{"id":971,"date":"2013-06-04T11:03:51","date_gmt":"2013-06-04T03:03:51","guid":{"rendered":"http:\/\/www.dogeye.net\/?p=971"},"modified":"2013-06-04T11:03:51","modified_gmt":"2013-06-04T03:03:51","slug":"linux%e6%a1%8c%e9%9d%a2%e7%8e%af%e5%a2%83%e4%b8%8b%e5%86%85%e5%ad%98%e5%8e%bb%e9%87%8d%e6%8a%80%e6%9c%af%e7%9a%84%e7%a0%94%e7%a9%b6%e4%b8%8e%e5%ae%9e%e7%8e%b0%e7%ac%ac%e4%ba%8c%e7%ab%a0","status":"publish","type":"post","link":"https:\/\/ykyi.net\/?p=971","title":{"rendered":"Linux\u684c\u9762\u73af\u5883\u4e0b\u5185\u5b58\u53bb\u91cd\u6280\u672f\u7684\u7814\u7a76\u4e0e\u5b9e\u73b0(\u7b2c\u4e8c\u7ae0)"},"content":{"rendered":"

Linux\u684c\u9762\u73af\u5883\u4e0b\u5185\u5b58\u53bb\u91cd\u6280\u672f\u7684\u7814\u7a76\u4e0e\u5b9e\u73b0<\/h1>\n

\u5728\u8fd9\u91cc\u53ef\u4ee5\u4e0b\u8f7d\u539f\u7a3f www.ykyi.net\/upload\/Research_and_Implementation_of_Memory_Deduplication_in_the_Linux_Desktop_Environment.pdf<\/span><\/a><\/strong><\/h1>\n

\u7b2c\u4e8c\u7ae0 \u76f8\u5173\u7406\u8bba\u4e0e\u6280\u672f<\/h1>\n

2.1 \u5185\u5b58\u7ba1\u7406<\/h2>\n

\u5185\u5b58\u7ba1\u7406\u662f\u64cd\u4f5c\u7cfb\u7edf\u5185\u6838\u4e2d\u6781\u4e3a\u91cd\u8981\u7684\u90e8\u5206\uff0c\u5b83\u6d89\u53ca\u7269\u7406\u5730\u5740\u3001\u865a\u62df\u5730\u5740\u3001\u5206\u6bb5\u3001\u5206\u9875\u7b49\u8bf8\u591a\u6982\u5ff5\u3002<\/p>\n

2.1.1 \u5185\u5b58\u5730\u5740<\/h3>\n

\u7a0b\u5e8f\u4f7f\u7528\u5730\u5740\u6765\u8bbf\u95ee\u5185\u5b58\u5355\u5143\u3002\u5bf9\u4e8ex86\u67b6\u6784\u7684\u4e2d\u592e\u5904\u7406\u5668\uff0c\u4f7f\u7528\u903b\u8f91\u5730\u5740\uff0c\u865a\u62df\u5730\u5740\uff0c\u7269\u7406\u5730\u5740\u4e09\u79cd\u4e0d\u540c\u7684\u5730\u5740[15]<\/sup>\u3002<\/p>\n

\u903b\u8f91\u5730\u5740\u5305\u62ec\u6bb5\u548c\u504f\u79fb\u5730\u5740\u4e24\u90e8\u5206\uff0c\u5b83\u4eec\u5171\u540c\u7528\u6765\u6307\u5b9a\u673a\u5668\u6307\u4ee4\u6216\u8005\u64cd\u4f5c\u6570\u5728\u5185\u5b58\u4e2d\u7684\u4f4d\u7f6e\u3002\u903b\u8f91\u5730\u5740\u5bf9\u5e94\u4e0b\u6587\u63d0\u5230\u7684\u5206\u6bb5\u5f0f\u5185\u5b58\u7ba1\u7406\u3002<\/p>\n

\u865a\u62df\u5730\u5740\u4e5f\u88ab\u79f0\u4f5c\u7ebf\u6027\u5730\u5740\uff0c\u5b83\u8868\u793a\u4e00\u4e2a\u5bfb\u5740\u7a7a\u95f4\u3002\u5728Linux\u64cd\u4f5c\u7cfb\u7edf\u4e2d\uff0c\u4f7f\u7528\u4e00\u4e2a\u65e0\u7b26\u53f7\u957f\u6574\u578b\u5b58\u50a8\u865a\u62df\u5730\u5740\u3002\u5982\u679c\u662f\u9488\u5bf932\u4f4dx86\u5904\u7406\u5668\u7684\u5185\u6838\uff0c\u8fd9\u662f\u4e00\u4e2a32\u4f4d\u7684\u65e0\u7b26\u53f7\u957f\u6574\u578b\uff0c\u53ef\u4ee5\u5bfb\u5740\u81f3\u591a232<\/sup>\uff0c\u53734GB\u7a7a\u95f4\u3002\u800cLinux\u5728x86_64\u5904\u7406\u5668\u4e0a\uff0c\u4e00\u4e2a\u65e0\u7b26\u53f7\u957f\u6574\u578b\u670964\u4f4d\uff0c\u4f46\u5b9e\u9645\u4e0a\u53ea\u4f7f\u7528\u4e8648\u4f4d\uff0c\u5373\u53ef\u5bfb\u5740\u5230248<\/sup> \uff0c\u5373256TB\u7684\u5185\u5b58\u7a7a\u95f4\u3002\u5f15\u5165\u865a\u62df\u5730\u5740\u4f7f\u5f97\u7528\u6237\u7a7a\u95f4\u7684\u8fdb\u7a0b\u90fd\u72ec\u81ea\u62e5\u6709\u4e00\u4e2a\u5730\u5740\u7a7a\u95f4\uff0c\u65b9\u4fbf\u64cd\u4f5c\u7cfb\u7edf\u5728\u786c\u4ef6\u7684\u534f\u52a9\u4e0b\u9694\u79bb\u8fdb\u7a0b\u8bbf\u95ee\u5185\u5b58\u7684\u64cd\u4f5c\uff0c\u4ece\u800c\u5b9e\u73b0\u66f4\u9ad8\u7684\u5b89\u5168\u6027\u548c\u4fbf\u6377\u6027\u3002\u572832\u4f4d\u5904\u7406\u5668\u67b6\u6784\u4e0b\uff0c4G\u865a\u62df\u5730\u5740\u7a7a\u95f4\u5212\u5206\u6210\u4e24\u90e8\u5206\uff0c\u9ad8\u7aef\u76841G\u7a7a\u95f4\u88ab\u79f0\u4e4b\u4e3a\u5185\u6838\u7a7a\u95f4\uff0c\u4f4e\u7aef\u76843G\u7a7a\u95f4\u79f0\u4e4b\u4e3a\u7528\u6237\u7a7a\u95f4\u3002\u5185\u6838\u7684\u4ee3\u7801\u548c\u6570\u636e\u5b58\u5728\u5185\u6838\u7a7a\u95f4\uff0c\u7528\u6237\u7a7a\u95f4\u7684\u8fdb\u7a0b\u901a\u8fc7\u7cfb\u7edf\u8c03\u7528\u9677\u5165\u5185\u6838\u7a7a\u95f4\u6267\u884c\u5185\u6838\u7a7a\u95f4\u7684\u4ee3\u7801\u3002\u5bf9\u4e8e64\u4f4d\u5904\u7406\u5668\uff0c\u865a\u62df\u5730\u5740\u540c\u6837\u5206\u4e3a\u5185\u6838\u7a7a\u95f4\u548c\u7528\u6237\u7a7a\u95f4\uff0c\u53ea\u662f\u9488\u5bf964\u4f4d\u5904\u7406\u5668\u7684\u5185\u6838\u62e5\u6709\u5927\u5f97\u591a\u7684\u5bfb\u5740\u8303\u56f4\uff0c\u5bf9\u5185\u6838\u7a7a\u95f4\u548c\u7528\u6237\u7a7a\u95f4\u7684\u5730\u5740\u5212\u5206\u6709\u591a\u79cd\u5b9e\u73b0\u3002<\/p>\n

\u7269\u7406\u5730\u5740\u88ab\u4e2d\u592e\u5904\u7406\u5668\u7528\u6765\u5bfb\u5740\u5185\u5b58\u82af\u7247\u4e0a\u7684\u5b9e\u9645\u7684\u7269\u7406\u5355\u5143\u3002\u5b83\u5bf9\u5e94\u4e86\u9001\u5f80\u5904\u7406\u5668\u7684\u9488\u811a\u4e0a\u7684\u9ad8\u4f4e\u7535\u5e73\u4fe1\u53f7\u3002<\/p>\n

       Linux\u4e2d\u7684\u5185\u5b58\u7ba1\u7406\u5355\u5143 (Memory Management Unit, MMU)\u5728\u786c\u4ef6\u7535\u8def\u7684\u5e2e\u52a9\u4e0b\u628a\u903b\u8f91\u5730\u5740\u8bd1\u6210\u7ebf\u6027\u5730\u5740\uff1b\u800c\u53e6\u4e00\u4e2a\u786c\u4ef6\u7535\u8def\u5219\u5e2e\u52a9\u628a\u7ebf\u6027\u5730\u5740\u7ffb\u8bd1\u6210\u7269\u7406\u5730\u5740\u3002<\/p>\n

2.1.2 \u6bb5\u9875\u5f0f\u5185\u5b58\u7ba1\u7406<\/h3>\n

\u5185\u5b58\u5206\u6bb5\u662f\u753180×86\u5904\u7406\u5668\u5f15\u5165\u7684\u6982\u5ff5\uff0c\u5b83\u9f13\u52b1\u7a0b\u5e8f\u5458\u5728\u8bbe\u8ba1\u7a0b\u5e8f\u65f6\u628a\u7a0b\u5e8f\u4f7f\u7528\u7684\u5185\u5b58\u6309\u7167\u903b\u8f91\u4e0a\u7684\u610f\u4e49\u76f8\u5173\u6027\u5206\u6210\u82e5\u5e72\u4e2a\u90e8\u5206\uff0c\u6bd4\u5982\u6709\u4e9b\u6bb5\u5b58\u653e\u5168\u5c40\u6570\u636e\uff0c\u6709\u4e9b\u6bb5\u5b58\u653e\u7a0b\u5e8f\u4ee3\u7801[16]<\/sup>\u3002<\/p>\n

\u5185\u5b58\u7ba1\u7406\u5355\u5143\u7684\u5206\u9875\u5355\u5143\u534f\u52a9\u628a\u865a\u62df\u5730\u5740\u8bd1\u4e3a\u7269\u7406\u5730\u5740\uff0c\u4e3a\u4e86\u63d0\u9ad8\u7ffb\u8bd1\u7684\u6548\u7387\uff0c\u865a\u62df\u5730\u5740\u88ab\u6309\u7167\u56fa\u5b9a\u957f\u5ea6\u5207\u5206\u6210\u4e00\u4e2a\u4e2a\u5c0f\u5355\u5143\uff0c\u5b83\u4eec\u5219\u88ab\u79f0\u4e4b\u4e3a\u9875\u9762\u3002\u9875\u9762\u53ef\u4ee5\u770b\u6210\u662fMMU\u7ba1\u7406\u5185\u5b58\u7684\u6700\u5c0f\u5355\u4f4d\u3002<\/p>\n

      \u5206\u6bb5\u548c\u5206\u9875\u90fd\u7528\u6765\u5212\u5206\u5185\u5b58\uff0c\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\uff0c\u5b83\u4eec\u7684\u529f\u80fd\u6709\u4e00\u5b9a\u91cd\u5408\u3002\u5b9e\u9645\u4e0a\uff0cLinux\u5185\u6838\u7684\u5185\u5b58\u7ba1\u7406\u673a\u5236\u503e\u5411\u4e8e\u4f7f\u7528\u5206\u9875\u6280\u672f\u3002Linux\u8fdb\u7a0b\u8fd0\u884c\u5728\u7528\u6237\u7a7a\u95f4\u65f6\u4f7f\u7528\u7684\u6807\u5fd7\u4ee3\u7801\u6bb5\u7684\u4ee3\u7801\u6bb5\u9009\u62e9\u5b50(segmentation selector)\u548c\u6570\u636e\u6bb5\u9009\u62e9\u5b50\u662f\u76f8\u7b49\u7684\uff1b\u8fdb\u7a0b\u8fd0\u884c\u5728\u5185\u6838\u7a7a\u95f4\u65f6\u4f7f\u7528\u7684\u4ee3\u7801\u6bb5\u9009\u62e9\u5b50\u548c\u6570\u636e\u6bb5\u9009\u62e9\u5b50\u4e5f\u662f\u76f8\u7b49\u7684\u3002\u800c\u4e14\u8fd9\u56db\u4e2a\u6bb5\u9009\u62e9\u5b50\u7684\u6bb5\u57fa\u5740\u90fd\u8bbe\u7f6e\u4e3a0\u3002\u8fd9\u610f\u5473\u7740\u5728Linux\u64cd\u4f5c\u7cfb\u7edf\u4e2d\uff0c\u65e0\u8bba\u5bfb\u5740\u6570\u636e\u548c\u8fd8\u662f\u5bfb\u5740\u6307\u4ee4\uff0c\u65e0\u8bba\u5728\u7528\u6237\u7a7a\u95f4\u8fd8\u662f\u5185\u6838\u7a7a\u95f4\uff0c\u903b\u8f91\u5730\u5740\u7684\u6bb5\u57fa\u5740\u90e8\u5206\u4e3a0\uff0c\u504f\u79fb\u5730\u5740\u90e8\u5206\u521a\u597d\u7b49\u4e8e\u865a\u62df\u5730\u5740\u3002<\/p>\n

