{"id":5481,"date":"2021-08-17T15:23:31","date_gmt":"2021-08-17T07:23:31","guid":{"rendered":"https:\/\/damogame.cn\/wordpress\/?p=5481"},"modified":"2021-08-17T15:23:31","modified_gmt":"2021-08-17T07:23:31","slug":"%e9%ab%98%e6%80%a7%e8%83%bd%e5%bc%82%e6%ad%a5io%e6%9c%ba%e5%88%b6%ef%bc%9aio_uring","status":"publish","type":"post","link":"https:\/\/i007.cc\/wordpress\/archives\/5481","title":{"rendered":"\u9ad8\u6027\u80fd\u5f02\u6b65IO\u673a\u5236\uff1aIO_URING"},"content":{"rendered":"

\u539f\u6587\u5730\u5740<\/a><\/p>\n

 <\/p>\n

\u4ed9\u4eba\u638c\u5f00\u53c9 2021-06-16 13:58:29 67 \u6536\u85cf 2
\n\u5206\u7c7b\u4e13\u680f\uff1a \u6587\u4ef6\u7cfb\u7edf \u534f\u8bae\u6808
\n\u7248\u6743<\/p>\n

\u6587\u4ef6\u7cfb\u7edf
\n\u540c\u65f6\u88ab 2 \u4e2a\u4e13\u680f\u6536\u5f55
\n3 \u7bc7\u6587\u7ae00 \u8ba2\u9605
\n\u8ba2\u9605\u4e13\u680f<\/p>\n

\u534f\u8bae\u6808
\n15 \u7bc7\u6587\u7ae00 \u8ba2\u9605
\n\u8ba2\u9605\u4e13\u680f
\n\u9ad8\u6027\u80fd\u5f02\u6b65IO\u673a\u5236\uff1aIO_URING
\n\u4e00\u3001\u524d\u8a00
\n1.1 \u5f02\u6b65IO\u673a\u5236
\nLinux\u5185\u6838\u63d0\u4f9b\u7684IO\u673a\u5236\u5927\u90fd\u662f\u540c\u6b65\u5b9e\u73b0\u7684\uff0c\u5982\u5e38\u89c4\u7684read\/write\/send\/recv\u7b49\u7cfb\u7edf\u8c03\u7528\u3002\u540c\u6b65IO\u673a\u5236\u5b58\u5728\u7740\u4e00\u5b9a\u7684\u5f0a\u7aef\uff0c\u4f8b\u5982\uff1a\uff081\uff09IO\u7684\u5b9e\u73b0\u90fd\u662f\u5728\u5f53\u524d\u8fdb\u7a0b\u4e0a\u4e0b\u6587\u7684\u7cfb\u7edf\u8c03\u7528\u4e2d\u5b8c\u6210\u7684\uff0c\u4f1a\u963b\u585e\u5f53\u524d\u8fdb\u7a0b\uff0c\u964d\u4f4e\u7cfb\u7edf\u7684\u5b9e\u65f6\u6027\uff1b\uff082\uff09\u6027\u80fd\u8f83\u4f4e\u3002<\/p>\n

\u5f02\u6b65IO\u6307\u7684\u662f\u7528\u6237\u7a0b\u5e8f\u5c06IO\u8bf7\u6c42\u63d0\u4ea4\u540e\uff0c\u65e0\u9700\u7b49\u5f85IO\u64cd\u4f5c\u7684\u5b8c\u6210\uff0c\u800c\u662f\u53ef\u4ee5\u7ee7\u7eed\u5904\u7406\u522b\u7684\u4e8b\u60c5\u3002\u5f53IO\u64cd\u4f5c\u5b8c\u6210\u540e\uff0c\u4f1a\u4ee5\u67d0\u79cd\u65b9\u5f0f\u901a\u77e5\u7528\u6237\u7a0b\u5e8f\u3002Linux\u7cfb\u7edf\u4e0b\u73b0\u6709\u7684\u5f02\u6b65IO\u673a\u5236\u7684\u5b9e\u73b0\u4e3b\u8981\u4e3a\u4e24\u79cd\uff1a<\/p>\n

