Having linking problems with atomic_inc(), atomic_dec_and_test() in user app, help!

[jaf]

Hi Michael,

>> Also, what does "relocation truncated to fit: R_PPC_REL24
atomic_inc(atomic_t
>> *)" mean?
>
>About as much as 'unresolved external reference'. atomic_inc isn't
defined
>in the scope of your code. Look at the kernel headers; it might be
inside
>#ifdef __KRENEL__ (actually it is).

I see... when I wrote the code using Red Hat, this was not the case.  I
assumed
things would be similar under all Linuxes... apparently a bad
assumption.

>Why do you think you need to use atomic_inc directly instead of some
>pthreads wrapper?

I wasn't able to find a decent equivalent to atomic_t in the pthreads
API.
The closest thing I could see would be to wrap my counter increments/
decrements in a pthread_mutex_t to serialize them, but creating a
separate mutex for each atomic counter seems a bit expensive/
inefficient, considering there may be thousands of such atomic counters
active at once.  Is there some other way to use pthreads to get an
atomic counter?  Or is a pthread_mutex_t really efficient enough to
make a decent atomic counter out of?  Or do I need to redesign how my
application works, because there is no good way to do a cheap, portable
user-land atomic counter under Linux?  :^(

Jeremy

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