\u5728Linux\u6240\u652f\u6301\u7684\u5927\u591a\u6570\u786c\u4ef6\u5e73\u53f0\u4e0a\uff0c\u9ed8\u8ba4\u7684\u9875\u9762\u5927\u5c0f\u662f4K\u3002\u4f46Linux\u540c\u65f6\u4e5f\u652f\u6301\u5927\u4e8e4K\u7684\u9875\u9762\u7684\u5185\u5b58\u7ba1\u7406\u3002\u8fd0\u884c\u5728\u7528\u6237\u7a7a\u95f4\u7684\u4ee3\u7801\u53ef\u4ee5\u4f7f\u7528glibc\u5e93\u4e2d\u7684getpagesize()\u51fd\u6570\u5f97\u5230\u5f53\u524d\u4f7f\u7528\u7684\u9875\u9762\u5927\u5c0f\u3002\u672c\u8bba\u6587\u53ea\u9488\u5bf9\u5728x86_64\u67b6\u6784\u4e0a\u9875\u9762\u5927\u5c0f\u662f4K\u7684Linux\u5185\u6838\u3002\u5b9e\u9645\u4e0a\u4ece\u5185\u68382.6.38\u5f00\u59cb\uff0c\u5185\u6838\u4e2d\u5f00\u59cb\u652f\u6301\u900f\u660e\u5de8\u9875(Transparent Huge Page)[17]<\/sup>\uff0c\u5185\u6838\u4e2d\u6709\u4e9b\u9875\u9762\u7684\u5927\u5c0f\u5b9e\u9645\u4e0a\u662f2M\uff0c\u4f46\u8fd9\u4e0d\u5f71\u54cd\u6309\u71674K\u7684\u9875\u9762\u5927\u5c0f\u5c55\u5f00\u8ba8\u8bba\u3002<\/p>\n

Linux\u4f7f\u7528\u5206\u7ea7\u9875\u8868\u7684\u65b9\u5f0f\u628a\u865a\u62df\u5730\u5740\u6620\u5c04\u5230\u9875\u9762\u3002\u572832\u4f4d\u5904\u7406\u5668\u4e0a\u4f7f\u7528\u4e8c\u7ea7\u9875\u8868\uff0c\u5728x86_64\u67b6\u6784\u7684\u5904\u7406\u5668\u4e0a\u5219\u4f7f\u7528\u56db\u7ea7\u9875\u8868\u3002<\/p>\n

 <\/p>\n

 <\/p>\n

\u56fe2-1 \u56db\u7ea7\u9875\u8868<\/p>\n

 <\/p>\n

       \u5982\u56fe2-1\u6240\u793a\uff0c\u4ee5\u9488\u5bf9x86_64\u67b6\u6784\u5904\u7406\u5668\u7684Linux\u5185\u6838\u4e3a\u4f8b\uff0c64\u4f4d\u865a\u62df\u5730\u5740\u7684\u9ad816\u4f4d\u4e0d\u88ab\u4f7f\u7528\uff0c\u4f4e48\u4f4d\u88ab\u5e73\u5747\u5206\u4e3a5\u6bb5\uff0coffset\u6bb5\u536012\u4f4d\uff0c\u5176\u5b83\u56db\u4e2a\u6bb5\u5404\u53609\u4f4d\u3002\u8fd9\u4e2a\u5212\u5206\u5728\u6e90\u4ee3\u7801\u6587\u4ef6arch\/x86\/include\/asm\/pgtable_64_types.h\u4e2d\u5b9a\u4e49\u3002cr3\u5bc4\u5b58\u5668\u5b58\u50a8\u4e86\u9875\u5168\u5c40\u76ee\u5f55\u7684\u7269\u7406\u5730\u5740\u3002\u5728\u628a\u865a\u62df\u5730\u5740\u7ffb\u8bd1\u5230\u7269\u7406\u5730\u5740\u7684\u8fc7\u7a0b\u4e2d\uff0cMMU\u5148\u4ececr3\u5bc4\u5b58\u5668\u4e2d\u53d6\u51fa\u5168\u5c40\u76ee\u5f55\u7684\u7269\u7406\u5730\u5740\uff0c\u518d\u52a0\u4e0aGLOBALDIR\u6bb5\u7b97\u51fa\u7684\u504f\u79fb\u91cf\uff0c\u4ece\u800c\u5728\u9875\u5168\u5c40\u76ee\u5f55\u4e2d\u5f97\u5230\u9875\u4e0a\u7ea7\u76ee\u5f55\u7684\u7269\u7406\u5730\u5740\u3002\u4e0e\u6b64\u7c7b\u4f3c\uff0c\u4ece\u9875\u4e0a\u7ea7\u76ee\u5f55\u4e2d\u5f97\u5230\u9875\u4e2d\u95f4\u76ee\u5f55\u7684\u5730\u5740\uff0c\u7136\u540e\u5f97\u5230\u9875\u8868\u7684\u5730\u5740\uff0c\u518d\u5f97\u5230\u9875\u9762\u7684\u5730\u5740\uff0c\u6700\u540e\u7684OFFSET\u5b57\u6bb5\u5219\u5b9a\u4f4d\u5230\u9875\u9762\u4e2d\u7684\u4e00\u4e2a\u5b57\u8282\u3002\u81f3\u6b64\uff0c\u865a\u62df\u5730\u5740\u88ab\u7ffb\u8bd1\u5230\u4e86\u7269\u7406\u5730\u5740\u3002<\/p>\n

\u9875\u5168\u5c40\u76ee\u5f55\uff0c\u9875\u4e0a\u7ea7\u76ee\u5f55\uff0c\u9875\u4e2d\u95f4\u76ee\u5f55\uff0c\u4ee5\u53ca\u9875\u8868\u4e2d\u7684\u6bcf\u4e00\u9879\u90fd\u7531\u76f8\u540c\u7684\u6570\u636e\u7ed3\u6784\u8868\u793a\u3002\u5b83\u8bb0\u8f7d\u4e86\u4e00\u4e9b\u91cd\u8981\u7684\u4fe1\u606f\uff0c\u4e0e\u672c\u8bba\u6587\u76f8\u5173\u7684\u4fe1\u606f\u6709\uff1a\u8be5\u9879\u6307\u5411\u7684\u4e0b\u4e00\u7ea7\u8868\u6216\u8005\u9875\u9762\u662f\u5426\u5b58\u5728\u7684\u6807\u5fd7\uff0c\u5982\u679c\u8bbf\u95ee\u65f6\u4e0d\u5b58\u5728\u5219\u4ea7\u751f\u7f3a\u9875\u4e2d\u65ad\uff0c\u7531do_page_fault\u51fd\u6570\u8d1f\u8d23\u628a\u9875\u9762\u8c03\u5165\u5185\u5b58[18]<\/sup>\uff1b\u4e0b\u4e00\u7ea7\u8868\u6216\u9875\u9762\u7684\u7269\u7406\u5730\u5740\uff1b\u4e0b\u4e00\u7ea7\u8868\u6216\u9875\u9762\u662f\u5426\u53ef\u8bfb\u53ef\u5199\u7684\u6807\u5fd7\uff0c\u5229\u7528\u8be5\u6807\u5fd7\u4f4d\u53ef\u4ee5\u5199\u4fdd\u62a4\u4e00\u4e2a\u9875\u9762\u3002<\/p>\n

Linux\u5185\u6838\u7528\u4e00\u4e2astruct page\u7ed3\u6784\u4f53\u63cf\u8ff0\u4e00\u4e2a\u9875\u9762\u7684\u4fe1\u606f\u3002\u8fd9\u4e2a\u7ed3\u6784\u4f53\u5b9a\u4e49\u5728include\/linux\/mm_types.h\u6587\u4ef6\u4e2d[19]<\/sup>\u3002\u56fe2-2\u5217\u51fa\u8fd9\u4e2a\u7ed3\u6784\u4f53\u4e2d\u4e0e\u672c\u8bba\u6587\u76f4\u63a5\u76f8\u5173\u7684\u5b57\u6bb5\u3002<\/p>\n

 <\/p>\n

\u56fe2-2 struct page\u7684\u90e8\u5206\u5b57\u6bb5<\/p>\n

 <\/p>\n

\u5176\u4e2d\u7684flags\u5b57\u6bb5\u5b58\u50a8\u4e86\u9875\u9762\u7684\u72b6\u6001\u4fe1\u606f\uff0c\u4f8b\u5982\uff1a\u8868\u793a\u9875\u9762\u521a\u88ab\u5199\u4e86\u6570\u636e\u7684\u810f\u4f4d\uff1b\u8be5\u9875\u9762\u662f\u5426\u88ab\u9501\u5b9a\u5728\u5185\u5b58\u4e2d\u4e0d\u5145\u8bb8\u7f6e\u6362\u5230\u4ea4\u6362\u5206\u533a\u7684\u6807\u5fd7\u3002_count\u5b57\u6bb5\u548c_mapcount\u5b57\u6bb5\u90fd\u662f\u5f15\u7528\u8ba1\u6570\uff0c\u5b83\u4eec\u7528\u6765\u5171\u540c\u7ef4\u62a4page\u9875\u9762\u7684\u751f\u547d\u671f\u3002_mapcount\u8868\u793a\u4e00\u4e2a\u9875\u9762\u62e5\u6709\u591a\u5c11\u9875\u8868\u9879\u6307\u5411\u5b83\uff0c_count\u88ab\u79f0\u4e3apage\u7684\u4f7f\u7528\u8ba1\u6570\uff0c\u6240\u6709\u7684_mapcount\u8ba1\u6570\u53ea\u76f8\u5f53\u4e8e_count\u8ba1\u6570\u4e2d\u7684\u4e00\u6b21\u8ba1\u6570\u3002\u5982\u679c\u5185\u6838\u4ee3\u7801\u4e2d\u67d0\u6267\u884c\u5e8f\u5217\u5728\u8bbf\u95ee\u67d0\u4e2a\u9875\u9762\u65f6\u9700\u8981\u786e\u4fdd\u8be5\u9875\u9762\u5b58\u5728\uff0c\u5219\u5728\u8bbf\u95ee\u524d\u7ed9_count\u8ba1\u6570\u52a0\u4e00\uff0c\u8bbf\u95ee\u7ed3\u675f\u540e_count\u8ba1\u6570\u51cf\u4e00\u3002\u5f53_count\u8ba1\u6570\u51cf\u5230\u8d1f\u6570\u65f6\u8868\u793a\u6ca1\u6709\u4efb\u4f55\u5185\u6838\u9700\u8981\u4f7f\u7528\u8be5\u9875\u9762\uff0c\u5219\u8868\u793a\u8be5\u9875\u9762\u6ca1\u88ab\u4f7f\u7528\u3002\u5185\u6838\u4ee3\u7801\u4e0d\u5e94\u8be5\u76f4\u63a5\u8bbf\u95ee_count\u8ba1\u6570\uff0c\u800c\u5e94\u8be5\u4f7f\u7528page_count\u51fd\u6570\u3002\u8be5\u51fd\u6570\u7528\u4e00\u4e2astruct page\u7684\u6307\u9488\u505a\u4e3a\u53c2\u6570\uff0c\u5f53\u8be5\u9875\u7a7a\u95f2\u65f6\u51fd\u6570\u8fd4\u56de0\uff0c\u5426\u5219\u8fd4\u56de\u4e00\u4e2a\u6b63\u6570\u8868\u793a\u53c2\u6570\u6307\u5411\u7684\u9875\u9762\u6b63\u88ab\u4f7f\u7528\u3002\u5f53\u9875\u9762\u88ab\u9875\u9ad8\u901f\u7f13\u51b2\u4f7f\u7528\u65f6\uff0cmapping\u57df\u6307\u5411\u4e00\u4e2aaddress_space\u5bf9\u8c61\uff0c\u8be5\u5bf9\u8c61\u4e0eLinux\u6587\u4ef6\u7cfb\u7edf\u4e2d\u7684\u6587\u4ef6\u662f\u4e00\u5bf9\u4e00\u6620\u5c04\u7684\u5173\u7cfb\uff0c\u63cf\u8ff0\u4e86\u4e00\u4e2a\u6587\u4ef6\u5206\u914d\u5230\u7684\u7269\u7406\u9875\u9762\u53ca\u76f8\u5173\u6570\u636e\u7ed3\u6784\u3002\u5982\u679c\u9875\u9762\u5e76\u4e0d\u88ab\u9875\u9ad8\u901f\u7f13\u51b2\u4f7f\u7528\u65f6\uff0cmapping\u5219\u6709\u5176\u5b83\u7684\u610f\u4e49\uff0c\u6bd4\u5982mapping\u5b57\u6bb5\u7684\u6700\u4f4e\u4f4d\u8bb0\u8f7d\u8fd9\u662f\u5426\u662f\u4e00\u4e2a\u533f\u540d\u9875\u9762\u3002virtual\u5b57\u6bb5\u662f\u6620\u5c04\u5230\u8be5\u9875\u9762\u7684\u5185\u6838\u7a7a\u95f4\u7684\u865a\u62df\u5730\u5740\uff0c\u5982\u679c\u8be5\u9875\u9762\u662f\u5c5e\u4e8e\u9ad8\u7aef\u5185\u5b58\u533a\u57df\u5219virtual\u5b57\u6bb5\u4e3aNULL\u3002\u5bf9\u4e8ex86_64\u67b6\u6784\u4e0a\u7684Linux\u5185\u6838\uff0c\u5df2\u7ecf\u6ca1\u6709\u9ad8\u7aef\u5185\u5b58\uff0c\u56e0\u6b64\u8be5\u5b57\u6bb5\u4e0d\u4f1a\u4e3aNULL\u3002<\/p>\n