POSIX AIO\u3002\u8fd9\u79cd\u65b9\u6848\u662f\u7528\u6237\u6001\u5b9e\u73b0\u7684\u5f02\u6b65IO\u673a\u5236\uff0c\u5176\u6838\u5fc3\u601d\u60f3\u4e3a\uff1a\u521b\u5efa\u4e00\u4e2a\u4e13\u95e8\u7528\u6765\u5904\u7406IO\u7684\u7ebf\u7a0b\uff0c\u7528\u6237\u7a0b\u5e8f\u5c06IO\u64cd\u4f5c\u4ea4\u7ed9\u8be5\u7ebf\u7a0b\u6765\u8fdb\u884c\u3002\u8fd9\u79cd\u65b9\u5f0f\u5b9e\u73b0\u7684\u5f02\u6b65IO\u6548\u7387\u548c\u6269\u5c55\u6027\u90fd\u6bd4\u8f83\u5dee\u3002
\nLINUX AIO\u3002Linux\u5185\u6838\u91cc\u4e5f\u5b9e\u73b0\u4e86\u4e00\u5957\u5f02\u6b65IO\u673a\u5236\uff0c\u88ab\u79f0\u4e3aAIO\u3002\u8be5\u673a\u5236\u7684\u4f7f\u7528\u9650\u5236\u6bd4\u8f83\u5927\uff0c\u6bd4\u5982\u53ea\u652f\u6301direct IO\u800c\u65e0\u6cd5\u4f7f\u7528cache\uff0c\u4e14\u6269\u5c55\u6027\u6bd4\u8f83\u5dee\u3002
\n\u5728\u6b64\u80cc\u666f\u4e0b\uff0cLinux\u793e\u533a\u57285.1\u7248\u672c\u4e2d\u5f15\u5165\u4e86\u4e00\u79cd\u5168\u65b0\u7684\u5f02\u6b65IO\u673a\u5236\uff1aio_uring\u3002io_uring\u63d0\u4f9b\u4e86\u4e00\u5957\u5168\u65b0\u7684\u7cfb\u7edf\u8c03\u7528\u63a5\u53e3\uff0c\u51ed\u501f\u7740\u5176\u9ad8\u6027\u80fd\u3001\u9ad8\u6269\u5c55\u6027\u7b49\u4f18\u52bf\u8131\u9896\u800c\u51fa\uff0c\u6210\u4e3a\u4e86\u76ee\u524dLinux\u4e0b\u4e3b\u6d41\u7684\u5f02\u6b65IO\u65b9\u6848\u3002<\/p>\n

1.2 \u4f18\u52bf
\n\u76f8\u6bd4\u4e8e\u73b0\u6709\u7684\u5f02\u6b65IO\u673a\u5236\uff0cio_uring\u7684\u4f18\u52bf\u4e3b\u8981\u4f53\u73b0\u5728\u4ee5\u4e0b\u51e0\u65b9\u9762\uff1a<\/p>\n

