[j-nsp] syslog rsmon

[Juniper]

Hello,

I need help with syslog and rsmon. For a few days, I have the following 
entry in the log that is repeated every minute:

Sep 23 10:00:45 ***.net ssb RSMON: Resource Category:jtree  Instance:jtree0 Type:free-pages Available:390 is less than LWM limit:406, rsmon_syslog_limit()  
Sep 23 09:59:45 ***.net ssb RSMON: Resource Category:jtree  Instance:jtree0 Type:free-pages Available:390 is less than LWM limit:406, rsmon_syslog_limit()
...


I'm looking for this problem on Internet and in Knowledge Base of 
Juniper but I have not found nothing.
If anyone had any idea about the matter, would appreciate your help.

Thanks in advance,