2.1.3 \u5185\u6838\u4e2d\u7684\u5de8\u9875<\/h3>\n

\u73b0\u4ee3\u5904\u7406\u5668\u7684\u5185\u5b58\u7ba1\u7406\u5355\u5143\u51e0\u4e4e\u90fd\u80fd\u5904\u7406\u96644KB\u5927\u5c0f\u5916\u7684\u591a\u79cd\u9875\u9762\u5c3a\u5bf8\u3002\u7136\u800c\uff0cLinux\u5185\u6838\u5728\u51e0\u4e4e\u6240\u4ee5\u5e73\u53f0\u4e0a\u7684\u5b9e\u73b0\u90fd\u9009\u7528\u6700\u5c0f\u7684\u9875\u9762\u5927\u5c0f\uff0c\u53734KB\uff0c\u6bd44KB\u66f4\u5927\u7684\u9875\u9762\uff0c\u90fd\u88ab\u79f0\u4e4b\u4e3a\u5de8\u9875(huge page)\u3002\u5728\u67d0\u4e9b\u5de5\u4f5c\u73af\u5883\u4e0b\uff0c\u5de8\u9875\u53ef\u4ee5\u7ed9\u64cd\u4f5c\u7cfb\u7edf\u5e26\u6765\u6027\u80fd\u4e0a\u7684\u63d0\u9ad8\u3002\u5de8\u9875\u80fd\u63d0\u9ad8\u64cd\u4f5c\u7cfb\u7edf\u7684\u6027\u80fd\u4e3b\u8981\u662f\u56e0\u4e3a\u4e24\u70b9\u3002\u7b2c\u4e00\uff0c\u4f7f\u7528\u5de8\u9875\u53ef\u4ee5\u51cf\u5c11\u53d1\u751f\u9875\u9762\u51fa\u9519\u5904\u7406\u7684\u9891\u7387\uff0c\u56e0\u4e3a\u5728\u6bcf\u6b21\u9875\u9762\u51fa\u9519\u5904\u7406\u65f6\u5185\u6838\u8c03\u5165\u6bd4\u4f7f\u7528\u5c0f\u9875\u9762\u66f4\u591a\u7684\u5185\u5b58\u3002\u7b2c\u4e8c\uff0c\u4f7f\u7528\u5de8\u9875\u51cf\u5c11\u7ffb\u8bd1\u865a\u62df\u5730\u5740\u7684\u65f6\u95f4\u3002\u5728x86_64\u52a0\u6784\u7684\u5904\u7406\u5668\u4e0a\uff0c\u4ece\u865a\u62df\u5730\u5740\u7ffb\u8bd1\u5230\u7269\u7406\u5730\u7406\u9700\u8981\u4f9d\u6b21\u8bbf\u95ee\u56db\u7ea7\u9875\u8868\uff0c\u975e\u5e38\u8017\u65f6\u3002\u800c\u4f7f\u7528\u5de8\u9875\u53ef\u4ee5\u51cf\u5c11\u9875\u8868\u7684\u7ea7\u6570\u3002\u5b9e\u9645\u4e0a\u66f4\u5927\u7684\u6027\u80fd\u63d0\u9ad8\u6e90\u81ea\u4f7f\u7528\u5de8\u9875\u540e\u63d0\u9ad8\u4e86\u65c1\u8def\u8f6c\u6362\u7f13\u51b2\u533a(Translation Lookaside Buffer\uff0cTLB)\u7684\u547d\u4e2d\u6548\u7387[20]<\/sup>\u3002<\/p>\n

\u5728\u5185\u68382.6.38\u7248\u672c\u4e4b\u524d\uff0c\u552f\u4e00\u4f7f\u7528\u5de8\u9875\u7684\u65b9\u5f0f\u662f\u901a\u8fc7\u975e\u5e38\u590d\u6742\u7684hugetlbfs\u6587\u4ef6\u7cfb\u7edf\u3002\u5e94\u7528\u7a0b\u5e8f\u5f00\u53d1\u8005\u548c\u7cfb\u7edf\u7ba1\u7406\u5458\u90fd\u9700\u8981\u6ce8\u610f\u4e00\u4e9b\u7279\u522b\u4e8b\u9879\u624d\u80fd\u591f\u5f00\u542f\u5de8\u9875\u529f\u80fd\u3002\u56e0\u6b64\u53ea\u6709\u6781\u5c11\u6570\u771f\u6b63\u9700\u8981\u5de8\u9875\u5e26\u6765\u6027\u80fd\u63d0\u9ad8\u7684\u7528\u6237\uff0c\u5982\u4e13\u7528\u6570\u636e\u5e93\u7cfb\u7edf\uff0c\u624d\u4f7f\u7528\u5de8\u9875\u3002<\/p>\n

\u60c5\u51b5\u4ece\u5185\u6838\u7248\u672c2.6.38\u4ee5\u540e\u53d1\u751f\u4e86\u53d8\u5316\uff0c\u4e00\u4e2a\u88ab\u79f0\u4e4b\u4e3a\u900f\u660e\u5de8\u9875\u7684\u529f\u80fd\u88ab\u5408\u5e76\u8fdb\u4e86\u5185\u6838\u4e3b\u5e72\u4ee3\u7801\u3002\u4e4b\u524d\u5185\u6838\u5728VMA\uff08Virtual Memory Area\uff0c\u865a\u62df\u5185\u5b58\u533a\u57df\uff09\u4e2d\u7684\u6240\u6709\u9875\u9762\u5927\u5c0f\u90fd\u662f\u4e00\u6837\u5927\u7684\uff0c\u800c\u52a0\u5165\u900f\u660e\u5de8\u9875\u540e\uff0cVMA\u4e2d\u7684\u9875\u9762\u7684\u5927\u5c0f\u53ef\u80fd\u4e0d\u53ea\u4e00\u79cd\u3002\u900f\u660e\u5de8\u9875\u7684\u5b9e\u73b0\u4ee3\u7801\u6539\u5199\u4e86\u9875\u9762\u51fa\u9519\u5904\u7406\u51fd\u6570\uff0c\u5f53\u4e00\u4e2a\u51fa\u9519\u53d1\u751f\u65f6\uff0c\u5185\u6838\u5c3d\u529b\u5206\u914d\u4e00\u4e2a\u5de8\u9875\uff0c\u5982\u679c\u6210\u529f\u7684\u8bdd\uff0c\u5176\u5b83\u76f8\u5e94\u7684\u5728\u5de8\u9875\u5730\u5740\u8303\u56f4\u5185\u7684\u5c0f\u9875\u9762\u5c31\u4f1a\u88ab\u91ca\u653e\uff0c\u5de8\u9875\u88ab\u63d2\u5165\u5230VMA\u4e2d\u3002\u5982\u679c\u4e0d\u80fd\u5206\u914d\u5230\u4e00\u4e2a\u5de8\u9875\uff0c\u5219\u4ecd\u7136\u6309\u7167\u4ee5\u524d\u7684\u65b9\u5f0f\u5206\u914d\u4e00\u4e2a\u5c0f\u9875\u9762\u3002\u5f53\u5de8\u9875\u9700\u8981\u88ab\u7f6e\u6362\u5230\u4ea4\u6362\u5206\u533a\u65f6\uff0c\u900f\u660e\u5de8\u9875\u673a\u5236\u7b80\u5355\u5730\u628a\u5de8\u9875\u5207\u5272\u6210\u5c0f\u9875\u9762\uff0c\u5176\u5b83\u903b\u8f91\u548c\u5904\u7406\u5c0f\u9875\u9762\u65f6\u4e00\u6837\u3002\u5b9e\u9645\u4e0a\u4e0d\u4ec5\u5728\u7f6e\u6362\u5230\u4ea4\u6362\u5206\u533a\u65f6\u9700\u8981\u5207\u5272\u5de8\u9875\uff0c\u5f88\u591a\u5176\u5b83\u7684\u64cd\u4f5c\uff0c\u5982mprotect()\u548cmlock()\u9875\u9762\u65f6\u4e5f\u9700\u8981\u3002\u672c\u8bba\u6587\u5c06\u8be6\u8ff0\u7684KSM\u5728\u5408\u5e76\u9875\u9762\u65f6\u540c\u6837\u9700\u8981\u628a\u5de8\u9875\u5207\u5272\u6210\u5c0f\u9875\u9762\u3002<\/p>\n

\u900f\u660e\u5de8\u9875\u8fd9\u79cd\u8f7b\u4fbf\u5730\u5229\u7528\u5de8\u9875\u7684\u65b9\u5f0f\u4f7f\u5f97\u5f88\u591a\u5185\u6838\u4ee3\u7801\u5e76\u6ca1\u6709\u611f\u77e5\u5230\u5de8\u9875\u7684\u5b58\u5728\uff0c\u5bf9\u4e8e\u5e94\u7528\u7a0b\u5e8f\u5219\u66f4\u6ca1\u6709\u611f\u77e5\u5230\u5de8\u9875\uff0c\u56e0\u6b64\u88ab\u79f0\u4e4b\u4e3a\u900f\u660e\u5de8\u9875\u3002<\/p>\n

2.1.4 \u5185\u5b58\u63cf\u8ff0\u7b26<\/h3>\n

Linux\u5185\u6838\u4f7f\u7528\u4e00\u4e2a\u53eb\u5185\u5b58\u63cf\u8ff0\u7b26(Memory Descriptor)\u7684\u7ed3\u6784\u4f53\u63cf\u8ff0\u6bcf\u4e00\u4e2a\u8fdb\u7a0b\u7684\u5730\u5740\u7a7a\u95f4[21]<\/sup>\u3002\u8fd9\u4e2a\u7ed3\u6784\u4f53\u5305\u62ec\u4e86\u6240\u6709\u548c\u8fdb\u7a0b\u5730\u5740\u7a7a\u95f4\u76f8\u5173\u7684\u4fe1\u606f\u3002\u5185\u5b58\u63cf\u8ff0\u7b26\u548cstruct page\u4e00\u6837\u5728\u6587\u4ef6include\/linux\/mm_types.h\u4e2d\u5b9a\u4e49\u3002\u56fe2-3\u5217\u51fa\u8fd9\u4e2a\u7ed3\u6784\u4f53\u4e2d\u4e0e\u672c\u8bba\u6587\u76f4\u63a5\u76f8\u5173\u7684\u5b57\u6bb5\u3002<\/p>\n

 <\/p>\n

 <\/p>\n

\u56fe2-3 struct mm_struct\u7684\u90e8\u5206\u5b57\u6bb5<\/p>\n

 <\/p>\n

\u5176\u4e2d\uff0cmmap\u5b57\u6bb5\u662f\u7528\u6765\u5b9e\u73b0\u4e00\u4e2a\u94fe\u8868\u3002\u8fd9\u4e2a\u94fe\u8868\u94fe\u63a5\u4e86\u5c5e\u4e8e\u8fd9\u4e2a\u5185\u5b58\u63cf\u8ff0\u7b26\u7684\u6240\u6709vm_area_struct\u7ed3\u6784\u4f53\u3002vm_area_struct\u7ed3\u6784\u4f53\u63cf\u8ff0\u4e86\u4e00\u4e2a\u5185\u5b58\u533a\u57df\u3002\u7531\u4e8e\u5c5e\u4e8e\u4e00\u4e2a\u5185\u5b58\u63cf\u8ff0\u7b26\u7684\u5185\u5b58\u533a\u57df\u53ef\u80fd\u975e\u5e38\u591a\uff0c\u4e3a\u4e86\u52a0\u5feb\u5185\u5b58\u533a\u57df\u7684\u67e5\u627e\u4ee5\u53ca\u6dfb\u52a0\u5220\u9664\u7b49\u64cd\u4f5c\u7684\u901f\u5ea6\uff0c\u5185\u6838\u7528mm_rb\u8868\u793a\u4e00\u68f5\u94fe\u63a5\u4e86\u6240\u6709\u5185\u5b58\u533a\u57df\u7684\u7ea2\u9ed1\u6811\u3002\u7ea2\u9ed1\u6811\u662f\u4e00\u79cd\u4e8c\u53c9\u6811\uff0c\u5b83\u88ab\u5e7f\u6cdb\u5730\u5e94\u7528\u5728Linux\u5185\u6838\u4ee3\u7801\u4e2d\u3002mmap\u548cmm_rb\u662f\u7528\u4e24\u79cd\u4e0d\u540c\u7684\u6570\u636e\u7ed3\u6784\u8868\u793a\u540c\u4e00\u6279\u6570\u636e\u3002mm_users\u548cmm_count\u662f\u5185\u5b58\u63cf\u8ff0\u7b26\u7684\u5f15\u7528\u8ba1\u6570\uff0c\u5b83\u7684\u5b9e\u73b0\u539f\u7406\u548cstruct page\u7684\u5f15\u7528\u8ba1\u6570\u7684\u539f\u7406\u4e00\u6837\u3002\u6bcf\u4e00\u4e2a\u8fdb\u7a0b\u5982\u679c\u62e5\u6709\u4e00\u4e2a\u5185\u5b58\u63cf\u8ff0\u7b26\uff0c\u5219\u4f1a\u589e\u52a0mm_users\u7684\u8ba1\u6570\uff0c\u6240\u6709mm_users\u7684\u8ba1\u6570\u53ea\u76f8\u5f53\u4e8emm_count\u7684\u4e00\u4e2a\u8ba1\u6570\u3002\u6bd4\u5982n\u4e2aLinux\u7ebf\u7a0b\u5171\u4eab\u540c\u4e00\u4e2a\u5185\u5b58\u63cf\u8ff0\u7b26\uff0c\u90a3\u4e48\u5bf9\u5e94\u7684\u5185\u5b58\u63cf\u8ff0\u7b26\u7684mm_users\u8ba1\u6570\u5219\u4e3an\uff0c\u800cmm_count\u5219\u53ef\u80fd\u53ea\u662f1\u3002\u5982\u679c\u6709\u5185\u6838\u6267\u884c\u5e8f\u5217\u60f3\u8981\u8bbf\u95ee\u4e00\u4e2a\u5185\u5b58\u63cf\u8ff0\u7b26\uff0c\u5219\u8be5\u6267\u884c\u5e8f\u5217\u5148\u589e\u52a0mm_count\u7684\u8ba1\u6570\uff0c\u4f7f\u7528\u7ed3\u675f\u540e\u51cf\u5c11mm_count\u7684\u8ba1\u6570\u3002\u4e00\u4f46mm_count\u51cf\u4e3a0\uff0c\u8868\u793a\u8be5\u5185\u5b58\u63cf\u8ff0\u7b26\u6ca1\u6709\u4efb\u4f55\u5f15\u7528\uff0c\u5219\u5b83\u4f1a\u88ab\u5185\u6838\u9500\u6bc1\u3002mmap_sem\u662f\u4e00\u4e2a\u8bfb\u5199\u9501\uff0c\u51e1\u662f\u9700\u8981\u64cd\u4f5c\u5185\u5b58\u63cf\u8ff0\u7b26\u4e2d\u7684\u5185\u5b58\u533a\u57df\u65f6\uff0c\u5219\u9700\u8981\u5148\u5f97\u5230\u76f8\u5e94\u7684\u8bfb\u9501\u6216\u8005\u5199\u9501\uff0c\u4f7f\u7528\u7ed3\u675f\u540e\u91ca\u653e\u8be5\u9501\u3002mm_list\u5b57\u6bb5\u662f\u4e00\u4e2a\u5faa\u73af\u53cc\u94fe\u8868\u3002\u5b83\u94fe\u63a5\u4e86\u7cfb\u7edf\u4e2d\u6240\u6709\u7684\u5185\u5b58\u63cf\u8ff0\u7b26\u3002flags\u5b57\u6bb5\u5b9a\u4e49\u4e86\u5185\u5b58\u63cf\u8ff0\u7b26\u7684\u6807\u5fd7\uff0c\u8fd9\u4e9b\u6807\u5fd7\u6807\u8bb0\u4e86\u5185\u5b58\u63cf\u8ff0\u7b26\u7684\u4e00\u4e9b\u72b6\u6001\u548c\u5c5e\u6027\uff0c\u5185\u6838\u4ee3\u7801\u9700\u8981\u4f7f\u7528\u539f\u5b50\u64cd\u4f5c\u8bbf\u95ee\u8be5\u5b57\u6bb5\u3002<\/p>\n

