High CPU utilization , is wait event cursor: pin S wait on X and library cache lock related ?

Hi everyone ,
        we have incident causing system response very slow with very bad response time, below top 5 wait events from AWR (RAC database)

Event Waits Time(s) Avg Wait(ms) % Total Call Time Wait Class
latch: cache buffers chains 122,492 198,139 1,618 16.8 Concurrency
gc buffer busy 119,903 83,248 694 7.1 Cluster
cursor: pin S 18,674,280 72,651 4 6.2 Other
log file sync 639,867 66,673 104 5.7
Commit latch free 143,519 54,239 378 4.6 Other

 
                 Oracle support clearly identified the issue with latch cache buffer chains as SQL statement executed around 35000 times which is too high based on execution plan . and they suggest to tune SQL statements .


          my question is cursor: pin S wait on X and  library cache lock related ot it is just a symptoms , and is