Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.os.linux.development.system > #609

Re: how to create a interrupt service function in c for real time linux operating system?

Show key headers only | View raw

On Wednesday, 2 April 2014 07:44:03 UTC+2, Tauno Voipio  wrote:
> On 2.4.14 08:21, Hemanth Venkatappa wrote:
> 
> > On Tuesday, 1 April 2014 13:10:45 UTC+2, Tauno Voipio  wrote:
> 
> >> On 1.4.14 11:56, Hemanth Venkatappa wrote:
> 
> >>
> 
> >>> On Thursday, 27 March 2014 16:30:30 UTC+1, Tauno Voipio  wrote:
> 
> >>
> 
> >>>>>> On 26.3.14 10:46, Hemanth Venkatappa wrote:
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>    >
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>    >
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>    > Where to write a interrupt handler and how to register with kernel in
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>> linux?
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>    >
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>    > Scenario : Client is sending a data and the server is receving the
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>> data from
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>    > client via ethernet layer (udp). When the server receives a data from
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>> the client on the ip layer (kernel). It interrupts the kernel and kernel
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>> as to execute the data by the client, so I want to create a interrupt
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>> service function to catch the interrupt from the network service card.
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>    >
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>    > I can't write kernel modules (the kernel is not open) and you have
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>> real-time in
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>    > user-space. However I can write code using RTLinux (real time linux)
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>> in kernel
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>    > space and with kernel modules.
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>> Please explain what you are trying to achieve by catching the network
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>> interface interrupts. It is about the most silly place in the whole
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>> networking stack to catch for doing something allowed and useful.
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>> There are different hook positions in the network protocol stack, but
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>> for most of them, you need to have superuser privileges, for obvious
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>> security reasons.
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>> Doing anything in hardware I/O, including catching interrupts, is also
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>> considered such an activity that it needs superuser privileges.
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>> Your description on the 'openness' is contradictory - either you have
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>> the necessary privileges, or you don't have them.
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>> Try again to describe the ultimate goal of this exercise, so we can
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>> lead you to the correct direction.
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>> --
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>>
> 
> >>
> 
> >>>> -TV
> 
> >>
> 
> >>>
> 
> >>
> 
> >>
> 
> >>
> 
> >> (-- extra long lines truncated -TV --)
> 
> >>
> 
> >>
> 
> >>
> 
> >>> how to get the interrupt time (timestamp) in kernel mode of real time linux?
> 
> >>
> 
> >>>
> 
> >>
> 
> >>> client- server communication - client is sender and server is receiver.
> 
> >>
> 
> >> when the server receives the data on the ethernet interface(UDP) the kernel
> 
> >>
> 
> >>    in the server is triggered. I am using real time LINUX on the server
> 
> >>
> 
> >> side.
> 
> >>
> 
> >> server(i.e embedded pc target) is handling interrupts to trigger the
> 
> >>
> 
> >> embedded
> 
> >>
> 
> >> pc target (conatining rt linux) to gain the attention to execute the newly
> 
> >>
> 
> >> arrived data. I want to calculate the time in kernel as soon as the
> 
> >>
> 
> >> interrupt
> 
> >>
> 
> >> occurs and send the response back to the client.
> 
> >>
> 
> >>
> 
> >>
> 
> >>
> 
> >>
> 
> >> Could someone please help me ??
> 
> >>
> 
> >>
> 
> >>
> 
> >>
> 
> >>
> 
> >> You still did not tell what for you are wanting the times. The response
> 
> >>
> 
> >> gives the necessary boundary conditions for the responses.
> 
> >>
> 
> >>
> 
> >>
> 
> >> Also, I did not understand what computers are in your network
> 
> >>
> 
> >> connection. Two RT Linux machines? Is either a PC?
> 
> >>
> 
> >>
> 
> >>
> 
> >> It seems to me that you have already fixed yourself to the idea of
> 
> >>
> 
> >> timing the network interface interrupts. Do you have access to the
> 
> >>
> 
> >> network drivers and their source code? Do you have the skills needed
> 
> >>
> 
> >> to modify and compile a kernel driver?
> 
> >>
> 
> >>
> 
> >>
> 
> >> If you want to measure the server latency from a request packet to
> 
> >>
> 
> >> the corresponding response packet, IMHO, the simplest method is
> 
> >>
> 
> >> to tap the network connection and grab the interesting traffic
> 
> >>
> 
> >> with Wireshark. It will give the timing without any extra programming.
> 
> >>
> 
> >>
> 
> >>
> 
> >> --
> 
> >>
> 
> >>
> 
> >>
> 
> >> -TV
> 
> >
> 
> > I am calculating the timestamp i.e time when the interrupt occurs and when it starts scheduling. The client is RTPROPC and server is real time linux.
> 
> >
> 
> 
> 
> OK. Let's continue:
> 
> 
> 
> Why are you calculating the timestamp?
> 
> What are you intending to use it for?
> 
> 
> 
> -- 
> 
> 
> 
> -TV

I am calculating the time at which the data arrived from the client on the ethernet layer and the time at which the kernel starts executing. So that I can analyse the latency for the operating system

Back to comp.os.linux.development.system | Previous | Next — Previous in thread | Next in thread | Find similar

Thread

how to create a interrupt service function in c for real time linux operating system? Hemanth Venkatappa <hemanthvenkatappa@gmail.com> - 2014-03-26 01:46 -0700
  Re: how to create a interrupt service function in c for real time linux operating system? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2014-03-26 15:24 +0200
    Re: how to create a interrupt service function in c for real time linux operating system? Hemanth Venkatappa <hemanthvenkatappa@gmail.com> - 2014-03-27 00:25 -0700
      Re: how to create a interrupt service function in c for real time linux operating system? Joe Beanfish <joebeanfish@nospam.duh> - 2014-03-27 13:14 +0000
      Re: how to create a interrupt service function in c for real time linux operating system? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2014-03-27 17:30 +0200
        Re: how to create a interrupt service function in c for real time linux operating system? Hemanth Venkatappa <hemanthvenkatappa@gmail.com> - 2014-04-01 01:56 -0700
          Re: how to create a interrupt service function in c for real time linux operating system? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2014-04-01 14:10 +0300
            Re: how to create a interrupt service function in c for real time linux operating system? Hemanth Venkatappa <hemanthvenkatappa@gmail.com> - 2014-04-01 22:21 -0700
              Re: how to create a interrupt service function in c for real time linux operating system? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2014-04-02 08:44 +0300
                Re: how to create a interrupt service function in c for real time linux operating system? Hemanth Venkatappa <hemanthvenkatappa@gmail.com> - 2014-04-02 05:27 -0700
                Re: how to create a interrupt service function in c for real time linux operating system? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2014-04-02 17:50 +0300
                Re: how to create a interrupt service function in c for real time linux operating system? Hemanth Venkatappa <hemanthvenkatappa@gmail.com> - 2014-04-02 08:46 -0700
                Re: how to create a interrupt service function in c for real time linux operating system? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2014-04-02 21:49 +0300
                Re: how to create a interrupt service function in c for real time linux operating system? Richard Kettlewell <rjk@greenend.org.uk> - 2014-04-02 23:13 +0100
                Re: how to create a interrupt service function in c for real time linux operating system? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2014-04-03 08:59 +0300

csiph-web