- cgit