Experimental Physics and
Industrial Control System

I have made a start by quickly compiling teh following table from vxWorks
console output and what I found in the sources. It might be incomplete
and/or erroneous.

ipToAsciiPr 189 10=Low ???

Apart from filling in missing information (see question marks), it might be
sensible to have some sort of rationale for the relative priorities. For
instance, it is unclear to me why the timerQueue task has higher priority
than cbLow task.

I'm really unclear about another task where I wonder if it
disturbs the intended order of things:
On vxWorks, there's the "tNetTask" at a very high priority.
At the SNS, we have had problems whenever that task doesn't get
to run as often as it wants to. When computations that can take
millisecs run higher than tNetTask, the result is an irrecoverable
messup of the network stack, at least with our 5.5.1 kernels
on MVME 2100 CPUs.
It might make sense that the network chips require to be serviced
right away, or maybe that's just an imperfection in our version
of the network code, fixed in more recent vxWorks versions,
but in any case:
Doesn't a tNettask at a high priority mean that even if we
otherwise move all the CA tasks to the bottom, network
traffic will still disturb the scanning?

                            EPICS TASKS
======================================================================

    NAME        VX_PRI  OSI_PRI                    DESCRIPTION
-------------   ------  -------           ----------------------------
ts_Casync        109    90=High           drvTS (apsEvent module)
TSwdIncTime      109    90=High           drvTS (apsEvent module)
cbHigh           128    71=ScanHigh+1     callback task (prio=high)
timerQueue       129    70=ScanHigh       scan task
scanOnce         129    70=ScanHigh       scan task
scan0.1          133    66=ScanLow+6      scan task
scan0.2          134    65=ScanLow+5      scan task
cbMedium         135    64=ScanLow+4      callback task (prio=medium)
scan0.5          135    64=ScanLow+4      scan task
scan1            136    63=ScanLow+3      scan task
scan2            137    62=ScanLow+2      scan task
scan5            138    61=ScanLow+1      scan task
scan10           139    60=ScanLow        scan task
timerQueue       139    60=ScanLow        epicsTimer
cbLow            140    59=ScanLow-1      callback task (prio=low)
asCaTask         142    57=ScanLow-3      access security
CAC-UDP          147    52=Medium+2       CA client
timerQueue       148    51=Medium+1       epicsTimer
CAC-event        148    51=Medium+1       CA client
dbCaLink         149    50=Medium         CA links (client? server?)
poolPoll         149    50=Medium         ???
CAC-event        178    21=CAServerLow+1  CA Server
CAS-TCP          181    18=CAServerLow-2  CA Server
CAS-beacon       182    17=CAServerLow-3  CA Server
CAS-UDP          183    16=CAServerLow-4  CA Server
errlog           189    10=Low            errlog
taskwd           189    10=Low            task watchdog
ipToAsciiPr      189    10=Low            ???
CAC-repeate      189    10=Low            CA Client (repeater)

Cheers
Ben
--
"Programming = Mathematics + Murphy's Law" (Dijkstra in EWD1008)

Replies:

RE: task priorities, busy cpu, and timeout Jeff Hill

References:

task priorities, busy cpu, and timeout Dennis Nicklaus

Re: task priorities, busy cpu, and timeout Andrew Johnson

Re: task priorities, busy cpu, and timeout Benjamin Franksen

Navigate by Date:

Prev: Re: ca_sg_put problem with DISP=1 Benjamin Franksen

Next: RE: task priorities, busy cpu, and timeout Jeff Hill

Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  <2007>  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  2022  2023  2024 

Navigate by Thread:

Prev: Re: task priorities, busy cpu, and timeout Benjamin Franksen

Next: RE: task priorities, busy cpu, and timeout Jeff Hill

Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  <2007>  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  2022  2023  2024