Reset the max_wait column on v$session_event
                                                 Last update (2008-06-02 15:21:30)
                                                                                                                   Date added (2008-06-02 15:15:22)

Summary
You can reset the timers displayed by MAX_WAIT in GV$SESSION_EVENT and MAXIORTM and MAXIOWTM in GV$FILESTAT by executing Dbms_System.kcfrms;

SELECT SID, event, max_wait FROM v$session_event 
WHERE max_wait>0 
ORDER BY max_wait DESC;

       SID EVENT                                                              MAX_WAIT
---------- ---------------------------------------------------------------- ----------
       429 SQL*Net message from client                                           18986
       482 Streams AQ: waiting for time management or cleanup tasks              17490
       488 Streams AQ: waiting for time management or cleanup tasks              17490
       470 SQL*Net message from client                                           10285
       452 SQL*Net message from client                                            4203
       441 Streams AQ: qmn slave idle wait                                         977
       477 Streams AQ: qmn slave idle wait                                         977
       461 Streams AQ: qmn slave idle wait                                         977
       483 Streams AQ: qmn coordinator idle wait                                   781
       462 SQL*Net message from client                                             489
       491 rdbms ipc message                                                       488

EXEC Dbms_System.kcfrms;

       SID EVENT                                                              MAX_WAIT
---------- ---------------------------------------------------------------- ----------
       452 SQL*Net message from client                                             689
       462 SQL*Net message from client                                             489
       428 Streams AQ: waiting for messages in the queue                           488
       491 rdbms ipc message                                                       488
       497 rdbms ipc message                                                       294
       495 rdbms ipc message                                                       293
       418 jobq slave wait                                                         293
       490 rdbms ipc message                                                       293
       499 rdbms ipc message                                                       293
       494 rdbms ipc message                                                       293
       500 pmon timer                                                              293