On Thu, Sep 17, 2009 at 11:45 PM, Pei Lin <telent997@xxxxxxxxx> wrote:
Lin,
I am not sure I understand what you mean. I know I might not need to
check for in_interrupt or not. But I still don't understand the you complete
statement.
-Leo.
2009/9/18 Leonidas . <leonidas137@xxxxxxxxx>:
This problem is so weird i think. why u need do this check. And you>
>
> On Thu, Sep 17, 2009 at 9:43 PM, Michael Blizek
> <michi1@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>>
>> Hi!
>>
>> On 17:20 Thu 17 Sep , Leonidas . wrote:
>> > Hi List,
>> >
>> > I am aware of the fact that in interrupt context one should not use
>> > mutexes/semaphore
>> > and should stick to spinlocks.
>>
>> Yes, exactly.
>>
>> > I am developing a module which exposes interfaces which could be called
>> > from
>> > any/all
>> > contexts. And I manipulate complex data structures in my functions.
>> > Being on
>> > safer side
>> > I should stick to spinlocks. But in most of the cases it would not be
>> > needed, meaning my
>> > functions would get called mostly from process contexts, so spinlocks
>> > sounds
>> > wasteful
>> > since my critical sections are long and painful.
>>
>> Is there any way to view your code?
>>
>> 1) Executing long functions in interrupt context is bad, because this
>> introduces latencies into the system. Try to put at least the big
>> functions
>> into a workqueue.
>>
>> 2) You can try to remove the locking outside of this module and make it
>> the
>> responsibility of the module user.
>>
>> -Michi
>> --
>> programing a layer 3+4 network protocol for mesh networks
>> see http://michaelblizek.twilightparadox.com
>>
>
> Michi,
>
> Actually, I have not written any code yet, just pondering over design as of
> now.
> Would start writing only once some of these rough edges are sorted out.
>
> Yes, I should ideally move out the big functions outside ISRs, but issue
> with my
> module is, I would not know from where I am getting called. My module will
> just
> export apis which modules can call from whereever they want, and I cant put
> it
> as a constraint that they should not call from ISRs, my module is going to
> be bit
> like profiling module so a user might actually want to call it from ISR to
> profile it.
>
>
> Can I do following?
> As soon as I enter my functions, I check whether I am running in interupt
> context
> or process context and spwan a tasklet/workqueue if I am in interrupt
> context or proceed in the
> same function if I am in process context. This would make more sense right?
>
design your functions and why not know
the code run in which level ? linux is totally opensouce and
transparent for programmers.
--
> But above point does not solve the locking issue? Does it? And I can't move
> locking outside
> my module and ask user to do so since that might not be possible. I want my
> module to be
> as reentrant as possible without making user do too many things.
>
>
> -Leo.
>
>
>
>
Best Regards
Lin
Lin,
I am not sure I understand what you mean. I know I might not need to
check for in_interrupt or not. But I still don't understand the you complete
statement.
-Leo.