2.1.5 \u865a\u62df\u5185\u5b58\u533a\u57df<\/h3>\n

\u540c\u6837\u88ab\u5b9a\u4e49\u5728inlude\/linux\/mm_types.h\u4e2d\u7684\u7ed3\u6784\u4f53vm_area_struct\u7528\u6765\u63cf\u8ff0\u4e00\u4e2a\u5185\u5b58\u533a\u57df\u3002\u5728Linux\u5185\u6838\u4e2d\uff0c\u5185\u5b58\u533a\u57df\u7ecf\u5e38\u88ab\u79f0\u4e4b\u4e3a\u865a\u62df\u5185\u5b58\u533a\u57df(Virtual Memory Areas,VMA)\u3002VMA\u63cf\u8ff0\u7684\u5185\u5b58\u533a\u57df\u662f\u4e00\u4e2a\u5730\u5740\u7a7a\u95f4\u4e2d\u7684\u5730\u5740\u8fde\u7eed\u7684\u90e8\u5206\u3002\u800c\u4e14\u8be5\u90e8\u5206\u62e5\u6709\u4e00\u4e9b\u7279\u5b9a\u7684\u5c5e\u6027\uff0c\u6bd4\u5982\u8bbf\u95ee\u6743\u9650\u548c\u76f8\u5173\u8054\u7684\u64cd\u4f5c\u7b49\u3002\u4e0d\u540c\u7684VMA\u53ef\u4ee5\u7528\u6765\u63cf\u8ff0\u4e0d\u540c\u7684\u5185\u5b58\u533a\u57df\u3002\u6bd4\u5982\uff0c\u6620\u5c04\u5230\u5185\u5b58\u7684\u6587\u4ef6\uff0c\u7528\u6237\u7a7a\u95f4\u7684\u6808\uff0c\u7279\u522b\u662f\u672c\u8bba\u6587\u91cd\u70b9\u5173\u6ce8\u7684\u533f\u540d\u5185\u5b58\u533a\u57df(Anonymous VMA)\u3002\u4e0b\u9762\u8ba8\u8bba\u672c\u8bba\u6587\u5173\u5fc3\u7684vm_area_struct\u7684\u4e00\u4e9b\u91cd\u8981\u5b57\u6bb5\uff0c\u8fd9\u4e9b\u5b57\u6bb5\u5982\u56fe2-4\u6240\u793a\u3002<\/p>\n

 <\/p>\n

\u56fe2-4 struct vm_area_struct\u7684\u90e8\u5206\u5b57\u6bb5<\/p>\n

 <\/p>\n

vm_mm\u5b57\u6bb5\u6307\u5411\u8be5VMA\u5c5e\u4e8e\u7684\u5185\u5b58\u63cf\u8ff0\u7b26\u3002vm_start\u548cvm_end\u5b57\u6bb5\u8868\u793a\u8be5VMA\u63cf\u8ff0\u7684\u5185\u5b58\u533a\u57df\u7684\u8d77\u59cb\u548c\u7ec8\u70b9\u865a\u62df\u5730\u5740\uff0c\u4f46\u4e0d\u5305\u62ecvm_end\u6307\u5411\u7684\u5730\u5740\uff0c\u5373vm_end\u662f\u865a\u62df\u5185\u5b58\u533a\u57df\u7684\u6700\u540e\u4e00\u4e2a\u6709\u6548\u5b57\u8282\u7684\u540e\u4e00\u4e2a\u5b57\u8282\u3002vm_next\u548cvm_rb\u5206\u522b\u628a\u5185\u5b58\u63cf\u8ff0\u7b26\u62e5\u6709\u7684\u5185\u5b58\u533a\u57df\u7528\u94fe\u8868\uff0c\u548c\u7ea2\u9ed1\u6811\u94fe\u63a5\u8d77\u6765\u3002vm_flags\u8868\u793a\u5185\u5b58\u533a\u57df\u7684\u5c5e\u6027\u3002anon_vma\u4e0e\u5185\u6838\u7684\u9875\u9762\u56de\u6536\u673a\u5236\u56de\u6536\u533f\u540d\u9875\u65f6\u7528\u5230\u7684\u9875\u9762\u53cd\u5c04\u8868\u6709\u5173\u3002vm_file\u662f\u8be5\u5185\u5b58\u533a\u57df\u5bf9\u5e94\u7684\u6587\u4ef6\uff0c\u5982\u679c\u5185\u5b58\u533a\u57df\u662f\u533f\u540d\u7684\uff0c\u5219\u8be5\u5b57\u6bb5\u88ab\u7f6e\u4e3aNULL\u3002<\/p>\n

2.1.6 Slab\u5c42<\/h3>\n

\u9891\u7e41\u5730\u7533\u8bf7\u548c\u56de\u6536\u540c\u4e00\u7c7b\u578b\u7684\u6570\u636e\u7ed3\u6784\u662f\u5185\u6838\u4e2d\u6781\u4e3a\u5e38\u89c1\u7684\u64cd\u4f5c\u3002\u4e3a\u4e86\u63d0\u9ad8\u7533\u8bf7\u548c\u56de\u6536\u67d0\u79cd\u7279\u5b9a\u6570\u636e\u7ed3\u6784\u7684\u6548\u7387\u3002Linux\u5185\u6838\u4e2d\u5f15\u5165\u4e86slab\u5c42\u7684\u6982\u5ff5\uff0c\u901a\u8fc7slab\u5c42\u6765\u7ba1\u7406\u67d0\u79cd\u6570\u636e\u7ed3\u6784\u7684\u9891\u7e41\u7533\u8bf7\u548c\u56de\u6536[22]<\/sup>\u3002<\/p>\n

Slab\u5c42\u628a\u4e0d\u540c\u7684\u6570\u636e\u7ed3\u6784\u5212\u5206\u5230\u4e0d\u540c\u7684\u9ad8\u901f\u7f13\u5b58(cache)\u4e2d\uff0c\u6bcf\u4e2a\u7f13\u5b58\u90fd\u7528\u6765\u7ef4\u62a4\u67d0\u79cd\u6570\u636e\u7ed3\u6784\u7684\u7533\u8bf7\u7684\u56de\u6536\u3002\u6bd4\u5982\uff0c\u4ece\u7ef4\u62a4\u8fdb\u7a0b\u63cf\u8ff0\u7b26\u7684\u7f13\u5b58\u4e2d\u7533\u8bf7\u8fdb\u7a0b\u63cf\u8ff0\u7b26\u65f6\uff0c\u7f13\u5b58\u628a\u4e00\u4e2a\u6807\u8bb0\u4e3a\u53ef\u7528\u7684\u8fdb\u7a0b\u63cf\u8ff0\u7b26\u8fd4\u56de\u7ed9\u8c03\u7528\u8005\uff0c\u540c\u65f6\u628a\u8be5\u63cf\u8ff0\u7b26\u6807\u8bb0\u4e3a\u5df2\u7528\uff1b\u91ca\u653e\u8fdb\u7a0b\u63cf\u8ff0\u7b26\u5219\u4f7f\u5f97\u8fd9\u4e2a\u8fdb\u7a0b\u63cf\u8ff0\u7b26\u5728\u5b58\u653e\u5b83\u7684\u7f13\u5b58\u4e2d\u53c8\u88ab\u6807\u8bb0\u4e3a\u53ef\u7528\u3002<\/p>\n

      \u6bcf\u4e2a\u7f13\u5b58\u88ab\u5212\u5206\u4e3a\u597d\u51e0\u4e2aslab\uff0c\u8fd9\u5c31\u662f\u8fd9\u4e2a\u5b50\u7cfb\u7edf\u88ab\u79f0\u4e4b\u4e3aslab\u5c42\u7684\u539f\u56e0\u3002\u6bcf\u4e2aslab\u662f\u4e00\u9875\u6216\u51e0\u9875\u8fde\u7eed\u7684\u5185\u5b58\u3002\u7f13\u5b58\u7ef4\u62a4\u7684\u67d0\u79cd\u6570\u636e\u7ed3\u6784\uff0c\u79f0\u4e4b\u4e3a\u5bf9\u8c61\uff0c\u5c31\u5168\u90e8\u653e\u5728slab\u4e2d\u3002\u6bcf\u4e2aslab\u5904\u4e8e\u6ee1\uff0c\u90e8\u5206\u6ee1\u6216\u7a7a\u4e09\u79cd\u72b6\u6001\u3002\u5f53slab \u5904\u4e8e\u6ee1\u72b6\u6001\u65f6\uff0c\u8868\u793a\u8be5slab\u4e2d\u7ef4\u62a4\u7684\u5bf9\u8c61\u5df2\u7ecf\u5168\u90e8\u88ab\u5206\u914d\u3002\u5f53slab\u5904\u4e8e\u7a7a\u72b6\u6001\u65f6\uff0c\u548c\u534a\u6ee1\u72b6\u6001\u65f6\uff0cslab\u53ef\u4ee5\u6709\u7a7a\u95f2\u7684\u5bf9\u8c61\u53ef\u4f9b\u5206\u914d\u3002\u5f53\u5185\u6838\u9700\u8981\u7533\u8bf7\u4e00\u4e2a\u65b0\u5bf9\u8c61\u65f6\uff0c\u5c31\u5411\u5bf9\u5e94\u7684\u7f13\u5b58\u7533\u8bf7\u3002\u7f13\u5b58\u627e\u5230\u81ea\u5df1\u7ef4\u62a4\u7684slab\uff0c\u4eceslab\u4e2d\u62ff\u51fa\u9884\u5148\u5206\u914d\u597d\u7684\u7a7a\u95f2\u5bf9\u8c61\u8fd4\u56de\u7ed9\u7533\u8bf7\u8005\u3002\u5f53\u5185\u6838\u4f7f\u7528\u5b8c\u4e86\u8be5\u5bf9\u8c61\uff0c\u8fd9\u4e2a\u5bf9\u8c61\u5c31\u88ab\u7f13\u5b58\u56de\u6536\uff0c\u4e00\u822c\u60c5\u51b5\u4e0b\u5e76\u4e0d\u771f\u6b63\u91ca\u653e\uff0c\u800c\u662f\u5728\u5bf9\u5e94\u7684slab\u4e0a\u505a\u7a7a\u95f2\u6807\u8bb0\u3002\u7f13\u5b58\u901a\u8fc7\u7075\u6d3b\u7684\u7b56\u7565\u7ef4\u62a4slab\u7684\u5927\u5c0f\u548c\u6570\u91cf\u3002\u4f7f\u7528slab\uff0c\u80fd\u591f\u52a0\u901f\u5e38\u7528\u6570\u636e\u7ed3\u6784\u7684\u5206\u914d\u548c\u91ca\u653e\uff0c\u5e76\u51cf\u5c11\u5206\u914d\u5185\u5b58\u4ea7\u751f\u7684\u788e\u7247\u3002<\/p>\n

2.2 \u5185\u6838\u5f00\u53d1<\/h2>\n

      \u64cd\u4f5c\u7cfb\u7edf\u5185\u6838\u7684\u5f00\u53d1\u548c\u666e\u901a\u7528\u6237\u7a7a\u95f4\u7684\u7a0b\u5e8f\u5f00\u53d1\u6709\u975e\u5e38\u5927\u7684\u5dee\u5f02\u3002\u672c\u8282\u5c06\u4ecb\u7ecd\u7406\u89e3KSM\u548c\u5728\u5185\u6838\u7a7a\u95f4\u8fdb\u884c\u5f00\u53d1\u6240\u9700\u719f\u77e5\u7684\u4e00\u4e9b\u5185\u5bb9\u3002<\/p>\n