\u9ad8\u6548\u3002\u4e00\u65b9\u9762\uff0cio_uring\u91c7\u7528\u4e86\u5171\u4eab\u5185\u5b58\u7684\u65b9\u5f0f\u6765\u4f20\u9012\u53c2\u6570\uff0c\u51cf\u5c11\u4e86\u6570\u636e\u62f7\u8d1d\uff1b\u53e6\u4e00\u65b9\u9762\uff0c\u5176\u91c7\u7528ringBuf\u7684\u65b9\u5f0f\u6765\u5b9e\u73b0\u6279\u91cf\u7684IO\u8bf7\u6c42\uff0c\u51cf\u5c11\u4e86\u7cfb\u7edf\u8c03\u7528\u7684\u6b21\u6570\u3002
\n\u53ef\u6269\u5c55\u6027\u5f3a\u3002io_uring\u5177\u6709\u8d85\u5f3a\u7684\u53ef\u6269\u5c55\u6027\uff0c\u5177\u4f53\u8868\u73b0\u5728\uff1a\uff081\uff09\u5176\u652f\u6301\u7684IO\u8bbe\u5907\u7c7b\u578b\u591a\u6837\u5316\uff0c\u4e0d\u4ec5\u652f\u6301\u5757\u8bbe\u5907\u7684IO\uff0c\u8fd8\u652f\u6301\u4efb\u4f55\u57fa\u4e8e\u6587\u4ef6\u7684IO\uff0c\u4f8b\u5982\u5957\u63a5\u53e3\u3001\u5b57\u7b26\u8bbe\u5907\u7b49\uff1b\uff082\uff09\u5176\u652f\u6301\u7684IO\u64cd\u4f5c\u591a\u6837\u5316\uff0c\u4e0d\u4ec5\u652f\u6301\u5e38\u89c4\u7684read\/write\uff0c\u8fd8\u652f\u6301send\/recv\/sendmsg\/recvmsg\/close\/sync\u7b49\u5927\u91cf\u7684\u64cd\u4f5c\uff0c\u800c\u4e14\u80fd\u591f\u5f88\u7075\u6d3b\u5730\u8fdb\u884c\u6269\u5145\u3002
\n\u6613\u7528\u3002io_uring\u63d0\u4f9b\u4e86\u914d\u5957\u7684liburing\u5e93\uff0c\u5176\u5bf9io_uring\u7684\u7cfb\u7edf\u8c03\u7528\u8fdb\u884c\u4e86\u5927\u91cf\u7684\u5c01\u88c5\uff0c\u4f7f\u5f97\u63a5\u53e3\u53d8\u5f97\u7b80\u5355\u6613\u7528\u3002
\n\u53ef\u4f38\u7f29\u3002io_uring\u63d0\u4f9b\u4e86poll\u6a21\u5f0f\uff0c\u5bf9\u4e8eIO\u6027\u80fd\u8981\u6c42\u8f83\u9ad8\u7684\u573a\u666f\uff0c\u5141\u8bb8\u7528\u6237\u727a\u7272\u4e00\u5b9a\u7684CPU\u6765\u83b7\u5f97\u66f4\u9ad8\u7684IO\u6027\u80fd\uff1a\u4f4e\u5ef6\u8fdf\u3001\u9ad8IOPS\u3002
\n\u7ecf\u6d4b\u8bd5\uff0c\u76f8\u6bd4\u4e8elibaio\uff0c\u5728poll\u6a21\u5f0f\u4e0bio_uring\u6027\u80fd\u63d0\u5347\u5c06\u8fd1150%\uff0c\u582a\u6bd4SPDK\u3002\u7279\u522b\u662f\u5728\u9ad8QD\u7684\u60c5\u51b5\u4e0b\uff0c\u66f4\u662f\u6709\u8d76\u8d85SPDK\u7684\u8d8b\u52bf\u3002<\/p>\n

\u4e8c\u3001io_uring\u6574\u4f53\u6846\u67b6
\nio_uring\u7684\u6574\u4f53\u6846\u67b6\u5982\u4e0b\u56fe\u6240\u793a\uff0c\u7528\u6237\u6001\u7a0b\u5e8f\u5728\u5f00\u53d1\u65f6\u53ea\u9700\u8981\u8c03\u7528liburing\u63d0\u4f9b\u7684\u63a5\u53e3\u6765\u8fdb\u884c\u5f02\u6b65IO\u8bf7\u6c42\u7684\u63d0\u4ea4\uff0cliburing\u4f1a\u6839\u636e\u7528\u6237\u7684\u8bf7\u6c42\u5728\u5171\u4eab\u5185\u5b58\u4e2d\u8bbe\u7f6e\u5bf9\u5e94\u7684\u53c2\u6570\u3002\u5f02\u6b65IO\u8bf7\u6c42\u53ef\u4ee5\u540c\u65f6\u8bbe\u7f6e\u591a\u4e2a\uff0c\u8fd9\u4e2a\u8fc7\u7a0b\u4e2d\u4e0d\u53d1\u751f\u7cfb\u7edf\u8c03\u7528\uff0c\u5f53\u7528\u6237\u8bbe\u7f6e\u597d\u540e\u518d\u8c03\u7528liburing\u7684\u63a5\u53e3\u901a\u77e5\u5185\u6838\u5904\u7406\u5171\u4eab\u5185\u5b58\u4e2d\u7684IO\u8bf7\u6c42\uff0c\u4ece\u800c\u5b9e\u73b0\u64cd\u4f5c\u7684\u6279\u91cf\u8fdb\u884c\u3002<\/p>\n

