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[lwip-users] Re: [lwip] Pbuf Pool
From: |
James Roth |
Subject: |
[lwip-users] Re: [lwip] Pbuf Pool |
Date: |
Wed, 08 Jan 2003 22:59:52 -0000 |
Mumtaz Ahmad wrote:
>Hi
>
>I am usiung lwip on trimedia board . I am facing a problem when the ethernet
>interface transfers a buffer to lwip .I am experiencing a data loss as
>POOL_BUFFS are not available all the time . I have tried to change the
>number of POOL Buffers but with no success . Most failures are due to free
>lock problem. I tried to understand it but somehow i ahave been unable to
>understand all this caching mechanism and i donot know why i get pbuff pool
>locked often . Any suggestion in this regard ?
>
>Regards
>Mumtaz Ahmad
> _o
> _< \_
> (_) >(_)
> -------------
>
>
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>
I have seen the pool locked in this case (using a debugger):
1. A pbuf_* function is called. It locks the pool.
2. The pbuf_ function indirectly results in a call to sys_sem_* or
similar.
3. The sem function results in a call to a timeout function.
4. Finally, the timeout function calls a pbuf_* function. The pool
is still locked from step 1.
Does this sound right folks?
From what I can tell, it's not really a problem. When I made my
sys_arch functions more accurate in terms of timing, this happened far
less often.
--
James Roth
Shugyo Design Technologies
http://www.shugyodesign.com/
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