Commit 83a712e0 authored by Jeff Layton's avatar Jeff Layton Committed by J. Bruce Fields

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: default avatarJeff Layton <jlayton@primarydata.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent b1691bc0
...@@ -8,6 +8,7 @@ ...@@ -8,6 +8,7 @@
#include <linux/sunrpc/clnt.h> #include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/svc.h> #include <linux/sunrpc/svc.h>
#include <linux/sunrpc/xprtsock.h> #include <linux/sunrpc/xprtsock.h>
#include <linux/sunrpc/svc_xprt.h>
#include <net/tcp_states.h> #include <net/tcp_states.h>
#include <linux/net.h> #include <linux/net.h>
#include <linux/tracepoint.h> #include <linux/tracepoint.h>
...@@ -480,6 +481,99 @@ DEFINE_EVENT(svc_rqst_status, svc_send, ...@@ -480,6 +481,99 @@ DEFINE_EVENT(svc_rqst_status, svc_send,
TP_PROTO(struct svc_rqst *rqst, int status), TP_PROTO(struct svc_rqst *rqst, int status),
TP_ARGS(rqst, status)); TP_ARGS(rqst, status));
#define show_svc_xprt_flags(flags) \
__print_flags(flags, "|", \
{ (1UL << XPT_BUSY), "XPT_BUSY"}, \
{ (1UL << XPT_CONN), "XPT_CONN"}, \
{ (1UL << XPT_CLOSE), "XPT_CLOSE"}, \
{ (1UL << XPT_DATA), "XPT_DATA"}, \
{ (1UL << XPT_TEMP), "XPT_TEMP"}, \
{ (1UL << XPT_DEAD), "XPT_DEAD"}, \
{ (1UL << XPT_CHNGBUF), "XPT_CHNGBUF"}, \
{ (1UL << XPT_DEFERRED), "XPT_DEFERRED"}, \
{ (1UL << XPT_OLD), "XPT_OLD"}, \
{ (1UL << XPT_LISTENER), "XPT_LISTENER"}, \
{ (1UL << XPT_CACHE_AUTH), "XPT_CACHE_AUTH"}, \
{ (1UL << XPT_LOCAL), "XPT_LOCAL"})
TRACE_EVENT(svc_xprt_do_enqueue,
TP_PROTO(struct svc_xprt *xprt, struct svc_rqst *rqst),
TP_ARGS(xprt, rqst),
TP_STRUCT__entry(
__field(struct svc_xprt *, xprt)
__field(struct svc_rqst *, rqst)
),
TP_fast_assign(
__entry->xprt = xprt;
__entry->rqst = rqst;
),
TP_printk("xprt=0x%p addr=%pIScp pid=%d flags=%s", __entry->xprt,
(struct sockaddr *)&__entry->xprt->xpt_remote,
__entry->rqst ? __entry->rqst->rq_task->pid : 0,
show_svc_xprt_flags(__entry->xprt->xpt_flags))
);
TRACE_EVENT(svc_xprt_dequeue,
TP_PROTO(struct svc_xprt *xprt),
TP_ARGS(xprt),
TP_STRUCT__entry(
__field(struct svc_xprt *, xprt)
__field_struct(struct sockaddr_storage, ss)
__field(unsigned long, flags)
),
TP_fast_assign(
__entry->xprt = xprt,
xprt ? memcpy(&__entry->ss, &xprt->xpt_remote, sizeof(__entry->ss)) : memset(&__entry->ss, 0, sizeof(__entry->ss));
__entry->flags = xprt ? xprt->xpt_flags : 0;
),
TP_printk("xprt=0x%p addr=%pIScp flags=%s", __entry->xprt,
(struct sockaddr *)&__entry->ss,
show_svc_xprt_flags(__entry->flags))
);
TRACE_EVENT(svc_wake_up,
TP_PROTO(int pid),
TP_ARGS(pid),
TP_STRUCT__entry(
__field(int, pid)
),
TP_fast_assign(
__entry->pid = pid;
),
TP_printk("pid=%d", __entry->pid)
);
TRACE_EVENT(svc_handle_xprt,
TP_PROTO(struct svc_xprt *xprt, int len),
TP_ARGS(xprt, len),
TP_STRUCT__entry(
__field(struct svc_xprt *, xprt)
__field(int, len)
),
TP_fast_assign(
__entry->xprt = xprt;
__entry->len = len;
),
TP_printk("xprt=0x%p addr=%pIScp len=%d flags=%s", __entry->xprt,
(struct sockaddr *)&__entry->xprt->xpt_remote, __entry->len,
show_svc_xprt_flags(__entry->xprt->xpt_flags))
);
#endif /* _TRACE_SUNRPC_H */ #endif /* _TRACE_SUNRPC_H */
#include <trace/define_trace.h> #include <trace/define_trace.h>
...@@ -322,12 +322,12 @@ static bool svc_xprt_has_something_to_do(struct svc_xprt *xprt) ...@@ -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) static void svc_xprt_do_enqueue(struct svc_xprt *xprt)
{ {
struct svc_pool *pool; struct svc_pool *pool;
struct svc_rqst *rqstp; struct svc_rqst *rqstp = NULL;
int cpu; int cpu;
bool queued = false; bool queued = false;
if (!svc_xprt_has_something_to_do(xprt)) if (!svc_xprt_has_something_to_do(xprt))
return; goto out;
/* Mark transport as busy. It will remain in this state until /* Mark transport as busy. It will remain in this state until
* the provider calls svc_xprt_received. We update XPT_BUSY * the provider calls svc_xprt_received. We update XPT_BUSY