2.2.1 Linux\u5185\u6838\u7b80\u4ecb<\/h3>\n

Linux\u75311991\u8bde\u751f\u5f00\u59cb\u5c31\u53d7\u5230\u5f00\u6e90\u793e\u533a\u7684\u70ed\u70c8\u6b22\u8fce\uff0c\u5e76\u4e14\u4e00\u76f4\u5904\u4e8e\u6781\u4e3a\u6d3b\u8dc3\u7684\u6301\u7eed\u5f00\u53d1\u72b6\u6001\u3002Linux\u7684\u4ee3\u7801\u4ee5GNU\u8ba1\u5212\u5021\u5bfc\u7684GPL\u534f\u8bae\u81ea\u7531\u5206\u53d1\uff0c\u5168\u4e16\u754c\u7684\u64cd\u4f5c\u7cfb\u7edf\u7231\u597d\u8005\uff0c\u786c\u4ef6\u9a71\u52a8\u7f16\u5199\u8005\u90fd\u975e\u5e38\u6d3b\u8dc3\u5730\u4e3aLinux\u8d21\u732e\u4ee3\u7801\u3002Linux\u7684\u5f00\u53d1\u5982\u6b64\u6210\u529f\uff0c\u4ee5\u81f3GNU\u8ba1\u5212\u4e2d\u81ea\u5df1\u7684\u64cd\u4f5c\u7cfb\u7edf\u5185\u6838GNU Hurd\u90fd\u672a\u5f97\u5230\u8db3\u591f\u591a\u7684\u5173\u6ce8\uff0cLinux\u6210\u4e3a\u4e8b\u5b9e\u4e0aGNU\u8ba1\u5212\u7684\u64cd\u4f5c\u7cfb\u7edf\u5185\u6838\u3002<\/p>\n

Linux\u5185\u6838\u6cbf\u7528Unix\u7684\u5355\u5185\u6838\u8bbe\u8ba1\u3002\u5355\u5185\u6838\u8bbe\u8ba1\u628a\u6574\u4e2a\u5185\u6838\u8bbe\u8ba1\u6210\u8fd0\u884c\u5728\u540c\u4e00\u4e2a\u5730\u5740\u7a7a\u95f4\u7684\u4e00\u4e2a“\u5927”\u8fdb\u7a0b\u3002\u6240\u6709\u7684\u5185\u6838\u6267\u884c\u5e8f\u5217\u5b58\u5728\u4e8e\u540c\u4e00\u4e2a\u5730\u5740\u7a7a\u95f4\u4e2d\uff0c\u5e76\u5728\u540c\u4e00\u4e2a\u5730\u5740\u7a7a\u95f4\u5185\u8fd0\u884c\u3002\u56e0\u6b64\uff0c\u5185\u6838\u7684\u4e0d\u540c\u6267\u884c\u5e8f\u5217\u4e4b\u95f4\u7684\u901a\u4fe1\u662f\u6781\u4e3a\u5feb\u901f\u7684\uff0c\u57fa\u672c\u4e0d\u9700\u8981\u989d\u5916\u7684\u5f00\u9500\uff0c\u4f46\u7531\u6b64\u4e5f\u5e26\u6765\u5185\u6838\u4ee3\u7801\u7684\u590d\u6742\u5ea6\u8fc7\u9ad8\u7684\u95ee\u9898\u3002\u8f83\u4e4b\u5355\u5185\u6838\uff0c\u53e6\u4e00\u4e2a\u8bbe\u8ba1\u64cd\u4f5c\u7cfb\u7edf\u7684\u601d\u8def\u662f\u5fae\u5185\u6838\uff0c\u5b83\u7684\u5f88\u591a\u8bbe\u8ba1\u7406\u5ff5\u548c\u5355\u5185\u6838\u7684\u8bbe\u8ba1\u76f8\u53cd\uff0c\u5982windows XP, Vista \u8fd8\u6709 windows 7\u7b49\u7b49\u3002Linux\u5185\u6838\u5728\u53d1\u5c55\u8fc7\u7a0b\u4e2d\u5f15\u5165\u4e86\u5185\u6838\u6a21\u5757\u7684\u6982\u5ff5\uff0c\u8fd9\u4f7f\u5f97Linux\u5185\u6838\u65e2\u4fdd\u6301\u4e86\u5355\u5185\u6838\u8bbe\u8ba1\u6027\u80fd\u5feb\u901f\u7684\u7279\u70b9\uff0c\u53c8\u4f7f\u5f97\u5185\u6838\u4ee3\u7801\u76f8\u5bf9\u7eaf\u7cb9\u7684\u5355\u5185\u6838\u7b80\u6d01\u548c\u6613\u4e8e\u7ef4\u62a4\u3002<\/p>\n

\u672c\u8bba\u6587\u9009\u5b9a\u7684\u5185\u6838\u7248\u672c\u662f2013\u5e742\u6708\u53d1\u5e03\u76843.0.66\u7a33\u5b9a\u7248\uff0c\u5728\u5b83\u7684\u57fa\u7840\u4e0a\u7814\u7a76\u5f00\u53d1\u3002<\/p>\n

2.2.2 \u5185\u6838\u7ebf\u7a0b<\/h3>\n

Linux\u7684\u5185\u6838\u7ebf\u7a0b\u5b9e\u9645\u4e0a\u662f\u53ea\u5b58\u5728\u4e8e\u5185\u6838\u7a7a\u95f4\u7684\u4e00\u4e2a\u8fdb\u7a0b\u3002\u5185\u6838\u901a\u5e38\u521b\u5efa\u5185\u6838\u7ebf\u7a0b\u8ba9\u5b83\u5728\u540e\u53f0\u5468\u671f\u6027\u7684\u5904\u7406\u4e00\u4e9b\u4e8b\u52a1\u3002\u5185\u6838\u7ebf\u7a0b\u548c\u666e\u901a\u8fdb\u7a0b\u4e00\u6837\u53ef\u8c03\u5ea6\uff0c\u53ef\u88ab\u62a2\u5148\u3002\u4ed6\u4eec\u7684\u6700\u663e\u8457\u7684\u533a\u522b\u662f\u5185\u6838\u7ebf\u7a0b\u7684\u8fdb\u7a0b\u63cf\u8ff0\u7ed3\u6784\u4f53task_struct\u7684mm\u5b57\u6bb5\u4e3aNULL\u3002\u800c\u4e00\u822c\u8fdb\u7a0b\u7684\u8fdb\u7a0b\u63cf\u8ff0\u7ed3\u6784\u4f53\u7684mm\u5b57\u6bb5\u6307\u5411\u8be5\u8fdb\u7a0b\u7684\u5730\u5740\u7a7a\u95f4\u3002\u56e0\u4e3a\u5185\u6838\u7ebf\u7a0b\u6c38\u8fdc\u53ea\u8fd0\u884c\u5728\u5185\u6838\u6001\uff0c\u6c38\u8fdc\u4e0d\u5fc5\u5207\u6362\u81f3\u7528\u6237\u7a7a\u95f4\uff0c\u5e76\u4e14\u6240\u6709\u7528\u6237\u6001\u8fdb\u7a0b\u7684\u5730\u5740\u7a7a\u95f4\u7684\u5185\u6838\u865a\u62df\u5730\u5740\u90e8\u5206\u90fd\u662f\u4e00\u6837\u7684\uff0c\u6240\u4ee5\u5f53\u5904\u7406\u5668\u8c03\u5ea6\u5230\u5185\u6838\u8fdb\u7a0b\u65f6\uff0c\u5185\u6838\u8fdb\u7a0b\u53ef\u4ee5\u968f\u4fbf\u4f7f\u7528\u67d0\u4e2a\u7528\u6237\u6001\u8fdb\u7a0b\u7684\u5730\u5740\u7a7a\u95f4\u7684\u5185\u6838\u865a\u62df\u5730\u5740\u90e8\u5206\u3002Linux\u5185\u6838\u7ebf\u7a0b\u7684\u4f5c\u6cd5\u662f\u501f\u7528\u4e0a\u4e00\u4e2a\u666e\u901a\u7528\u6237\u6001\u8fdb\u7a0b\u7684\u7528\u6237\u7a7a\u95f4[23]<\/sup>\u3002<\/p>\n

\u5185\u6838\u7ebf\u7a0b\u7531\u5185\u6838API\u51fd\u6570kthread_create()\u521b\u5efa\uff0c\u4e5f\u53ef\u7531kthread_run()\u521b\u5efa\u3002\u4ed6\u4eec\u7684\u533a\u522b\u662f\u524d\u8005\u521b\u5efa\u7684\u662f\u4e00\u4e2a\u5904\u4e8e\u975e\u8fd0\u884c\u72b6\u6001\u7684\u5185\u6838\u7ebf\u7a0b\uff0c\u9700\u8981\u4f7f\u7528wake_up_process()\u628a\u5b83\u8f6c\u6362\u4e3a\u53ef\u8fd0\u884c\u72b6\u6001\uff1b\u800ckthread_run()\u521b\u5efa\u7684\u5185\u6838\u7ebf\u7a0b\u7acb\u5373\u5904\u4e8e\u53ef\u8fd0\u884c\u72b6\u6001\uff0c\u968f\u65f6\u53ef\u80fd\u88ab\u8c03\u5ea6\u800c\u83b7\u5f97\u8fd0\u884c\u7684\u673a\u4f1a\u3002\u5185\u6838\u7ebf\u7a0b\u5f00\u59cb\u540e\u4f1a\u4e00\u76f4\u8fd0\u884c\uff0c\u76f4\u5230\u5b83\u663e\u5f0f\u5730\u8c03\u7528do_exit()\u6216\u8005\u5176\u5b83\u5185\u6838\u4ee3\u7801\u8c03\u7528kthread_stop()\u3002kthread_stop()\u51fd\u6570\u9700\u8981\u4f20\u5165\u5148\u524d\u521b\u5efa\u5185\u6838\u7ebf\u7a0b\u51fd\u6570\u8fd4\u56de\u7684task_struct\u4f5c\u4e3a\u53c2\u6570\u3002\u8be5\u51fd\u6570\u5728\u8c03\u7528\u540e\u4f1a\u4e00\u76f4\u963b\u585e\uff0c\u76f4\u5230\u7b49\u5f85\u7684\u5185\u6838\u7ebf\u7a0b\u5b8c\u5168\u9000\u51fa\u4e86\u624d\u8fd4\u56de\u3002<\/p>\n

2.2.3 \u5185\u6838\u7684\u540c\u6b65\u673a\u5236<\/h3>\n

\u7ade\u4e89\u6761\u4ef6\u6307\u7684\u662f\u7a0b\u5e8f\u8bbe\u8ba1\u4e2d\u7684\u4e00\u79cd\u7f3a\u9677\uff0c\u8fd9\u79cd\u7f3a\u9677\u4f7f\u5f97\u7a0b\u5e8f\u7684\u8f93\u51fa\u4f1a\u56e0\u4e3a\u4e0d\u53d7\u63a7\u5236\u7684\u4e8b\u4ef6\u51fa\u73b0\u7684\u987a\u5e8f\u6216\u53d1\u751f\u65f6\u95f4\u800c\u53d1\u751f\u6539\u53d8\u3002Linux\u5185\u6838\u63d0\u4f9b\u4e86\u4e00\u5957\u540c\u6b65\u65b9\u6cd5\uff0c\u6b63\u786e\u5730\u4f7f\u7528\u540c\u6b65\u65b9\u6cd5\u53ef\u4ee5\u6d88\u9664\u7ade\u4e89\u6761\u4ef6[24]<\/sup>\u3002<\/p>\n

atomic_t\u662f\u5185\u6838\u4e2d\u7684\u7279\u6b8a\u6574\u578b\u6570\uff0c\u5e94\u7528\u5728\u8be5\u6574\u578b\u6570\u4e0a\u7684\u65b9\u6cd5\u4f7f\u5f97\u5bf9\u8be5\u6574\u6570\u7684\u64cd\u4f5c\u662f\u539f\u5b50\u64cd\u4f5c\uff0c\u4ece\u800c\u5bf9\u8be5\u6574\u6570\u7684\u64cd\u4f5c\u4e0d\u4f1a\u88ab\u5176\u5b83\u6267\u884c\u5e8f\u5217\u4e2d\u65ad\u3002\u5982atomic_inc()\u548catomic_dec()\u5206\u522b\u662f\u539f\u5b50\u5730\u7ed9\u4e00\u4e2a\u6574\u578b\u6570\u52a0\u4e00\u6216\u51cf\u4e00\u3002<\/p>\n

