On Wed, May 04, 2011 at 11:56:58PM -0500, Amit Kulkarni wrote:
> > The random number is derived from a global, which is incremented by a
> > few bits every time a chunk is needed (with a small optimization if
> > only one free slot is left).
> >
>
> I have no feedback on this diff but a question on random placing in
> another two functions.
>
> In static void unmap()
> for (i = 0; tounmap > 0 && i < mopts.malloc_cache; i++) {
> r = &d->free_regions[(i + offset) & (mopts.malloc_cache -
> 1)];
>
> In static void map()
> for (i = 0; i < mopts.malloc_cache; i++) {
> r = &d->free_regions[(i + offset) & (mopts.malloc_cache -
> 1)];
>
> AFAIK
> malloc_cache = 64
> offset = {0 , 15} interval
> free_regions[MALLOC_MAXCACHE] = 256
>
> the effect of logical 'and' is useless because you are only
> really indexing free_regions from i+15, max of 64+15.
>
> If you want to index free_regions randomly over its full range, maybe you
> should do something else?
malloc_cache is a power of the, so a bitwise and with malloc_cache - 1
is equivalent to modulo malloc_cache.
-Otto
>
> Thanks,
> amit
