Priority of socket manager

Hi:

Is there a way to set the priority of the socket manager task Tcpip on
boot-up ?

I have also noticed that changing the priority of Tcpip while it is running,
using for example

slay -P xx Tcpip


gives odd results, ie trying to set it to priority 27 results in a priority
of 22, or sometimes 18 !!
Similarly using renice -5 Tcpip will boost it priority (not necessarily by
5) but once the priority has reached 29 the same command will reduce the
priority. Strange. Does anyone know what is going on here ?


Jim Rennie

“Jim Rennie” <rennie@sedsystems.ca> wrote in message
news:arm1m3$rlm$1@inn.qnx.com

Hi:

Is there a way to set the priority of the socket manager task Tcpip on
boot-up ?

I have also noticed that changing the priority of Tcpip while it is
running,
using for example

slay -P xx Tcpip


gives odd results, ie trying to set it to priority 27 results in a
priority
of 22, or sometimes 18 !!
Similarly using renice -5 Tcpip will boost it priority (not necessarily by
5) but once the priority has reached 29 the same command will reduce the
priority. Strange. Does anyone know what is going on here ?

Tcpip priority floats. I beleive there is an option (run time arguemnt) to
freeze it.
Why do you need to change the priority?


Jim Rennie

Jim Rennie <rennie@sedsystems.ca> wrote:

Hi:

Is there a way to set the priority of the socket manager task Tcpip on
boot-up ?

Won’t help.

I have also noticed that changing the priority of Tcpip while it is running,
using for example

slay -P xx Tcpip



gives odd results, ie trying to set it to priority 27 results in a priority
of 22, or sometimes 18 !!
Similarly using renice -5 Tcpip will boost it priority (not necessarily by
5) but once the priority has reached 29 the same command will reduce the
priority. Strange. Does anyone know what is going on here ?

Yup… it has set the _PPF_PRIORITY_FLOAT flag. If you do a “sin fl”

0 244 //61/usr/ucb/Tcpip RECV 0 -f-Z---------F3-------S-c-fr----
^
Says this server will run at its client’s priority. (There is a small
section on “Client-driven priority” in the System Architecture guide
that talks about this a bit. Many servers are configured this way,
including Tcpip, Pipe, Fsys, and Photon for examples.)

-David

QNX Training Services
http://www.qnx.com/support/training/
Please followup in this newsgroup if you have further questions.

Mario Charest postmaster@127.0.0.1 wrote:


Tcpip priority floats. I beleive there is an option (run time arguemnt) to
freeze it.

I don’t think so. Fsys has a -F option to not float, but I’m not
sure Tcpip does.

-David

QNX Training Services
http://www.qnx.com/support/training/
Please followup in this newsgroup if you have further questions.

Hi:

In my application, I have bursty UDP traffic being read off a socket. I
have found that if the socket manager priority drops too low (ie relative to
the other application tasks and the ethernet driver), I lose packets - it
appears that the packets are overwritten in the hardware buffer since my
socket buffer is sufficiently large. If I could switch to TCP, I wouldn’t
have this problem but there is too much legacy infrastructure here to do
this.

Is the _ _PPF_PRIORITY_FLOAT flag set in the underlying Tcpip code ? Is
there any way external to the code to reset this flag to fix the priority ?


Jim

“David Gibbs” <dagibbs@qnx.com> wrote in message
news:arm338$hao$1@nntp.qnx.com

Jim Rennie <> rennie@sedsystems.ca> > wrote:
Hi:

Is there a way to set the priority of the socket manager task Tcpip on
boot-up ?

Won’t help.

I have also noticed that changing the priority of Tcpip while it is
running,
using for example

slay -P xx Tcpip


gives odd results, ie trying to set it to priority 27 results in a
priority
of 22, or sometimes 18 !!
Similarly using renice -5 Tcpip will boost it priority (not necessarily
by
5) but once the priority has reached 29 the same command will reduce the
priority. Strange. Does anyone know what is going on here ?

Yup… it has set the _PPF_PRIORITY_FLOAT flag. If you do a “sin fl”

0 244 //61/usr/ucb/Tcpip RECV
0 -f-Z---------F3-------S-c-fr----
^
Says this server will run at its client’s priority. (There is a small
section on “Client-driven priority” in the System Architecture guide
that talks about this a bit. Many servers are configured this way,
including Tcpip, Pipe, Fsys, and Photon for examples.)

-David

QNX Training Services
http://www.qnx.com/support/training/
Please followup in this newsgroup if you have further questions.