Forum Post: RE: IPC messageq and cache coherency problem

Ramsey,

The whole buffer has already been invalidated at the top of HeapMemMP_free() before entering GateMP. IPC 3.21.00.07 HeapMemMP.c

line 772:

    /*
     *  Invalidate entire buffer being freed to ensure that stale cache
     *  data in block isn't evicted later
     */
    if (obj->cacheEnabled) {
        Cache_inv(newHeader, size, Cache_Type_ALL, FALSE);
    }

line 870 (added in 3.21.00.07):

       /*
        *  Invalidate entire buffer being freed to ensure that stale cache
        *  data in block isn't evicted later
        */
        Cache_inv(newHeader, size, Cache_Type_ALL, TRUE);  /* B2 */

Now you invalidate the whole buffer twice.

I'm not sure what did you try to fix but I believe the modifications made are wrong.

Please take a look into HeapMemMP.c from our repo (attached). It contains the fixes described in my earlier post.

Dmitry(Please visit the site to view this file)