[PATCH 4.4 127/138] SUNRPC: Dont allocate a full sockaddr_storage for tracing

Greg Kroah-Hartman
2016-08-18T14:08:48Z

From: Trond Myklebust <trond.myklebust@primarydata.com>

commit db1bb44c4c7e8d49ed674dc59e5222d99c698088 upstream.

We're always tracing IPv4 or IPv6 addresses, so we can save a lot
of space on the ringbuffer by allocating the correct sockaddr size.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Fixes: 83a712e0afef "sunrpc: add some tracepoints around ..."
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
include/trace/events/sunrpc.h | 47 ++++++++++++++++++++++++++++++------------
1 file changed, 34 insertions(+), 13 deletions(-)

--- a/include/trace/events/sunrpc.h
+++ b/include/trace/events/sunrpc.h
@@ -529,20 +529,27 @@ TRACE_EVENT(svc_xprt_do_enqueue,

TP_STRUCT__entry(
__field(struct svc_xprt *, xprt)
- __field_struct(struct sockaddr_storage, ss)
__field(int, pid)
__field(unsigned long, flags)
+ __dynamic_array(unsigned char, addr, xprt != NULL ?
+ xprt->xpt_remotelen : 0)
),

TP_fast_assign(
__entry->xprt = xprt;
- xprt ? memcpy(&__entry->ss, &xprt->xpt_remote, sizeof(__entry->ss)) : memset(&__entry->ss, 0, sizeof(__entry->ss));
__entry->pid = rqst? rqst->rq_task->pid : 0;
- __entry->flags = xprt ? xprt->xpt_flags : 0;
+ if (xprt) {
+ memcpy(__get_dynamic_array(addr),
+ &xprt->xpt_remote,
+ xprt->xpt_remotelen);
+ __entry->flags = xprt->xpt_flags;
+ } else
+ __entry->flags = 0;
),

TP_printk("xprt=0x%p addr=%pIScp pid=%d flags=%s", __entry->xprt,
- (struct sockaddr *)&__entry->ss,
+ __get_dynamic_array_len(addr) != 0 ?
+ (struct sockaddr *)__get_dynamic_array(addr) : NULL,
__entry->pid, show_svc_xprt_flags(__entry->flags))
);

@@ -553,18 +560,25 @@ TRACE_EVENT(svc_xprt_dequeue,

TP_STRUCT__entry(
__field(struct svc_xprt *, xprt)
- __field_struct(struct sockaddr_storage, ss)
__field(unsigned long, flags)
+ __dynamic_array(unsigned char, addr, xprt != NULL ?
+ xprt->xpt_remotelen : 0)
),

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;
+ __entry->xprt = xprt;
+ if (xprt) {
+ memcpy(__get_dynamic_array(addr),
+ &xprt->xpt_remote,
+ xprt->xpt_remotelen);
+ __entry->flags = xprt->xpt_flags;
+ } else
+ __entry->flags = 0;
),

TP_printk("xprt=0x%p addr=%pIScp flags=%s", __entry->xprt,
- (struct sockaddr *)&__entry->ss,
+ __get_dynamic_array_len(addr) != 0 ?
+ (struct sockaddr *)__get_dynamic_array(addr) : NULL,
show_svc_xprt_flags(__entry->flags))
);

@@ -592,19 +606,26 @@ TRACE_EVENT(svc_handle_xprt,
TP_STRUCT__entry(
__field(struct svc_xprt *, xprt)
__field(int, len)
- __field_struct(struct sockaddr_storage, ss)
__field(unsigned long, flags)
+ __dynamic_array(unsigned char, addr, xprt != NULL ?
+ xprt->xpt_remotelen : 0)
),

TP_fast_assign(
__entry->xprt = xprt;
- xprt ? memcpy(&__entry->ss, &xprt->xpt_remote, sizeof(__entry->ss)) : memset(&__entry->ss, 0, sizeof(__entry->ss));
__entry->len = len;
- __entry->flags = xprt ? xprt->xpt_flags : 0;
+ if (xprt) {
+ memcpy(__get_dynamic_array(addr),
+ &xprt->xpt_remote,
+ xprt->xpt_remotelen);
+ __entry->flags = xprt->xpt_flags;
+ } else
+ __entry->flags = 0;
),

TP_printk("xprt=0x%p addr=%pIScp len=%d flags=%s", __entry->xprt,
- (struct sockaddr *)&__entry->ss,
+ __get_dynamic_array_len(addr) != 0 ?
+ (struct sockaddr *)__get_dynamic_array(addr) : NULL,
__entry->len, show_svc_xprt_flags(__entry->flags))
);
#endif /* _TRACE_SUNRPC_H */