2494526 - sp_sysmon hangs in routine pipe_read()

Every now and then sp_sysmon hangs, if running "dbcc stacktrace(spid=sysmon process id)", you would see it's hanging in routine pipe_read().

Example:
DBCC execution completed. If DBCC printed error messages, contact a user with System Administrator (SA) role.
Start dbcc stacktrace...
pc: 0x0000000001dc4762 upsleepgeneric+0x532()
pc: 0x0000000001a96b33 pipe_read+0x2a3()
pc: 0x000000000164a0d2 LePipeRWState::_LePrwsReadConstant(LeColumn*, pipe_client_rwmode, int)+0x152()
pc: 0x000000000164a91c LePipeRWState::LePrwsRWVtuple(LeVtuple*, pipe_client_rwmode, int)+0x11c()
...
...
dbcc stacktrace finished.

SAP Adaptive Server Enterprise 16.0 SP02 PL04 HF1

ASE, sysmon, pipe buffer, CR#808649, 808649, sybase, hang, max parallel degree , KBA , BC-SYB-ASE , Sybase ASE Database Platform (non Business Suite) , Bug Filed