On 03/09/2018 12:24 AM, Aaron Lu wrote: > + /* > + * We are going to put the page back to the global > + * pool, prefetch its buddy to speed up later access > + * under zone->lock. It is believed the overhead of > + * an additional test and calculating buddy_pfn here > + * can be offset by reduced memory latency later. To > + * avoid excessive prefetching due to large count, only > + * prefetch buddy for the last pcp->batch nr of pages. > + */ > + if (count > pcp->batch) > + continue; > + pfn = page_to_pfn(page); > + buddy_pfn = __find_buddy_pfn(pfn, 0); > + buddy = page + (buddy_pfn - pfn); > + prefetch(buddy);
FWIW, I think this needs to go into a helper function. Is that possible? There's too much logic happening here. Also, 'count' going from batch_size->0 is totally non-obvious from the patch context. It makes this hunk look totally wrong by itself.