 <\/p>\n

\u5185\u6838\u7684io_uring\u6a21\u5757\u5728\u5904\u7406\u5171\u4eab\u5185\u5b58\u4e2d\u7684\u8bf7\u6c42\u65f6\uff0c\u4f1a\u6839\u636e\u8bf7\u6c42\u7684\u7c7b\u578b\u4ee5\u53ca\u64cd\u4f5c\u7684\u6587\u4ef6\u6240\u5c5e\u7684\u6587\u4ef6\u7cfb\u7edf\u7c7b\u578b\u6765\u8c03\u7528\u4e0d\u540c\u7684IO\u63a5\u53e3\u3002\u5177\u4f53\u5f02\u6b65\u7a0b\u5e8f\u7684\u7f16\u5199\u4ee5\u53caio_uring\u7684\u5b9e\u73b0\u539f\u7406\u5c06\u5728\u4e0b\u6587\u8be6\u7ec6\u4ecb\u7ecd\u3002<\/p>\n

\u4e09\u3001io_uring\u539f\u7406
\n3.1 ringBuf
\n\u4ece\u540d\u5b57uring\u6211\u4eec\u5c31\u53ef\u4ee5\u770b\u51fa\u6765\uff0c\u8be5\u673a\u5236\u7684\u6838\u5fc3\u5373user\u548cring\uff1a\u5176\u7533\u8bf7\u4e86\u4e00\u5757\u7528\u6237\u6001\u548c\u5185\u6838\u6001\u5171\u4eab\u7684\u5185\u5b58\uff0c\u5e76\u5728\u5171\u4eab\u5185\u5b58\u4e2d\u901a\u8fc7ringBuf\u73af\u5f62\u7f13\u5b58\u961f\u5217\u7684\u65b9\u5f0f\u6765\u5b9e\u73b0\u5185\u6838\u6001\u548c\u7528\u6237\u6001\u7684\u901a\u4fe1\uff0c\u8fd9\u91cc\u7b80\u5355\u8bf4\u4e00\u4e0b\u8be5\u673a\u5236\u7684\u4f7f\u7528\u548c\u5b9e\u73b0\u8fc7\u7a0b\u3002<\/p>\n

\u6bcf\u4e00\u4e2aio_uring\u5b9e\u4f8b\uff0c\u90fd\u4f1a\u88ab\u5206\u914d\u4e00\u4e2afd\uff0c\u8be5\u8fc7\u7a0b\u662f\u901a\u8fc7io_uring_setup()\u7cfb\u7edf\u8c03\u7528\u5b9e\u73b0\u7684\u3002\u8be5\u7cfb\u7edf\u8c03\u7528\u4f1a\u6839\u636e\u7528\u6237\u63d0\u4f9b\u7684\u53c2\u6570\uff0c\u5206\u914d\u4e00\u5757\u5171\u4eab\u5185\u5b58\uff0c\u8be5\u5185\u5b58\u53ef\u4ee5\u901a\u8fc7mmap()\u7684\u65b9\u5f0f\u6620\u5c04\u5230\u7528\u6237\u6001\u3002\u8fd9\u5757\u5171\u4eab\u5185\u5b58\u4e2d\uff0c\u5305\u542b\u4e86\u4e00\u4e2aSQ\uff08\u63d0\u4ea4\u961f\u5217\uff09\u3001\u4e00\u4e2aCQ\uff08\u5b8c\u6210\u961f\u5217\uff09\u548c\u4e00\u4e2aSQE\uff08\u63d0\u4ea4\u5b9e\u4f53\uff09\u6570\u7ec4\u3002\u5176\u4e2d\uff0cSQ\u548cCQ\u662f\u4e24\u4e2a\u73af\u5f62\u961f\u5217\uff0c\u961f\u5217\u4e2d\u7684\u5143\u7d20\u662fSQE\u5728SQE\u6570\u7ec4\u4e2d\u7684\u504f\u79fb\u91cf\uff0c\u4f7f\u7528\u8fd9\u79cd\u65b9\u5f0f\u53ef\u4ee5\u4f7f\u5f97\u63d0\u4ea4\u5b9e\u4f53\u80fd\u591f\u88ab\u968f\u673a\u8bbf\u95ee\uff0c\u63d0\u9ad8\u7075\u6d3b\u6027\u3002\u7528\u6237\u4eceCQ\u7684\u5934\u90e8\u83b7\u53d6SEQ\uff0c\u5c06\u60f3\u8981\u6267\u884c\u7684\u64cd\u4f5c\uff08\u5982\u6587\u4ef6\u7684\u8bfb\u5199\uff09\u521d\u59cb\u5316\u5230\u5176\u4e2d\uff0c\u5e76\u6dfb\u52a0\u5230SQ\u961f\u5217\u7684\u5c3e\u90e8\uff0c\u7136\u540e\u4f7f\u7528io_uring_enter()\u7cfb\u7edf\u8c03\u7528\u6765\u8fdb\u884c\u63d0\u4ea4\u961f\u5217\u7684\u5904\u7406\u3002<\/p>\n

