Why does pppd cause apps to load REALLY SLOW?

Why does pppd cause apps to load REALLY SLOW?

Post by Mr. Caldwe » Mon, 19 May 1997 04:00:00




>i really have NO IDEA why it's doing this, but when pppd is running, mc
>and *x take 10+ seconds to load up.. i'm really confused, any any
>help would be appreciated

First check that DNS is working reasonably well, if it's not see if
your ISP's backup works or implement local DNS for yourself (DNS Howto
for a cacheing DNS server).

Second get irqtune, it *really* helps, it puts the serial port at top
priority.

I load an IRC-II client with Lice and get on a good IRC server in
under 5 secs depending on traffic.

>btw, this is my first time using tin, so my email addr probably isn't right :)


 
 
 

Why does pppd cause apps to load REALLY SLOW?

Post by Ramesh Narayanaswam » Tue, 20 May 1997 04:00:00



> i really have NO IDEA why it's doing this, but when pppd is running, mc
> and *x take 10+ seconds to load up.. i'm really confused, any any
> help would be appreciated

> btw, this is my first time using tin, so my email addr probably isn't right :)



A possible cause:
Some part of your system setup may be generating malformed system names
initially; when pppd
is up this bad system name is sent off to the name server at your ISP
and it struggles with it
before giving up. Then your system generates an ok system name and/or
your local
name resolver maps the name to a IP address and everybody is happy.
While it sounds
far fetched it actually happened as i was setting up my local network.

A simpler scenario may be sufficient to cause the delay:- the external
nameserver is
queried first for machines on the local network and the external
nameserver does not
know about the local machines. When pppd is not up the external name
server can not
be reached so the local name server will be queried fast; when pppd is
up the external
name server has to time out before the local name server is queried.

Run pppd with debug and watch /var/log/messages.
--
regards,
 Ramesh
(Ramesh Narayanaswamy)

 
 
 

1. multithreaded app scales bad, causes high CPU system load

Hello,
I writing a multithreaded application that at some point wakes up two
threads executing simultaneous calculations on the same datastructure. On
my two processor SMP machine this causes rising CPU load but mostly system
load, the real speedup is almost negligible.
I tried many different data structure setups to find out what causes the
system load instead of better SMP scaling, e.g., assigning a local copy of
the data structure to every thread to avoid a potential memory access
bottle-neck, but I was not able to gain a better scaling.
Does anybody know what a system CPU load in this case means?
Any ideas are welcome!
Regards,
Thorsten

2. IP address for eth0

3. PPPD really this slow?

4. V.35 driver for linux on PPP searching !

5. SCSI Hard Disk Microcode update without using the diskette drive!

6. Ftp connection SunOS <--> 2.0.17 really slow, why?

7. How do I use a hand-held..

8. SENDMAIL 8.7/8.7: Runs REALLY SLOW - Why?

9. ppp cable connection really slow, why?

10. Gnome apps load slow

11. Gnome apps very slow to load under KDE

12. Really, really slow connection to local server via PPP.