...@@ -337,7 +337,7 @@ static void svc_xprt_do_enqueue(struct svc_xprt *xprt) ...@@ -337,7 +337,7 @@ static void svc_xprt_do_enqueue(struct svc_xprt *xprt)
if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) { if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) {
/* Don't enqueue transport while already enqueued */ /* Don't enqueue transport while already enqueued */
dprintk("svc: transport %p busy, not enqueued\n", xprt); dprintk("svc: transport %p busy, not enqueued\n", xprt);
return; goto out;
} }
cpu = get_cpu(); cpu = get_cpu();
...@@ -377,7 +377,7 @@ static void svc_xprt_do_enqueue(struct svc_xprt *xprt) ...@@ -377,7 +377,7 @@ static void svc_xprt_do_enqueue(struct svc_xprt *xprt)
atomic_long_inc(&pool->sp_stats.threads_woken); atomic_long_inc(&pool->sp_stats.threads_woken);
wake_up_process(rqstp->rq_task); wake_up_process(rqstp->rq_task);
put_cpu(); put_cpu();
return; goto out;
} }
rcu_read_unlock(); rcu_read_unlock();
...@@ -396,7 +396,10 @@ static void svc_xprt_do_enqueue(struct svc_xprt *xprt) ...@@ -396,7 +396,10 @@ static void svc_xprt_do_enqueue(struct svc_xprt *xprt)
spin_unlock_bh(&pool->sp_lock); spin_unlock_bh(&pool->sp_lock);
goto redo_search; goto redo_search;
} }
rqstp = NULL;
put_cpu(); 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) ...@@ -420,7 +423,7 @@ static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool)
struct svc_xprt *xprt = NULL; struct svc_xprt *xprt = NULL;
if (list_empty(&pool->sp_sockets)) if (list_empty(&pool->sp_sockets))
return NULL; goto out;
spin_lock_bh(&pool->sp_lock); spin_lock_bh(&pool->sp_lock);
if (likely(!list_empty(&pool->sp_sockets))) { if (likely(!list_empty(&pool->sp_sockets))) {
...@@ -433,7 +436,8 @@ static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool) ...@@ -433,7 +436,8 @@ static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool)
xprt, atomic_read(&xprt->xpt_ref.refcount)); xprt, atomic_read(&xprt->xpt_ref.refcount));
} }
spin_unlock_bh(&pool->sp_lock); spin_unlock_bh(&pool->sp_lock);
out:
trace_svc_xprt_dequeue(xprt);
return xprt; return xprt;
} }
...@@ -515,6 +519,7 @@ void svc_wake_up(struct svc_serv *serv) ...@@ -515,6 +519,7 @@ void svc_wake_up(struct svc_serv *serv)
rcu_read_unlock(); rcu_read_unlock();
dprintk("svc: daemon %p woken up.\n", rqstp); dprintk("svc: daemon %p woken up.\n", rqstp);
wake_up_process(rqstp->rq_task); wake_up_process(rqstp->rq_task);
trace_svc_wake_up(rqstp->rq_task->pid);
return; return;
} }
rcu_read_unlock(); rcu_read_unlock();
...@@ -522,6 +527,7 @@ void svc_wake_up(struct svc_serv *serv) ...@@ -522,6 +527,7 @@ void svc_wake_up(struct svc_serv *serv)
/* No free entries available */ /* No free entries available */
set_bit(SP_TASK_PENDING, &pool->sp_flags); set_bit(SP_TASK_PENDING, &pool->sp_flags);
smp_wmb(); smp_wmb();
trace_svc_wake_up(0);
} }
EXPORT_SYMBOL_GPL(svc_wake_up); EXPORT_SYMBOL_GPL(svc_wake_up);
...@@ -740,7 +746,7 @@ static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt) ...@@ -740,7 +746,7 @@ static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt)
dprintk("svc_recv: found XPT_CLOSE\n"); dprintk("svc_recv: found XPT_CLOSE\n");
svc_delete_xprt(xprt); svc_delete_xprt(xprt);
/* Leave XPT_BUSY set on the dead xprt: */ /* Leave XPT_BUSY set on the dead xprt: */
return 0; goto out;
} }
if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) { if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) {
struct svc_xprt *newxpt; struct svc_xprt *newxpt;
...@@ -771,6 +777,8 @@ static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt) ...@@ -771,6 +777,8 @@ static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt)
} }
/* clear XPT_BUSY: */ /* clear XPT_BUSY: */
svc_xprt_received(xprt); svc_xprt_received(xprt);
out:
trace_svc_handle_xprt(xprt, len);
return len; return len;
} }
......
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