# Tear down when done
refuse to admit there are alternatives to RAII
，详情可参考谷歌浏览器【最新下载地址】
Virtual memory is conceptually simple but potentially devastating to performance. Every memory access must go through segmentation (add segment base, check limit) and then paging (look up the page table). Naively, paging alone requires two additional memory reads per access -- one for the page directory entry, one for the page table entry.
Community larder helps 117 people in one day