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* how can i send real-time signal?
@ 2009-06-05 17:41 wael showair
  2009-06-06 20:51 ` Benedikt Spranger
  2009-06-07  0:33 ` wael showair
  0 siblings, 2 replies; 3+ messages in thread
From: wael showair @ 2009-06-05 17:41 UTC (permalink / raw)
  To: linuxppc-dev


Hi All,
i m using linux-kernel 2.6.27 & a board of MPC8555 processor.
i have also DSP-core on the same board.

My aim is : Each time the DSP-core interrupts the MPC8555 processor, a
process in the user space will be informed by the arrival of this each
interrupt.

So i decided to use sw signals, in the ISR of the DSP-core interrupt i send
a SW signal to the user space process? Is this the best solution? are there
any better suggestion to achieve my aim? 

i used the kernel API send_sig_info because i want to send information with
the sent signal & my signal type was SIGUSR1

i could receive the SW signal successfully but i found out that the standard
SW signals are not queued if they r in the pending queue of the user space
process but the real-time signals do.
so i changed the type of the signal to SIGRTMIN but unfortunately i could
receive any SW signal from my ISR & i noticed that always the second
interrupt causes a kernel panic

so am i using the correct signal type?
am i using the correct kernel API to send a real-time SW signal?

plz help 
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^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: how can i send real-time signal?
  2009-06-05 17:41 how can i send real-time signal? wael showair
@ 2009-06-06 20:51 ` Benedikt Spranger
  2009-06-07  0:33 ` wael showair
  1 sibling, 0 replies; 3+ messages in thread
From: Benedikt Spranger @ 2009-06-06 20:51 UTC (permalink / raw)
  To: linuxppc-dev

Am Fri, 5 Jun 2009 10:41:56 -0700 (PDT)
schrieb wael showair <showair2003@yahoo.com>:

> My aim is : Each time the DSP-core interrupts the MPC8555 processor, a
> process in the user space will be informed by the arrival of this each
> interrupt.
You should have a look at drivers/uio...

> So i decided to use sw signals, in the ISR of the DSP-core interrupt
> i send a SW signal to the user space process? Is this the best
> solution? are there any better suggestion to achieve my aim? 
signals are expensive. Look at the UIO-Framework for a cheaper solution.
preallocated RT-Signals on the other Hand are fragile. Blocking reads
are cheaper and in case of preempt-RT, but not resticted to it, much
easier to handle.

Bene

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: how can i send real-time signal?
  2009-06-05 17:41 how can i send real-time signal? wael showair
  2009-06-06 20:51 ` Benedikt Spranger
@ 2009-06-07  0:33 ` wael showair
  1 sibling, 0 replies; 3+ messages in thread
From: wael showair @ 2009-06-07  0:33 UTC (permalink / raw)
  To: linuxppc-dev


Am Fri, 5 Jun 2009 10:41:56 -0700 (PDT)
schrieb wael showair <showair2003@yahoo.com>:

> My aim is : Each time the DSP-core interrupts the MPC8555 processor, a
> process in the user space will be informed by the arrival of this each
> interrupt.
You should have a look at drivers/uio...

> So i decided to use sw signals, in the ISR of the DSP-core interrupt
> i send a SW signal to the user space process? Is this the best
> solution? are there any better suggestion to achieve my aim? 
signals are expensive. Look at the UIO-Framework for a cheaper solution.
preallocated RT-Signals on the other Hand are fragile. Blocking reads
are cheaper and in case of preempt-RT, but not resticted to it, much
easier to handle.

Bene
-- 
View this message in context: http://www.nabble.com/how-can-i-send-real-time-signal--tp23892580p23906892.html
Sent from the linuxppc-dev mailing list archive at Nabble.com.

^ permalink raw reply	[flat|nested] 3+ messages in thread

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2009-06-05 17:41 how can i send real-time signal? wael showair
2009-06-06 20:51 ` Benedikt Spranger
2009-06-07  0:33 ` wael showair

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