Re: [LTP] Concurrency-safe patches

[Renaud L. <Ren...@ke...>]

Hi !

> It would be foolish to say that it won´t be of any interest. It is
> definitely very important to make all LTP test cases SMP safe. Thank you
> very much for pointing that out.

Thanks for your interrest !

But I thing there is a little misunderstood.

When talking about SMP safeness, I was not saying that current tests
are not SMP-safe. I mean, the code is correct if you run just one instance of
each test.

But, if you run multiple instances of the same test at the same time, you can
encounter problems. Mainly because of object naming conflicts (with IPCs), 
port
conflicts, etc.

For instance, doing the following is correct :

renaud@leodagan:$ ./sendfile02
sendfile02    1  PASS  :  functionality of sendfile() is correct
sendfile02    2  PASS  :  functionality of sendfile() is correct
sendfile02    3  PASS  :  functionality of sendfile() is correct
sendfile02    4  PASS  :  functionality of sendfile() is correct

But doing the following fails :
renaud@leodagan:$ for i in `seq 1 2`; do ./sendfile02 & done
sendfile02    1  PASS  :  functionality of sendfile() is correct
sendfile02    1  PASS  :  functionality of sendfile() is correct
sendfile02    2  BROK  :  call to bind() failed: Address already in use
sendfile02    3  BROK  :  Remaining cases broken
sendfile02    2  PASS  :  functionality of sendfile() is correct
sendfile02    4  BROK  :  Remaining cases broken
sendfile02    3  PASS  :  functionality of sendfile() is correct
sendfile02    4  PASS  :  functionality of sendfile() is correct

We do this kind of "parallel" executions of the same test to stress kernel
level SMP sensitive code.

So, if this particular issue is of interrest, I can send other patches.

Regards.

R.

-- 
Renaud Lottiaux

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