Linux\u5185\u6838\u4e2d\u6700\u5e38\u7528\u7684\u9501\u662f\u81ea\u65cb\u9501\u3002\u5bf9\u4e8e\u4e00\u4e2a\u81ea\u65cb\u9501\uff0c\u5185\u6838\u5728\u4efb\u4f55\u65f6\u5019\u53ea\u80fd\u6709\u4e00\u4e2a\u6267\u884c\u5e8f\u5217\u6301\u6709\u8be5\u9501\u3002\u5982\u679c\u5728\u8be5\u81ea\u65cb\u9501\u88ab\u5176\u5b83\u6267\u884c\u5e8f\u5217\u6301\u6709\u65f6\uff0c\u5f53\u524d\u6267\u884c\u5e8f\u5217\u4e5f\u7533\u8bf7\u6301\u6709\u8be5\u9501\uff0c\u5219\u8fd9\u4e2a\u6267\u884c\u5e8f\u5217\u5c31\u4f1a\u4f7f\u5f97\u5904\u7406\u5668\u4e00\u76f4\u5fd9\u7b49\u8be5\u9501\u88ab\u6301\u6709\u8005\u91ca\u653e\u3002\u4e3a\u9075\u5faa\u8fc5\u901f\u5360\u6709\uff0c\u8fc5\u901f\u91ca\u653e\u7684\u539f\u5219\uff0c\u4e00\u4e2a\u5185\u6838\u6267\u884c\u5e8f\u5217\u4e00\u4f46\u6301\u6709\u67d0\u81ea\u65cb\u9501\uff0c\u5219\u5185\u6838\u5728\u8be5\u5185\u6838\u5e8f\u5217\u8fd0\u884c\u7684\u5f53\u524d\u5904\u7406\u5668\u4e0a\u88ab\u7981\u6b62\u62a2\u5148\u3002\u53e6\u5916\uff0c\u6301\u6709\u81ea\u65cb\u9501\u7684\u5185\u6838\u6267\u884c\u5e8f\u5217\u5e94\u8be5\u8fd0\u884c\u5b8c\u7b80\u77ed\u7684\u4ee3\u7801\u540e\u8fc5\u901f\u91ca\u653e\u8be5\u81ea\u65cb\u9501\uff0c\u800c\u4e0d\u5e94\u8be5\u5728\u91ca\u653e\u6301\u6709\u7684\u81ea\u65cb\u9501\u524d\u6267\u884c\u53ef\u80fd\u9020\u6210\u7761\u7720\u7684\u4ee3\u7801\uff0c\u4e5f\u4e0d\u80fd\u663e\u5f0f\u5730\u8c03\u7528\u653e\u5f03\u5904\u7406\u5668\u800c\u7533\u8bf7\u8c03\u5ea6\u5176\u5b83\u8fdb\u7a0b\u7684\u4ee3\u7801\uff0c\u56e0\u4e3a\u8fd9\u6837\u4f1a\u4f7f\u5f97\u5176\u5b83\u7533\u8bf7\u8be5\u81ea\u65cb\u9501\u7684\u6267\u884c\u5e8f\u5217\u7b49\u5f85\u975e\u5e38\u957f\u7684\u65f6\u95f4\u800c\u5927\u5927\u635f\u5bb3\u4e86\u6574\u4e2a\u7cfb\u7edf\u7684\u6027\u80fd\u3002\u81ea\u65cb\u9501\u7684\u57fa\u672c\u6709\u6cd5\u662f\uff1a\u7528DEFINE_SPINLOCK\u5728\u7f16\u8bd1\u671f\u5b9a\u4e49\u4e00\u4e2a\u672a\u88ab\u5360\u7528\u7684\u81ea\u65cb\u9501\u53d8\u91cf\uff0c\u7528\u51fd\u6570spin_lock()\u5f97\u5230\u81ea\u65cb\u9501\uff0c\u7528spin_unlock()\u51fd\u6570\u91ca\u653e\u81ea\u65cb\u9501\u3002\u4e0e\u666e\u901a\u81ea\u65cb\u9501\u7c7b\u4f3c\u7684\u8fd8\u6709\u8bfb\u5199\u81ea\u65cb\u9501\u3002\u5f53\u5bf9\u81ea\u65cb\u9501\u4fdd\u62a4\u7684\u8d44\u6e90\u7684\u8bbf\u95ee\u591a\u6570\u662f\u8bfb\u8bbf\u95ee\uff0c\u5c11\u90e8\u5206\u662f\u5199\u8bbf\u95ee\u65f6\uff0c\u4f7f\u7528\u8bfb\u5199\u81ea\u65cb\u9501\u6bd4\u4f7f\u7528\u666e\u901a\u81ea\u65cb\u9501\u7684\u6548\u7387\u66f4\u9ad8\u3002<\/p>\n

Linux\u5185\u6838\u4e2d\u53e6\u4e00\u79cd\u5e38\u89c1\u7684\u9501\u662f\u4fe1\u53f7\u91cf\u3002\u4fe1\u53f7\u91cf\u53ea\u80fd\u5728\u8fdb\u7a0b\u4e0a\u4e0b\u6587\u4e2d\u624d\u80fd\u4f7f\u7528\uff0c\u5f53\u4e00\u4e2a\u8fdb\u7a0b\u6216\u5185\u6838\u7ebf\u7a0b\u5c1d\u8bd5\u83b7\u53d6\u4e00\u4e2a\u4e0d\u53ef\u7528\u7684\u4fe1\u53f7\u91cf\u65f6\uff0c\u8be5\u8fdb\u7a0b\u6216\u8005\u8be5\u5185\u6838\u7ebf\u7a0b\u4f1a\u88ab\u7f6e\u4e8e\u4e00\u4e2a\u7b49\u5f85\u961f\u5217\u4e2d\uff0c\u7136\u540e\u8fdb\u5165\u7761\u7720\u72b6\u6001\uff0c\u5904\u7406\u5668\u8f6c\u800c\u6267\u884c\u5176\u5b83\u7684\u4ee3\u7801\u3002\u5f53\u8be5\u4fe1\u53f7\u91cf\u88ab\u67d0\u6301\u6709\u8005\u91ca\u653e\uff0c\u4fe1\u53f7\u91cf\u53d8\u4e3a\u53ef\u7528\u65f6\uff0c\u7b49\u5f85\u961f\u961f\u4e2d\u7684\u4e00\u4e2a\u8fdb\u7a0b\u6216\u5185\u6838\u7ebf\u7a0b\u4f1a\u88ab\u5524\u9192\u800c\u83b7\u5f97\u8be5\u4fe1\u53f7\u91cf\u3002\u56e0\u4e3a\u672a\u80fd\u7acb\u5373\u83b7\u5f97\u9501\u65f6\u4f1a\u4f7f\u5f97\u6267\u884c\u5e8f\u5217\u8fdb\u5165\u7761\u7720\uff0c\u6240\u4ee5\u5728\u4e0d\u80fd\u88ab\u8c03\u5ea6\u7684\u4e2d\u65ad\u4e0a\u4e0b\u6587\u4e2d\u4e0d\u80fd\u4f7f\u7528\u4fe1\u53f7\u91cf\u3002\u540c\u6837\u56e0\u4e3a\u672a\u80fd\u7acb\u5373\u83b7\u5f97\u4fe1\u53f7\u91cf\u5219\u88ab\u7f6e\u4e8e\u7761\u7720\u72b6\u6001\u7684\u539f\u56e0\uff0c\u4fe1\u53f7\u91cf\u975e\u5e38\u9002\u5408\u9700\u8981\u957f\u65f6\u95f4\u6301\u6709\u9501\u7684\u60c5\u51b5\u3002\u4fe1\u53f7\u91cf\u7684\u53e6\u4e00\u4e2a\u663e\u8457\u7684\u7279\u70b9\u662f\u5b83\u5145\u8bb8\u540c\u65f6\u6709\u82e5\u5e72\u4e2a\u6301\u6709\u8005\uff0c\u8fd9\u4e2a\u6570\u91cf\u5728\u58f0\u660e\u4fe1\u53f7\u91cf\u65f6\u6307\u70b9\u3002\u4f46\u5927\u591a\u6570\u60c5\u51b5\u4e0b\u4fe1\u53f7\u91cf\u88ab\u8bbe\u7f6e\u4e3a\u53ea\u80fd\u6709\u4e00\u4e2a\u6301\u6709\u8005\uff0c\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u4fe1\u53f7\u91cf\u88ab\u79f0\u4e3a\u4e8c\u503c\u4fe1\u53f7\u91cf\u6216\u8005\u4e92\u65a5\u9501\u3002\u4e92\u65a5\u9501\u5e38\u89c1\u7684\u4f7f\u7528\u65b9\u6cd5\u662f\uff1a\u7528DECLARE_MUTEX\u5b8f\u5728\u7f16\u8bd1\u671f\u5b9a\u4e49\u4e00\u4e2a\u672a\u88ab\u5360\u7528\u7684\u4e92\u65a5\u9501\u53d8\u91cf\uff0c\u6216\u8005\u7528init_MUTEX\u5728\u8fd0\u884c\u65f6\u521d\u59cb\u5316\u4e92\u65a5\u9501\uff0c\u7528down()\u51fd\u6570\u83b7\u5f97\u4fe1\u53f7\u91cf\uff0c\u7528up()\u51fd\u6570\u91ca\u653e\u4fe1\u53f7\u91cf\u3002\u4e0e\u8bfb\u5199\u81ea\u65cb\u9501\u7c7b\u4f3c\uff0cLinux\u5185\u6838\u4e5f\u6709\u9488\u5bf9\u8bfb\u591a\u5199\u5c11\u7684\u60c5\u51b5\u505a\u4f18\u5316\u7684\u8bfb\u5199\u4fe1\u53f7\u91cf\uff0c\u5b83\u7684\u7279\u5f81\u548c\u666e\u901a\u4fe1\u53f7\u91cf\u57fa\u672c\u76f8\u540c\u3002<\/p>\n

2.2.4 \u5185\u6838\u7684\u8c03\u8bd5\u6280\u672f<\/h3>\n

\u8c03\u8bd5\u5185\u6838\u4ee3\u7801\u662f\u5185\u6838\u5f00\u53d1\u6280\u672f\u4e2d\u975e\u5e38\u56f0\u96be\u7684\u4e00\u90e8\u5206\uff0c\u8fd9\u662f\u56e0\u4e3a\u5185\u6838\u4ee3\u7801\u8fd0\u884c\u5728\u8f6f\u4ef6\u6808\u7684\u6700\u5e95\u5c42\uff0c\u4e0d\u50cf\u7528\u6237\u7a7a\u95f4\u7684\u8fdb\u7a0b\u53ef\u4ee5\u8f7b\u6613\u5730\u88ab\u8c03\u8bd5\u5668\u8ddf\u8e2a\u3002\u53e6\u5916\uff0c\u56e0\u4e3a\u5f88\u591a\u60c5\u51b5\u4e0b\u7684\u5185\u6838\u9519\u8bef\u4f1a\u8ba9\u6574\u4e2a\u64cd\u4f5c\u7cfb\u7edf\u5d29\u6e83\u6216\u8005\u8fd0\u884c\u5728\u4e0d\u53ef\u9884\u6d4b\u7684\u4e0d\u7a33\u5b9a\u72b6\u6001\uff0c\u8ba9\u5f00\u53d1\u8005\u51e0\u4e4e\u6ca1\u6709\u673a\u4f1a\u6536\u96c6\u5230\u8db3\u591f\u591a\u7684\u9519\u8bef\u662f\u5982\u4f55\u51fa\u73b0\u7684\u7ebf\u7d22\uff0c\u6240\u4ee5\u5185\u6838\u9519\u8bef\u5728\u5f88\u591a\u60c5\u51b5\u4e0b\u4e5f\u4e0d\u80fd\u8f7b\u6613\u5730\u88ab\u91cd\u73b0\u3002<\/p>\n

       \u7528printk()\u51fd\u6570\u6253\u5370\u51fa\u7a0b\u5e8f\u7684\u76f8\u5173\u4fe1\u606f\u5230\u65e5\u5fd7\u6587\u4ef6\u6216\u63a7\u5236\u53f0\u662f\u6700\u53e4\u8001\u4e5f\u6700\u5e38\u7528\u4e14\u6709\u6548\u7684\u8c03\u8bd5\u65b9\u6cd5[25]<\/sup>\u3002printk()\u51fd\u6570\u4e0e\u7528\u6237\u7a7a\u95f4\u7684printf()\u5e93\u51fd\u6570\u76f8\u4f3c\uff0c\u5176\u4e2d\u7684\u5dee\u522b\u4e4b\u4e00\u662fprintk()\u51fd\u6570\u53ef\u4ee5\u8ba9\u7528\u6237\u6307\u5b9a\u6253\u5370\u4fe1\u606f\u7684\u7ea7\u522b\u3002\u76ee\u524dprintk()\u51fd\u6570\u6709\u516b\u4e2a\u4fe1\u606f\u7ea7\u522b\uff0c\u5b83\u4eec\u88ab\u5b9a\u4e49\u5728linux\/kernel.h\u5934\u6587\u4ef6\u4e2d\u3002\u7ea7\u522b\u7684\u6570\u5b57\u8d8a\u5c0f\u5219\u8868\u793a\u7ea7\u522b\u8d8a\u9ad8\u3002\u57fa\u4e8e\u4fe1\u606f\u7ea7\u522b\uff0c\u5185\u6838\u53ef\u80fd\u628a\u4fe1\u606f\u6253\u5370\u5230\u5f53\u524d\u7684\u63a7\u5236\u53f0\u3002\u5b83\u53ef\u80fd\u662f\u4e00\u4e2a\u5b57\u7b26\u7ec8\u7aef\uff0c\u53ef\u80fd\u662f\u4e00\u4e2a\u4e32\u53e3\u8fde\u63a5\u7684\u8bbe\u5907\uff0c\u4e5f\u53ef\u80fd\u662f\u4e00\u4e2a\u5e76\u53e3\u6253\u5370\u673a\u3002\u5185\u6838\u4e2d\u7684\u6574\u578b\u53d8\u91cfconsole_loglevel\u8868\u793a\u80fd\u88ab\u53d1\u5f80\u63a7\u5236\u53f0\u7684\u4fe1\u606f\u7684\u6700\u5c0f\u7ea7\u522b\u3002\u53ef\u4ee5\u7528sys_syslog\u7cfb\u7edf\u8c03\u7528\u6539\u53d8\u5b83\u7684\u503c\uff0c\u7528\u53ef\u4ee5\u901a\u8fc7\u5199\u6587\u4ef6\/proc\/sys\/kernel\/printk\u6539\u53d8\u5b83\u3002\u6240\u6709\u4fe1\u606f\uff0c\u5305\u62ec\u4fe1\u606f\u7ea7\u522b\u7684\u503c\u5927\u4e8econsole_loglevel\u800c\u6ca1\u80fd\u88ab\u53d1\u5f80\u63a7\u5236\u53f0\u7684\u4fe1\u606f\u90fd\u88ab\u6dfb\u52a0\u5230\u6587\u4ef6\/var\/log\/messages\u7684\u672b\u5c3e\u3002<\/p>\n

