[Linuxptp-users] The ptp4l application seems to have a memory leak (increase of memory allocation)

[Mario M. <Mar...@we...>]

 Hallo PTP4l members,

I could observe a memory increasing by long term test of PTP4L application. 
(cat /proc/[PID of App]/status)

The background of this memory leak is message pool handling in the function 
msg_allocate(void)  and msg_put().

In the current implementation of this functions would every call of 
msg_allocate()  make a new  message allocation,  because the condition 
if(!m)  in msg_put() should  always false and  in the consequently is 
msg_pool always empty.

My patch suggestion:

@@ -146,12 +147,20 @@ struct ptp_message *msg_allocate(void)
  struct message_storage *s;
  struct ptp_message *m = TAILQ_FIRST(&msg_pool);
  if (!m) {
+  // pr_notice("ptp_message alloc new \n");
   s = malloc(sizeof(*s));
   if (s) {
    m = &s->msg;
-   m->refcnt = 1;
+  } else {
+   return NULL;
   }
+ } else {
+  TAILQ_REMOVE(&msg_pool, m, list);
+  //pr_notice("ptp_message\n");
  }
+
+ memset(m, 0, sizeof(*m));
+ m->refcnt = 1;
  return m;
 }

@@ -330,8 +339,11 @@ void msg_print(struct ptp_message *m, FILE *fp)
 void msg_put(struct ptp_message *m)
 {
  m->refcnt--;
- if (!m)
+ if (m != TAILQ_FIRST(&msg_pool) && m->refcnt == 0 )
+ {
+  // pr_notice("TAILQ_INSERT_HEAD  %s 
%i",msg_type_string(msg_type(m)),m->refcnt);
   TAILQ_INSERT_HEAD(&msg_pool, m, list);
+ }
 }

 int msg_sots_missing(struct ptp_message *m)
diff --git a/port.c b/port.c
index bf5738f..9d3a966 100644
--- a/port.c
+++ b/port.c
@@ -366,7 +366,6 @@ static int port_pdelay_request(struct port *p)
  msg = msg_allocate();
  if (!msg)
   return -1;
- memset(msg, 0, sizeof(*msg));

  pdulen = sizeof(struct pdelay_req_msg);
  msg->hwts.type = p->timestamping;
@@ -414,7 +413,6 @@ static int port_delay_request(struct port *p)
  msg = msg_allocate();
  if (!msg)
   return -1;
- memset(msg, 0, sizeof(*msg));

  pdulen = sizeof(struct delay_req_msg);
  msg->hwts.type = p->timestamping;
@@ -461,7 +459,6 @@ static int port_tx_announce(struct port *p)
  msg = msg_allocate();
  if (!msg)
   return -1;
- memset(msg, 0, sizeof(*msg));

  pdulen = sizeof(struct announce_msg);
  msg->hwts.type = p->timestamping;
@@ -523,8 +520,6 @@ static int port_tx_sync(struct port *p)
   msg_put(msg);
   return -1;
  }
- memset(msg, 0, sizeof(*msg));
- memset(fup, 0, sizeof(*fup));

  pdulen = sizeof(struct sync_msg);
  msg->hwts.type = p->timestamping;
@@ -767,7 +762,6 @@ static int process_delay_req(struct port *p, struct 
ptp_message *m)
  msg = msg_allocate();
  if (!msg)
   return -1;
- memset(msg, 0, sizeof(*msg));

  pdulen = sizeof(struct delay_resp_msg);
  msg->hwts.type = p->timestamping;
@@ -895,8 +889,6 @@ static int process_pdelay_req(struct port *p, struct 
ptp_message *m)
   msg_put(rsp);
   return -1;
  }
- memset(rsp, 0, sizeof(*rsp));
- memset(fup, 0, sizeof(*fup));

  rsp_len = sizeof(struct pdelay_resp_msg);
  rsp->hwts.type = p->timestamping;



Attached on this email you could also find patch file

I think another good way to solve this behavior is to use a circular message 
pool with a fix size.

What do you think from this idea?

Best regards,

Mario