 <\/p>\n

\u5185\u6838\u4f1a\u4eceSQ\u4e2d\u4f9d\u6b21\u53d6\u51fa\u5bf9\u5e94\u7684\u63d0\u4ea4\u5b9e\u4f53\uff0c\u5e76\u6839\u636e\u63d0\u4ea4\u5b9e\u4f53\u4e2d\u5b9a\u4e49\u7684\u52a8\u4f5c\u6765\u6267\u884c\u5bf9\u5e94\u7684\u64cd\u4f5c\u3002\u7531\u4e8e\u7528\u6237\u53ea\u64cd\u4f5cSQ\u5c3e\u90e8\uff0c\u800c\u5185\u6838\u53ea\u64cd\u4f5c\u5934\u90e8\uff0c\u56e0\u6b64\u4e24\u8005\u5bf9\u4e8e\u5171\u4eab\u961f\u5217\u7684\u8bbf\u95ee\u5e76\u4e0d\u4f1a\u4ea7\u751f\u51b2\u7a81\uff0c\u8282\u7701\u4e86\u9501\u7684\u5f00\u9500\u3002\u4e0a\u56fe\u4e2d\u4e3a\u5185\u6838\u7684\u5904\u7406\u6d41\u7a0b\u7b80\u56fe\uff0c\u4e3a\u4e86\u63d0\u9ad8\u6027\u80fd\u3001\u964d\u4f4e\u65f6\u5ef6\uff0c\u5185\u6838\u5e76\u4e0d\u662f\u4e00\u5b9a\u4f1a\u91c7\u7528\u5f02\u6b65\u7684\u65b9\u5f0f\u6765\u5904\u7406\u63d0\u4ea4\u5b9e\u4f53\uff0c\u800c\u662f\u4f1a\u68c0\u67e5\u8be5\u5b9e\u4f53\u6240\u5bf9\u5e94\u7684\u6587\u4ef6\u7cfb\u7edf\u662f\u5426\u652f\u6301\u975e\u963b\u585e\u5f0f\u7684\u64cd\u4f5c\u3002\u5bf9\u4e8e\u5757\u8bbe\u5907\u7684\u8bfb\u5199\uff0c\u53ef\u80fd\u5e76\u4e0d\u4f1a\u652f\u6301\u975e\u963b\u585e\u5f0f\u64cd\u4f5c\uff0c\u4f46\u662f\u5bf9\u4e8e\u5176\u4ed6\u7684\u4e00\u4e9b\u6587\u4ef6\u7cfb\u7edf\uff0c\u5982\u7f51\u7edc\u5957\u63a5\u5b57\uff0c\u662f\u652f\u6301\u975e\u963b\u585e\u5f0f\u62a5\u6587\u63a5\u6536\u7684\u3002\u663e\u800c\u6613\u89c1\uff0c\u5f53socket\u63a5\u6536\u961f\u5217\u4e2d\u5b58\u5728\u62a5\u6587\u65f6\uff0c\u8fdb\u884c\u5f02\u6b65\u62a5\u6587\u8bfb\u53d6\u65e0\u7591\u662f\u4e0d\u660e\u667a\u7684\uff0c\u4e0d\u4ec5\u4f1a\u589e\u52a0\u5f00\u9500\uff0c\u8fd8\u4f1a\u5bfc\u81f4\u6536\u5305\u7684\u5ef6\u8fdf\u3002\u56e0\u6b64\uff0c\u5185\u6838\u4f1a\u9996\u5148\u91c7\u7528\u975e\u963b\u585e\u7684\u65b9\u5f0f\u8fdb\u884c\u62a5\u6587\u7684\u8bfb\u53d6\uff0c\u5f53\u6536\u62a5\u961f\u5217\u4e2d\u4e0d\u5b58\u5728\u62a5\u6587\u65f6\uff08\u4f1a\u8fd4\u56deEAGAIN\u9519\u8bef\uff09\uff0c\u624d\u4f1a\u5c06\u63d0\u4ea4\u5b9e\u4f53\u6dfb\u52a0\u5230\u5f02\u6b65\u961f\u5217\uff0c\u7b49\u5f85\u62a5\u6587\u7684\u5230\u6765\u3002<\/p>\n

