RMAN HANGS

Bug 7595777 RMAN TAKES A LONG TIME BEFORE STARTING THE BACKUPNote 820856.1 High Waits On "Control File Sequential Read" During Rman Backup

use the below script to take backup:

run {
CONFIGURE DEVICE TYPE DISK PARALLELISM 12 BACKUP TYPE TO BACKUPSET;
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO  '/backup/rman_backup/rman/controlfile_backup/%F';
delete noprompt archivelog until time 'SYSDATE-1' backed up 1 times to disk;
crosscheck archivelog all;
delete noprompt expired archivelog all;
crosscheck backupset;
delete  noprompt expired backupset ;
backup as backupset datafile 70 tag 'TEST_FULL_BACKUP' format '/backup/rman_backup/rman/datafiles_backup/DATAFILE_%U';
}

RMAN hangs at starting after allocating channels:

Control file sequential read EVENT wait: