On Tue, 8 Mar 2005, KAMEZAWA Hiroyuki wrote: > Hi, > > Mel Gorman wrote: > > > +#define BITS_PER_ALLOC_TYPE 5 > > #define ALLOC_KERNNORCLM 0 > > #define ALLOC_KERNRCLM 1 > > #define ALLOC_USERRCLM 2 > > #define ALLOC_FALLBACK 3 > > +#define ALLOC_USERZERO 4 > > +#define ALLOC_KERNZERO 5 > > > > Now, 5bits per MAX_ORDER pages. > I think it is simpler to use "char[]" for representing type of memory alloc > type than bitmap. >
Possibly, but it would also use up that bit more space. That map could be condensed to 3 bits but would make it that bit (no pun) more complex and difficult to merge. On the other hand, it would be faster to use a char[] as it would be an array-index lookup to get a pageblock type rather than a number of bit operations. So, it depends on what people know to be better in general because I have not measured it to know for a fact. Is it better to use char[] and use array indexes rather than bit operations or is it better to leave it as a bitmap and condense it later when things have settled down? -- Mel Gorman - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
