Re: [rtl] Maximum RT-FIFO size and lost data on RT_interrupt

[Nallur Ramesh <nalluri@ladron.cs.nmt.edu>]

The ISA Bus probably can reach that speed but thats not the point here.
You need to process the interrupt fast enough to be ready for the next
interrupt to occur. But I guess 25 us freq interrupt can easily be handled
if you are not doing much in your handler except for pumping the data out.
Check the FIFO and make sure its not overflowing.
As far as the FIFO limit is concerned, I think it depends on kmalloc and
as far as I know kmalloc can allocate upto 128k bytes.

On Tue, 14 Jul 1998, Adolf Ahmad MS wrote:

> Dear Kai,
> 
> Thank you for your good answer.
> But, I used P120 And ISA bus can reach 2 MBps.
> 
> Sincerely yours,
> 
> 
> 
> <adolf@ratelindo.co.id>
> OMC Switching Div
> Wisma Bakrie Lt. 5,
> Jl. HR. Rasuna Said Kav B1
> Jakarta
> Telp. 9101112 ext. 411
> 
> > ----------
> > From: 	Kai Mueller[SMTP:mueller@leo.ifr.ing.tu-bs.de]
> > Sent: 	Tuesday, July 14, 1998 3:38 PM
> > To: 	Adolf Ahmad MS
> > Cc: 	rtl@rtlinux.cs.nmt.edu
> > Subject: 	Re: [rtl] Maximum RT-FIFO size and lost data on
> > RT_interrupt
> > 
> > On Tue, Jul 14, 1998 at 09:16:58AM +0700, Adolf Ahmad MS wrote:
> > > Dear All,
> > > 
> > > I have one experience on implementation RT-Linux by employing
> > Interrupt
> > > Request 7 on EPP/LPT port, and one FIFO with size 8192 bytes. But,
> > some
> > > times there are many data lost, it seem caused by n-th interrupt can
> > not
> > > process by CPU , some times on 200th IRQ, 240th IRQ, 600th IRQ, etc
> > .
> > > For information, the data stream speed is 40 kbytes/s and running on
> > > Pentium 120.
> > > 
> > > *	Why many interrupt are lost on my program RT-Linux ?
> > > *	How many bytes the maximum FIFO on RT-Linux ?
> > > 
> > > 
> > >   
> > > I don't know what is wrong in my code.
> > 
> > I would assume that nothing is wrong with your code.
> > If you have a data rate of 40KBytes/s and every byte
> > causes an interrupt than you have propably reached the
> > limit of performance on your system.
> > 
> > Kai
> > 
> > -- 
> >  Kai P. Mueller
> >  Control Department (Regelungstechnik) | Phone [+49] (531) 391-3835
> >  Technical University Braunschweig     | Fax   [+49] (531) 391-5194
> >  D-38092 Braunschweig                  | Email
> > mueller@ifr.ing.tu-bs.de
> > 
> --- [rtl] ---
> For more information on Real-Time Linux see:
> http://www.rtlinux.org/
> 


--- [rtl] ---
For more information on Real-Time Linux see:
http://www.rtlinux.org/