\u5728\u64cd\u4f5c\u5b8c\u6210\u540e\uff0c\u5185\u6838\u4f1a\u5c06\u5b8c\u6210\u4e86\u7684\u63d0\u4ea4\u5b9e\u4f53\u653e\u5230CQ\u961f\u5217\u7684\u5c3e\u90e8\uff0c\u65b9\u4fbf\u7528\u6237\u7ee7\u7eed\u8fdb\u884c\u64cd\u4f5c\u7684\u63d0\u4ea4\u3002\u901a\u8fc7ringBuf\u7684\u4f7f\u7528\uff0cio_uring\u83b7\u5f97\u4e86\u4ee5\u4e0b\u51e0\u70b9\u6536\u76ca\uff1a<\/p>\n

\u80fd\u591f\u4ee5\u6279\u91cf\u7684\u65b9\u5f0f\u8fdb\u884cIO\u7684\u63d0\u4ea4\uff0c\u51cf\u5c11\u4e86\u7cfb\u7edf\u8c03\u7528\u7684\u6b21\u6570\uff0c\u8282\u7701\u4e86\u5f00\u9500\uff1b
\n\u901a\u8fc7\u5171\u4eab\u5185\u5b58\u7684\u4f7f\u7528\uff0c\u907f\u514d\u4e86\u7528\u6237\u6001\u4e0e\u5185\u6838\u6001\u9891\u7e41\u7684\u7cfb\u7edf\u8c03\u7528\u53c2\u6570\u62f7\u8d1d\uff0c\u63d0\u5347\u4e86\u6027\u80fd\u3002
\n3.2 poll\u6a21\u5f0f
\n\u4e3a\u4e86\u8fdb\u4e00\u6b65\u63d0\u9ad8\u6027\u80fd\uff0cio_uring\u8fd8\u63d0\u4f9b\u4e86\u4e24\u79cd\u8f6e\u8be2\u6a21\u5f0f\uff0c\u5373\u5757\u8bbe\u5907\u5c42\u7684iopoll\u8f6e\u8be2\u6a21\u5f0f\u548c\u63d0\u4ea4sqpoll\u8f6e\u8be2\u6a21\u5f0f\u3002<\/p>\n

