need kernel tuning advice 3b2-310

[Greg Hackney]

I would appreciate any expert recommendations for tuning
the kernel on a 3B2/310 for better serial I/O performance.

The system has 2 MB of memory, is running S5R3.2.2, has 1
CDC Wren II disk, and a new HPP 4-port serial board. There is
no networking, no tape drive, no other boards, no MAU. It's
used primarily for Netnews via a Telebit.

Attached is the output of /etc/sysdef. Thanks in advance.
--
Greg

*
* 3B2 Configuration
*

  Boot program: /boot/KERNEL
  Time stamp:   Wed Mar 16 15:36:33 1988
*
* Devices
*
  ports	board=1
  hdelog
  iuart
  idisk
  mem
  gentty
  sxt
  xt
  prf
*
* Loadable Objects
*
  shm
  sem
  msg
  ipc
  s5
  disp
  mau
*
* System Configuration
*
  rootdev	 idisk	minor=0
  swapdev	 idisk	minor=1	swplo=0	nswap=10106
  pipedev	 idisk	minor=0
*
* Tunable Parameters
*
   250	buffers in buffer cache (NBUF)
    30	entries in callout table (NCALL)
   150	inodes  (NINODE)
   150	s5inodes  (NS5INODE)
   150	entries in file table (NFILE)
    25	entries in mount table (NMOUNT)
    60	entries in proc table (NPROC)
   210	entries in shared region table (NREGION)
   120	clist buffers (NCLIST)
    25	processes per user id (MAXUP)
    64	hash slots for buffer cache (NHBUF)
    20	buffers for physical I/O (NPBUF)
    50	size of system virtual space map (SPTMAP)
    16	fraction of memory for vhandlow (VHNDFRAC)
     0	maximum physical memory to use (MAXPMEM)
    10	auto update time limit in seconds (NAUTOUP)
    20	maximum number of open files per process (NOFILES)
     0	number of streams queues (NQUEUE)
     0	number of streams head structures (NSTREAM)
     0	number of 4096 bytes stream buffers (NBLK4096)
     0	number of 2048 bytes stream buffers (NBLK2048)
     0	number of 1024 bytes stream buffers (NBLK1024)
     0	number of 512 bytes stream buffers (NBLK512)
     0	number of 256 bytes stream buffers (NBLK256)
     0	number of 128 bytes stream buffers (NBLK128)
     0	number of 64 bytes stream buffers (NBLK64)
     0	number of 16 bytes stream buffers (NBLK16)
     0	number of 4 bytes stream buffers (NBLK4)
  8192  maximum size of user's virtual address space in pages (MAXUMEM)
  8192  for package compatibility equal to MAXUMEM (MAXMEM)
    25  page stealing low water mark (GPGSLO)
    40  page stealing high water mark (GPGSHI)
     1  vhand wake up rate (VHANDR)
    42  awaken vhand if free memory less than vhandl (VHANDL)
     1  bdflush run rate (BDFLUSHR)
    25  minimum resident memory for avoiding deadlock (MINARMEM)
    25  minimum swapable memory for avoiding deadlock (MINASMEM)
     1  maximum number of pages swapped out (MAXSC)
     1  maximum number of pages saved (MAXFC)
*
* Utsname Tunables
*
     3.2  release (REL)
   moxie  node name (NODE)
   moxie  system name (SYS)
       2  version (VER)
*
* Streams Tunables
*
     0	number of multiplexor links (NMUXLINK)
     9	maximum number of pushes allowed (NSTRPUSH)
     0	initial number of stream event calls (NSTREVENT)
     0	page limit for event cell allocation (MAXSEPGCNT)
  4096	maximum stream message size (STRMSGSZ)
  1024	max size of ctl part of message (STRCTLSZ)
    80	max low priority block usage (STRLOFRAC)
    90	max medium priority block usage (STRMEDFRAC)
*
* RFS Tunables
*
     0	entries in server mount table (NSRMOUNT)
*
* IPC Messages
*
   100	entries in msg map (MSGMAP)
  2048	max message size (MSGMAX)
  4096	max bytes on queue (MSGMNB)
    50	message queue identifiers (MSGMNI)
     8	message segment size (MSGSSZ)
    40	system message headers (MSGTQL)
  1024	message segments (MSGSEG)
*
* IPC Semaphores
*
    10	entries in semaphore map (SEMMAP)
    10	semaphore identifiers (SEMMNI)
    60	semaphores in system (SEMMNS)
    30	undo structures in system (SEMMNU)
    25	max semaphores per id (SEMMSL)
    10	max operations per semop call (SEMOPM)
    10	max undo entries per process (SEMUME)
 32767	semaphore maximum value (SEMVMX)
 16384	adjust on exit max value (SEMAEM)
*
* IPC Shared Memory
*
131072	max shared memory segment size (SHMMAX)
     1	min shared memory segment size (SHMMIN)
   100	shared memory identifiers (SHMMNI)
     6	max attached shm segments per process (SHMSEG)
   512	max in use shared memory (SHMALL)
*
* File and Record Locking
*
   100	records configured on system (FLCKREC)