\u9664\u4e86\u6700\u4e3a\u5e38\u7528\u7684\u6253\u5370\u51fd\u6570printk()\u662f\u8c03\u8bd5\u5185\u6838\u5fc5\u5907\u4e4b\u5916\u3002\u5185\u6838\u5f00\u53d1\u8005\u4f7f\u7528\u7684\u5185\u6838\u5728\u7f16\u8bd1\u524d\u901a\u5e38\u90fd\u4f1a\u6253\u5f00\u4e00\u4e9b\u65b9\u4fbf\u8c03\u8bd5\u7684\u5185\u6838\u9009\u9879[26]<\/sup>\u3002\u6bd4\u5982CONFIG_KALLSYMS\u9009\u9879\u4f7f\u5f97\u5185\u6838\u4ee3\u7801\u7684\u7b26\u53f7\u4fe1\u606f\u88ab\u7f16\u8bd1\u8fdb\u5185\u6838\uff0c\u8fd9\u6837\u5f53\u5185\u6838\u5d29\u6e83\u65f6\uff0c\u7cfb\u7edf\u4f1a\u7528\u7b26\u53f7\u6253\u5370\u51fa\u51fa\u9519\u65f6\u6808\u56de\u6eaf\u4fe1\u606f\uff0c\u5426\u5219\u53ea\u6709\u4e8c\u8fdb\u5236\u7684\u5730\u5740\u4fe1\u606f\u3002\u8fd8\u6709\u4e00\u4e9b\u7279\u5b9a\u7684\u7f16\u8bd1\u9009\u9879\u5e2e\u52a9\u5f00\u53d1\u8005\u6392\u67e5\u7279\u5b9a\u7684\u9519\u8bef\uff0c\u6bd4\u5982CONFIG_DEBUG_SLAB\u53ef\u4ee5\u5e2e\u52a9\u6392\u67e5\u5fd8\u8bb0\u521d\u59cb\u5316\u5185\u5b58\u548c\u5185\u5b58\u8d8a\u754c\u8bbf\u95ee\u7684\u9519\u8bef\uff1b\u800cCONFIG_DEBUG_SPINLOCK \u53ef\u4ee5\u6392\u67e5\u975e\u6cd5\u4f7f\u7528\u81ea\u65cb\u9501\u7684\u9519\u8bef\u3002<\/p>\n

KGDB\u662f\u5e38\u7528\u7684\u8c03\u8bd5Linux\u5185\u6838\u7684\u8c03\u8bd5\u5668\u3002\u6700\u5f00\u59cb\uff0c\u5b83\u53ea\u662f\u4f5c\u4e3a\u4e00\u4e2a\u5185\u6838\u8865\u4e01\u53d1\u5e03\uff0c\u4ece\u5185\u68382.6.26\u5f00\u59cb\uff0c\u5b83\u88ab\u5408\u5e76\u5230\u4e86\u5185\u6838\u7684\u4e3b\u5e72\u4ee3\u7801\u3002\u7528KGDB\u8c03\u8bd5\u65f6\uff0c\u9700\u8981\u4e24\u53f0\u7528\u4e32\u53e3\u8fde\u63a5\u7684Linux\u673a\u5668\uff0c\u88ab\u8c03\u8bd5\u7684\u673a\u5668\u8fd0\u884cKGDB\uff0c\u53e6\u4e00\u53f0(\u8c03\u8bd5\u673a)\u5219\u8fd0\u884c\u666e\u901a\u7684GDB\u3002GDB\u8fdc\u7a0b\u534f\u8bae\u88ab\u7528\u4e8e\u5b83\u4eec\u4e4b\u95f4\u7684\u901a\u8baf[27]<\/sup>\u3002\u914d\u7f6eKGDB\u6bd4\u8f83\u9ebb\u70e6\uff0c\u4f46\u76ee\u524d\u684c\u9762\u865a\u62df\u5316\u6280\u672f\u975e\u5e38\u6210\u719f\uff0c\u5f00\u53d1\u8005\u53ef\u4ee5\u7528\u4e24\u53f0Linux\u865a\u62df\u673a\u4f7f\u7528KGDB\uff0c\u7528\u865a\u62df\u7684\u4e32\u53e3\u786c\u4ef6\u8fde\u63a5\u4e24\u53f0\u673a\u5668\u3002\u4ec5\u7ba1\u5982\u6b64\uff0c\u4f7f\u7528\u5185\u6838\u8c03\u8bd5\u5668\u8fd8\u662f\u76f8\u5f53\u4e4b\u9ebb\u70e6\u3002\u88ab\u8c03\u8bd5\u7684\u5185\u6838\u5728\u7f16\u8bd1\u540e\u8f93\u51fa\u7684vmlinux\u6587\u4ef6\u662f\u672a\u538b\u7f29\u7684linux\u5185\u6838\uff0c\u9700\u8981\u88ab\u62f7\u8d1d\u5230\u8c03\u8bd5\u673a\uff1b\u5bf9\u5e94\u7684\u6e90\u4ee3\u7801\u9700\u8981\u88ab\u62f7\u8d1d\u5230\u8c03\u8bd5\u673a\u8c03\u8bd5\u65f6\u7684\u5f53\u524d\u76ee\u5f55\uff1b\u53e6\u5916\uff0c\u8c03\u8bd5\u65f6\u5e76\u4e0d\u80fd\u5728\u6240\u6709\u4ee3\u7801\u8bed\u53e5\u8bbe\u7f6e\u65ad\u70b9\uff0c\u56e0\u4e3a\u5185\u6838\u4ee3\u7801\u7684\u7f16\u8bd1\u4f9d\u8d56\u4e8eGCC\u7684\u7f16\u8bd1\u4f18\u5316\u9009\u9879\uff0c\u5f00\u542f\u76f8\u5e94\u7684\u4f18\u5316\u9009\u9879\u5185\u6838\u4ee3\u7801\u624d\u80fd\u901a\u8fc7\u7f16\u8bd1\uff0c\u800c\u5f88\u591a\u8bed\u53e5\u7684\u53d8\u91cf\u7ecf\u8fc7GCC\u4f18\u5316\u540e\u4f1a\u88ab\u53bb\u6389\uff0c\u8c03\u8bd5\u8005\u4ece\u6e90\u4ee3\u7801\u4e0a\u770b\u5230\u7684\u6267\u884c\u8def\u5f84\u7ecf\u5e38\u5e76\u975e\u5185\u6838\u5b9e\u9645\u7684\u6267\u884c\u8def\u5f84\u3002<\/p>\n

2.3 \u672c\u7ae0\u5c0f\u7ed3<\/h2>\n

    \u672c\u7ae0\u9996\u5148\u4ecb\u7ecd\u4e86Linux\u5185\u6838\u7684\u5185\u5b58\u7ba1\u7406\u7684\u4e00\u4e9b\u7406\u8bba\u548c\u6280\u672f\uff0c\u7136\u540e\u4ecb\u7ecd\u4e86\u8fdb\u884c\u5185\u6838\u5f00\u53d1\u6240\u5fc5\u987b\u638c\u63e1\u7684\u57fa\u7840\u77e5\u8bc6\u3002\u672c\u7ae0\u7684\u5185\u5bb9\u662f\u7406\u89e3\u4ee5\u540e\u7ae0\u8282\u7684\u57fa\u7840\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"

