Re: kernel notification to user space task

Re: kernel notification to user space task

[Pete Zaitcev]

> I want my driver running in kernel to send a notification to this task when
> it detects some event.
> 
> for example..if my driver detects that interface 'eth0' is coming up, it
> should send a indication to user task saying 'network interface eth0 is up'

I think it's kind of FAQ. Have a thread waiting in your driver
with add_wait_queue and schedule(). When awoken, the even thread
can signal the main worker thread or do the job itself.

But first, make sure you are not served better with an
event driven main thread (e.g. open a file descriptor
into your driver, then use select() on it together with
all other of your descriptors).

-- Pete

RE: kernel notification to user space task

[Hari Gadi]

Hi,
You can use signals like the example in the book rubini (see the asynchronous notification section).
http://www.xml.com/ldd/chapter/book/index.html

Be sure to download the examples (especially the "scull" example).
thanks,
Hari.

-----Original Message-----
From: Amol Kumar Lad [mailto:amolk@ishoni.com]
Sent: Friday, March 29, 2002 12:20 PM
To: 'linux-kernel@vger.kernel.org'
Subject: kernel notification to user space task


Hi,
  I have a user task running ...
I want my driver running in kernel to send a notification to this task when
it detects some event.

for example..if my driver detects that interface 'eth0' is coming up, it
should send a indication to user task saying 'network interface eth0 is up'

please cc me..

thanks
Amol

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Re: kernel notification to user space task

[Greg KH]

On Fri, Mar 29, 2002 at 10:50:13PM +0530, Amol Kumar Lad wrote:
> 
> for example..if my driver detects that interface 'eth0' is coming up, it
> should send a indication to user task saying 'network interface eth0 is up'

If this is not just a hypothetical example, this kind of userspace
notification is already present in the kernel.  /sbin/hotplug gets
called when ever any network interface is brought up or down.  See the
documentation at linux-hotplug.sf.net for more information if you're
curious.

thanks,

greg k-h