[ECOS] High priority thread versus network
Wayne Visser
wvisser@lszpaper.com
Wed May 9 19:13:00 GMT 2007
Thanks for the tips, Robin. You may be shooting in the dark, but I *am*
in the dark! ;-)
You're right, it does look like a stack overflow, but I have assertions
enabled (CYGDBG_USE_ASSERTS) and CYGFUN_KERNEL_THREADS_STACK_CHECKING is
also enabled. I've seen no asserts or panics being raised to date. Are
there other assertions I've missed?
I'm using a separate interrupt stack (size = 4096).
I've gone ahead and increased the size of the NET_THREAD and
NET_FAST_THREAD and am currently re-running the tests.
-- Wayne
Robin Randhawa wrote:
> Hi.
>
> Just some shots in the dark :
>
> 1. Have you enabled all assertions ? Checks for stack manipulation ?
>
> 2. Are you using a separate interrupt stack ?
>
> 3. Does changing the default stack size of the Network Thread make a
> difference in either the exhibited phenomena and/or the time before the
> system hangs up ?
>
> The problem you face seems to be a stack overflow but there really isn't
> sufficient data to state that as a fact.
>
> I would try the above just to reduce some of the possibilities.
>
> Cheers,
> Robin
>
> On Mon, 2007-05-07 at 08:53 -0400, Wayne Visser wrote:
>> Hello all,
>>
>> We're having a problem with an eCos app that has a relatively
>> long-running, high priority thread (runs at priority 2 every 10 ms and
>> takes about 4ms to complete). Under high network loads, the app will
>> crash with no asserts or panics. If the high priority thread is
>> disabled, the app will run fine for days without problem under high net
>> loads. Conversely, without any networking activity, the app runs fine
>> for days.
>>
>> We've stripped this down to a simple test app with two parts (a) the
>> high priority thread basically does nothing but consume CPU time:
>>
>> static void
>> high_thread( cyg_addrword_t arg )
>> {
>> int i, j;
>> cyg_uint16 buf[1024];
>>
>> while (1)
>> {
>> for ( j=0; j<90; ++j )
>> {
>> for ( i=0; i<1024; ++i)
>> buf[i] = rand();
>> }
>>
>> cyg_thread_delay(1);
>> }
>> }
>>
>> and (b) several identical networking threads that do nothing but accept
>> client connections and echo data sent to them.
>>
>> If several clients connect to the eCos app, a crash will occur in as
>> little as a few minutes (but sometimes hours).
>>
>> So my question is this: Are there any known issues in running a high
>> priority thread with a relatively long running time? i.e. this thread
>> is effectively blocking the network threads from running for up to 4ms.
>> Will that create any known problems?
>>
>> Thanks for any feedback.
>>
>> -- Wayne
>>
>>
>> ps: Out target is i386 and the problem is evident with both 8139 and
>> 82559 ethernet drivers. Curiously, the problem does NOT appear with the
>> 83816 ethernet driver.
>>
>>
>
> .
>
--
Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss
More information about the Ecos-discuss
mailing list