On Mon, 1 Dec 2003, Ronald Bultje wrote:
> On Mon, 2003-12-01 at 00:06, Steven M. Schultz wrote:
> > As a temporary measure you can try editing the compat function
> > posix_memalign to return an aligned address. NOTE: this will result
>
> Is this function called often? If not, it can be easily worked around by
> creating a linked list of allocated pointers from posix_memalign().
> Then, return (ret + 3) &~ 3. In posix_memalign_free, check the given
> pointer against each value in the list (listval + 3) &~ 3 and free
>
Well, it'd be either 16 or 64 byte alignment but the same thing
could be done of course.
That is what I suggested Nicolas try as an experiment - adjust the
value returned from the compatibility posix_memalign() function to
see if the problem goes away. That would be the conclusive proof
that the alignment is indeed the cause of the problem.
> If we don't call this too often, this will have no measurable
> performance effects.
It's not the performance issue at all - the function isn't called
often enough to make a difference.
The goal was to allocate memory that could be released by calls
to the standard free() function and not have the calling program
remember which buffers were allocated by posix_memalign() and
which were allocated by malloc()
The encoder shared library will be used outside of mpeg2enc so I
do not think it is reasonable to insist that callers of the
functions in libmpeg2encpp.so have to track which buffers need
posix_memalign_free() and which need free().
At the moment the buffers are not free'd so it does not matter if
the return value from posix_memalign() is suitable for free(). That
will not always be true though so a longer term solution needs to
be found.
Cheers,
Steven Schultz
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