Linux\u684c\u9762\u73af\u5883\u4e0b\u5185\u5b58\u53bb\u91cd\u6280\u672f\u7684\u7814\u7a76\u4e0e\u5b9e\u73b0 \u5728\u8fd9\u91cc\u53ef\u4ee5\u4e0b\u8f7d\u539f\u7a3f www.ykyi.net\/upload\/Research_and_Implementation_of_Memory_Deduplication_in_the_Linux_Desktop_Environment.pdf \u7b2c\u4e8c\u7ae0 \u76f8\u5173\u7406\u8bba\u4e0e\u6280\u672f 2.1 \u5185\u5b58\u7ba1\u7406 \u5185\u5b58\u7ba1\u7406\u662f\u64cd\u4f5c\u7cfb\u7edf\u5185\u6838\u4e2d\u6781\u4e3a\u91cd\u8981\u7684\u90e8\u5206\uff0c\u5b83\u6d89\u53ca\u7269\u7406\u5730\u5740\u3001\u865a\u62df\u5730\u5740\u3001\u5206\u6bb5\u3001\u5206\u9875\u7b49\u8bf8\u591a\u6982\u5ff5\u3002 2.1.1 \u5185\u5b58\u5730\u5740 \u7a0b\u5e8f\u4f7f\u7528\u5730\u5740\u6765\u8bbf\u95ee\u5185\u5b58\u5355\u5143\u3002\u5bf9\u4e8ex86\u67b6\u6784\u7684\u4e2d\u592e\u5904\u7406\u5668\uff0c\u4f7f\u7528\u903b\u8f91\u5730\u5740\uff0c\u865a\u62df\u5730\u5740\uff0c\u7269\u7406\u5730\u5740\u4e09\u79cd\u4e0d\u540c\u7684\u5730\u5740[15]\u3002 \u903b\u8f91\u5730\u5740\u5305\u62ec\u6bb5\u548c\u504f\u79fb\u5730\u5740\u4e24\u90e8\u5206\uff0c\u5b83\u4eec\u5171\u540c\u7528\u6765\u6307\u5b9a\u673a\u5668\u6307\u4ee4\u6216\u8005\u64cd\u4f5c\u6570\u5728\u5185\u5b58\u4e2d\u7684\u4f4d\u7f6e\u3002\u903b\u8f91\u5730\u5740\u5bf9\u5e94\u4e0b\u6587\u63d0\u5230\u7684\u5206\u6bb5\u5f0f\u5185\u5b58\u7ba1\u7406\u3002 \u865a\u62df\u5730\u5740\u4e5f\u88ab\u79f0\u4f5c\u7ebf\u6027\u5730\u5740\uff0c\u5b83\u8868\u793a\u4e00\u4e2a\u5bfb\u5740\u7a7a\u95f4\u3002\u5728Linux\u64cd\u4f5c\u7cfb\u7edf\u4e2d\uff0c\u4f7f\u7528\u4e00\u4e2a\u65e0\u7b26\u53f7\u957f\u6574\u578b\u5b58\u50a8\u865a\u62df\u5730\u5740\u3002\u5982\u679c\u662f\u9488\u5bf932\u4f4dx86\u5904\u7406\u5668\u7684\u5185\u6838\uff0c\u8fd9\u662f\u4e00\u4e2a32\u4f4d\u7684\u65e0\u7b26\u53f7\u957f\u6574\u578b\uff0c\u53ef\u4ee5\u5bfb\u5740\u81f3\u591a232\uff0c\u53734GB\u7a7a\u95f4\u3002\u800cLinux\u5728x86_64\u5904\u7406\u5668\u4e0a\uff0c\u4e00\u4e2a\u65e0\u7b26\u53f7\u957f\u6574\u578b\u670964\u4f4d\uff0c\u4f46\u5b9e\u9645\u4e0a\u53ea\u4f7f\u7528\u4e8648\u4f4d\uff0c\u5373\u53ef\u5bfb\u5740\u5230248 \uff0c\u5373256TB\u7684\u5185\u5b58\u7a7a\u95f4\u3002\u5f15\u5165\u865a\u62df\u5730\u5740\u4f7f\u5f97\u7528\u6237\u7a7a\u95f4\u7684\u8fdb\u7a0b\u90fd\u72ec\u81ea\u62e5\u6709\u4e00\u4e2a\u5730\u5740\u7a7a\u95f4\uff0c\u65b9\u4fbf\u64cd\u4f5c\u7cfb\u7edf\u5728\u786c\u4ef6\u7684\u534f\u52a9\u4e0b\u9694\u79bb\u8fdb\u7a0b\u8bbf\u95ee\u5185\u5b58\u7684\u64cd\u4f5c\uff0c\u4ece\u800c\u5b9e\u73b0\u66f4\u9ad8\u7684\u5b89\u5168\u6027\u548c\u4fbf\u6377\u6027\u3002\u572832\u4f4d\u5904\u7406\u5668\u67b6\u6784\u4e0b\uff0c4G\u865a\u62df\u5730\u5740\u7a7a\u95f4\u5212\u5206\u6210\u4e24\u90e8\u5206\uff0c\u9ad8\u7aef\u76841G\u7a7a\u95f4\u88ab\u79f0\u4e4b\u4e3a\u5185\u6838\u7a7a\u95f4\uff0c\u4f4e\u7aef\u76843G\u7a7a\u95f4\u79f0\u4e4b\u4e3a\u7528\u6237\u7a7a\u95f4\u3002\u5185\u6838\u7684\u4ee3\u7801\u548c\u6570\u636e\u5b58\u5728\u5185\u6838\u7a7a\u95f4\uff0c\u7528\u6237\u7a7a\u95f4\u7684\u8fdb\u7a0b\u901a\u8fc7\u7cfb\u7edf\u8c03\u7528\u9677\u5165\u5185\u6838\u7a7a\u95f4\u6267\u884c\u5185\u6838\u7a7a\u95f4\u7684\u4ee3\u7801\u3002\u5bf9\u4e8e64\u4f4d\u5904\u7406\u5668\uff0c\u865a\u62df\u5730\u5740\u540c\u6837\u5206\u4e3a\u5185\u6838\u7a7a\u95f4\u548c\u7528\u6237\u7a7a\u95f4\uff0c\u53ea\u662f\u9488\u5bf964\u4f4d\u5904\u7406\u5668\u7684\u5185\u6838\u62e5\u6709\u5927\u5f97\u591a\u7684\u5bfb\u5740\u8303\u56f4\uff0c\u5bf9\u5185\u6838\u7a7a\u95f4\u548c\u7528\u6237\u7a7a\u95f4\u7684\u5730\u5740\u5212\u5206\u6709\u591a\u79cd\u5b9e\u73b0\u3002 \u7269\u7406\u5730\u5740\u88ab\u4e2d\u592e\u5904\u7406\u5668\u7528\u6765\u5bfb\u5740\u5185\u5b58\u82af\u7247\u4e0a\u7684\u5b9e\u9645\u7684\u7269\u7406\u5355\u5143\u3002\u5b83\u5bf9\u5e94\u4e86\u9001\u5f80\u5904\u7406\u5668\u7684\u9488\u811a\u4e0a\u7684\u9ad8\u4f4e\u7535\u5e73\u4fe1\u53f7\u3002        Linux\u4e2d\u7684\u5185\u5b58\u7ba1\u7406\u5355\u5143 (Memory Management Unit, MMU)\u5728\u786c\u4ef6\u7535\u8def\u7684\u5e2e\u52a9\u4e0b\u628a\u903b\u8f91\u5730\u5740\u8bd1\u6210\u7ebf\u6027\u5730\u5740\uff1b\u800c\u53e6\u4e00\u4e2a\u786c\u4ef6\u7535\u8def\u5219\u5e2e\u52a9\u628a\u7ebf\u6027\u5730\u5740\u7ffb\u8bd1\u6210\u7269\u7406\u5730\u5740\u3002 2.1.2 \u6bb5\u9875\u5f0f\u5185\u5b58\u7ba1\u7406 \u5185\u5b58\u5206\u6bb5\u662f\u753180×86\u5904\u7406\u5668\u5f15\u5165\u7684\u6982\u5ff5\uff0c\u5b83\u9f13\u52b1\u7a0b\u5e8f\u5458\u5728\u8bbe\u8ba1\u7a0b\u5e8f\u65f6\u628a\u7a0b\u5e8f\u4f7f\u7528\u7684\u5185\u5b58\u6309\u7167\u903b\u8f91\u4e0a\u7684\u610f\u4e49\u76f8\u5173\u6027\u5206\u6210\u82e5\u5e72\u4e2a\u90e8\u5206\uff0c\u6bd4\u5982\u6709\u4e9b\u6bb5\u5b58\u653e\u5168\u5c40\u6570\u636e\uff0c\u6709\u4e9b\u6bb5\u5b58\u653e\u7a0b\u5e8f\u4ee3\u7801[16]\u3002 \u5185\u5b58\u7ba1\u7406\u5355\u5143\u7684\u5206\u9875\u5355\u5143\u534f\u52a9\u628a\u865a\u62df\u5730\u5740\u8bd1\u4e3a\u7269\u7406\u5730\u5740\uff0c\u4e3a\u4e86\u63d0\u9ad8\u7ffb\u8bd1\u7684\u6548\u7387\uff0c\u865a\u62df\u5730\u5740\u88ab\u6309\u7167\u56fa\u5b9a\u957f\u5ea6\u5207\u5206\u6210\u4e00\u4e2a\u4e2a\u5c0f\u5355\u5143\uff0c\u5b83\u4eec\u5219\u88ab\u79f0\u4e4b\u4e3a\u9875\u9762\u3002\u9875\u9762\u53ef\u4ee5\u770b\u6210\u662fMMU\u7ba1\u7406\u5185\u5b58\u7684\u6700\u5c0f\u5355\u4f4d\u3002       \u5206\u6bb5\u548c\u5206\u9875\u90fd\u7528\u6765\u5212\u5206\u5185\u5b58\uff0c\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\uff0c\u5b83\u4eec\u7684\u529f\u80fd\u6709\u4e00\u5b9a\u91cd\u5408\u3002\u5b9e\u9645\u4e0a\uff0cLinux\u5185\u6838\u7684\u5185\u5b58\u7ba1\u7406\u673a\u5236\u503e\u5411\u4e8e\u4f7f\u7528\u5206\u9875\u6280\u672f\u3002Linux\u8fdb\u7a0b\u8fd0\u884c\u5728\u7528\u6237\u7a7a\u95f4\u65f6\u4f7f\u7528\u7684\u6807\u5fd7\u4ee3\u7801\u6bb5\u7684\u4ee3\u7801\u6bb5\u9009\u62e9\u5b50(segmentation selector)\u548c\u6570\u636e\u6bb5\u9009\u62e9\u5b50\u662f\u76f8\u7b49\u7684\uff1b\u8fdb\u7a0b\u8fd0\u884c\u5728\u5185\u6838\u7a7a\u95f4\u65f6\u4f7f\u7528\u7684\u4ee3\u7801\u6bb5\u9009\u62e9\u5b50\u548c\u6570\u636e\u6bb5\u9009\u62e9\u5b50\u4e5f\u662f\u76f8\u7b49\u7684\u3002\u800c\u4e14\u8fd9\u56db\u4e2a\u6bb5\u9009\u62e9\u5b50\u7684\u6bb5\u57fa\u5740\u90fd\u8bbe\u7f6e\u4e3a0\u3002\u8fd9\u610f\u5473\u7740\u5728Linux\u64cd\u4f5c\u7cfb\u7edf\u4e2d\uff0c\u65e0\u8bba\u5bfb\u5740\u6570\u636e\u548c\u8fd8\u662f\u5bfb\u5740\u6307\u4ee4\uff0c\u65e0\u8bba\u5728\u7528\u6237\u7a7a\u95f4\u8fd8\u662f\u5185\u6838\u7a7a\u95f4\uff0c\u903b\u8f91\u5730\u5740\u7684\u6bb5\u57fa\u5740\u90e8\u5206\u4e3a0\uff0c\u504f\u79fb\u5730\u5740\u90e8\u5206\u521a\u597d\u7b49\u4e8e\u865a\u62df\u5730\u5740\u3002 \u5728Linux\u6240\u652f\u6301\u7684\u5927\u591a\u6570\u786c\u4ef6\u5e73\u53f0\u4e0a\uff0c\u9ed8\u8ba4\u7684\u9875\u9762\u5927\u5c0f\u662f4K\u3002\u4f46Linux\u540c\u65f6\u4e5f\u652f\u6301\u5927\u4e8e4K\u7684\u9875\u9762\u7684\u5185\u5b58\u7ba1\u7406\u3002\u8fd0\u884c\u5728\u7528\u6237\u7a7a\u95f4\u7684\u4ee3\u7801\u53ef\u4ee5\u4f7f\u7528glibc\u5e93\u4e2d\u7684getpagesize()\u51fd\u6570\u5f97\u5230\u5f53\u524d\u4f7f\u7528\u7684\u9875\u9762\u5927\u5c0f\u3002\u672c\u8bba\u6587\u53ea\u9488\u5bf9\u5728x86_64\u67b6\u6784\u4e0a\u9875\u9762\u5927\u5c0f\u662f4K\u7684Linux\u5185\u6838\u3002\u5b9e\u9645\u4e0a\u4ece\u5185\u68382.6.38\u5f00\u59cb\uff0c\u5185\u6838\u4e2d\u5f00\u59cb\u652f\u6301\u900f\u660e\u5de8\u9875(Transparent Huge Page)[17]\uff0c\u5185\u6838\u4e2d\u6709\u4e9b\u9875\u9762\u7684\u5927\u5c0f\u5b9e\u9645\u4e0a\u662f2M\uff0c\u4f46\u8fd9\u4e0d\u5f71\u54cd\u6309\u71674K\u7684\u9875\u9762\u5927\u5c0f\u5c55\u5f00\u8ba8\u8bba\u3002 Linux\u4f7f\u7528\u5206\u7ea7\u9875\u8868\u7684\u65b9\u5f0f\u628a\u865a\u62df\u5730\u5740\u6620\u5c04\u5230\u9875\u9762\u3002\u572832\u4f4d\u5904\u7406\u5668\u4e0a\u4f7f\u7528\u4e8c\u7ea7\u9875\u8868\uff0c\u5728x86_64\u67b6\u6784\u7684\u5904\u7406\u5668\u4e0a\u5219\u4f7f\u7528\u56db\u7ea7\u9875\u8868\u3002     \u56fe2-1 \u56db\u7ea7\u9875\u8868          \u5982\u56fe2-1\u6240\u793a\uff0c\u4ee5\u9488\u5bf9x86_64\u67b6\u6784\u5904\u7406\u5668\u7684Linux\u5185\u6838\u4e3a\u4f8b\uff0c64\u4f4d\u865a\u62df\u5730\u5740\u7684\u9ad816\u4f4d\u4e0d\u88ab\u4f7f\u7528\uff0c\u4f4e48\u4f4d\u88ab\u5e73\u5747\u5206\u4e3a5\u6bb5\uff0coffset\u6bb5\u536012\u4f4d\uff0c\u5176\u5b83\u56db\u4e2a\u6bb5\u5404\u53609\u4f4d\u3002\u8fd9\u4e2a\u5212\u5206\u5728\u6e90\u4ee3\u7801\u6587\u4ef6arch\/x86\/include\/asm\/pgtable_64_types.h\u4e2d\u5b9a\u4e49\u3002cr3\u5bc4\u5b58\u5668\u5b58\u50a8\u4e86\u9875\u5168\u5c40\u76ee\u5f55\u7684\u7269\u7406\u5730\u5740\u3002\u5728\u628a\u865a\u62df\u5730\u5740\u7ffb\u8bd1\u5230\u7269\u7406\u5730\u5740\u7684\u8fc7\u7a0b\u4e2d\uff0cMMU\u5148\u4ececr3\u5bc4\u5b58\u5668\u4e2d\u53d6\u51fa\u5168\u5c40\u76ee\u5f55\u7684\u7269\u7406\u5730\u5740\uff0c\u518d\u52a0\u4e0aGLOBALDIR\u6bb5\u7b97\u51fa\u7684\u504f\u79fb\u91cf\uff0c\u4ece\u800c\u5728\u9875\u5168\u5c40\u76ee\u5f55\u4e2d\u5f97\u5230\u9875\u4e0a\u7ea7\u76ee\u5f55\u7684\u7269\u7406\u5730\u5740\u3002\u4e0e\u6b64\u7c7b\u4f3c\uff0c\u4ece\u9875\u4e0a\u7ea7\u76ee\u5f55\u4e2d\u5f97\u5230\u9875\u4e2d\u95f4\u76ee\u5f55\u7684\u5730\u5740\uff0c\u7136\u540e\u5f97\u5230\u9875\u8868\u7684\u5730\u5740\uff0c\u518d\u5f97\u5230\u9875\u9762\u7684\u5730\u5740\uff0c\u6700\u540e\u7684OFFSET\u5b57\u6bb5\u5219\u5b9a\u4f4d\u5230\u9875\u9762\u4e2d\u7684\u4e00\u4e2a\u5b57\u8282\u3002\u81f3\u6b64\uff0c\u865a\u62df\u5730\u5740\u88ab\u7ffb\u8bd1\u5230\u4e86\u7269\u7406\u5730\u5740\u3002 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Linux\u5185\u6838\u7528\u4e00\u4e2astruct page\u7ed3\u6784\u4f53\u63cf\u8ff0\u4e00\u4e2a\u9875\u9762\u7684\u4fe1\u606f\u3002\u8fd9\u4e2a\u7ed3\u6784\u4f53\u5b9a\u4e49\u5728include\/linux\/mm_types.h\u6587\u4ef6\u4e2d[19]\u3002\u56fe2-2\u5217\u51fa\u8fd9\u4e2a\u7ed3\u6784\u4f53\u4e2d\u4e0e\u672c\u8bba\u6587\u76f4\u63a5\u76f8\u5173\u7684\u5b57\u6bb5\u3002   \u56fe2-2 struct page\u7684\u90e8\u5206\u5b57\u6bb5   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2.1.3 \u5185\u6838\u4e2d\u7684\u5de8\u9875 \u73b0\u4ee3\u5904\u7406\u5668\u7684\u5185\u5b58\u7ba1\u7406\u5355\u5143\u51e0\u4e4e\u90fd\u80fd\u5904\u7406\u96644KB\u5927\u5c0f\u5916\u7684\u591a\u79cd\u9875\u9762\u5c3a\u5bf8\u3002\u7136\u800c\uff0cLinux\u5185\u6838\u5728\u51e0\u4e4e\u6240\u4ee5\u5e73\u53f0\u4e0a\u7684\u5b9e\u73b0\u90fd\u9009\u7528\u6700\u5c0f\u7684\u9875\u9762\u5927\u5c0f\uff0c\u53734KB\uff0c\u6bd44KB\u66f4\u5927\u7684\u9875\u9762\uff0c\u90fd\u88ab\u79f0\u4e4b\u4e3a\u5de8\u9875(huge 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Lookaside Buffer\uff0cTLB)\u7684\u547d\u4e2d\u6548\u7387[20]\u3002 \u5728\u5185\u68382.6.38\u7248\u672c\u4e4b\u524d\uff0c\u552f\u4e00\u4f7f\u7528\u5de8\u9875\u7684\u65b9\u5f0f\u662f\u901a\u8fc7\u975e\u5e38\u590d\u6742\u7684hugetlbfs\u6587\u4ef6\u7cfb\u7edf\u3002\u5e94\u7528\u7a0b\u5e8f\u5f00\u53d1\u8005\u548c\u7cfb\u7edf\u7ba1\u7406\u5458\u90fd\u9700\u8981\u6ce8\u610f\u4e00\u4e9b\u7279\u522b\u4e8b\u9879\u624d\u80fd\u591f\u5f00\u542f\u5de8\u9875\u529f\u80fd\u3002\u56e0\u6b64\u53ea\u6709\u6781\u5c11\u6570\u771f\u6b63\u9700\u8981\u5de8\u9875\u5e26\u6765\u6027\u80fd\u63d0\u9ad8\u7684\u7528\u6237\uff0c\u5982\u4e13\u7528\u6570\u636e\u5e93\u7cfb\u7edf\uff0c\u624d\u4f7f\u7528\u5de8\u9875\u3002 … Continue reading 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