3.2.1 iopoll
\n\u4ec0\u4e48\u662fIO\u8f6e\u8be2\uff08poll\uff09\u6a21\u5f0f\uff1f\u8f6e\u8be2\u6a21\u5f0f\u662f\u76f8\u5bf9\u4e8e\u4e2d\u65ad\u6a21\u5f0f\u7684\u3002\u5e38\u89c4\u7684\u5757\u8bbe\u5907IO\u4f7f\u7528\u7684\u90fd\u662f\u4e2d\u65ad\u6a21\u5f0f\uff0c\u5373\u8fdb\u7a0b\u5c06IO\u8bf7\u6c42\u63d0\u4ea4\u7ed9\u5757\u8bbe\u5907\u540e\u4f1a\u8fdb\u5165\u7761\u7720\uff08D\uff09\u72b6\u6001\uff0c\u5757\u8bbe\u5907\u5728\u5904\u7406\u5b8cIO\u8bf7\u6c42\u540e\u4f1a\u89e6\u53d1\u786c\u4e2d\u65ad\uff0c\u786c\u4e2d\u65ad\u4e2d\u4f1a\u5524\u9192\u8fdb\u7a0b\u5e76\u901a\u77e5\u5176IO\u7684\u5b8c\u6210\u3002io_uring\u63d0\u4f9b\u4e86\u4e00\u79cdblock\u5c42\u7684\u8f6e\u8be2\u6a21\u5f0f\uff0c\u5373IO\u8bf7\u6c42\u63d0\u4ea4\u540e\u4e0d\u8fdb\u5165\u7761\u7720\uff0c\u800c\u662f\u5faa\u73af\u68c0\u67e5\u786c\u4ef6\u8bbe\u5907\u7684\u5b8c\u6210\u72b6\u6001\u3002\u8be5\u6a21\u5f0f\u4e0b\uff0cio_uring\u4f1a\u989d\u5916\u542f\u52a8\u4e00\u4e2a\u5185\u6838\u8fdb\u7a0b\u6765\u5faa\u73af\u68c0\u67e5IO\u7684\u5b8c\u6210\u3002\u7531\u4e8e\u4e0d\u9700\u8981\u7b49\u5f85\u786c\u4ef6\u8bbe\u5907\u7684\u901a\u77e5\uff0c\u56e0\u6b64\u53ef\u4ee5\u66f4\u5feb\u5730\u83b7\u53d6\u5230IO\u8bf7\u6c42\u7684\u5b8c\u6210\uff0c\u8fd9\u5bf9\u4e8e\u5ef6\u8fdf\u975e\u5e38\u4f4e\u4ee5\u53caIOPS\u5f88\u9ad8\u7684\u8bbe\u5907\uff0c\u80fd\u591f\u663e\u8457\u63d0\u9ad8\u6027\u80fd\uff0c\u540c\u65f6\u907f\u514d\u4e86\u9ad8\u9891\u7684\u4e2d\u65ad\u6240\u5e26\u6765\u7684\u6027\u80fd\u5f00\u9500\u3002<\/p>\n

3.2.2 sqpoll
\n\u901a\u8fc7ringBuf\u7684\u4f7f\u7528\uff0c\u6211\u4eec\u73b0\u5728\u53ef\u4ee5\u6279\u91cf\u5730\u8fdb\u884cIO\u64cd\u4f5c\u7684\u63d0\u4ea4\uff0c\u964d\u4f4e\u4e86\u7cfb\u7edf\u8c03\u7528\u6b21\u6570\u3002io_uring\u8fd8\u63d0\u4f9b\u4e86\u53e6\u4e00\u79cd\u673a\u5236\u7528\u4e8e\u8fdb\u4e00\u6b65\u964d\u4f4e\u7cfb\u7edf\u8c03\u7528\u6b21\u6570\u3001\u63d0\u9ad8IO\u6548\u7387\uff0c\u5373\uff1a\u63d0\u4ea4\u961f\u5217\u8f6e\u8be2SQPOLL\u6a21\u5f0f\u3002<\/p>\n

 <\/p>\n

\u8be5\u6a21\u5f0f\u4e0b\uff0c\u5185\u6838\u4f1a\u542f\u52a8\u4e00\u4e2a\u5185\u6838\u8fdb\u7a0b\u4e13\u95e8\u7528\u4e8eSQE\u63d0\u4ea4\u5b9e\u4f53\u7684\u5904\u7406\uff0c\u8be5\u8fdb\u7a0b\u4f1a\u5faa\u73af\u68c0\u67e5\u63d0\u4ea4\u961f\u5217\u4e2d\u662f\u5426\u5b58\u5728\u5b9e\u4f53\u3002\u7528\u6237\u6001\u7a0b\u5e8f\u53ea\u9700\u8981\u53d6\u51fa\u5b8c\u6210\u961f\u5217\u4e2d\u7684SEQ\uff0c\u8fdb\u884c\u521d\u59cb\u5316\u5e76\u6dfb\u52a0\u5230\u63d0\u4ea4\u961f\u5217\u4e2d\u5373\u53ef\uff0c\u6574\u4e2a\u8fc7\u7a0b\u90fd\u4e0d\u9700\u8981\u4ea7\u751f\u7cfb\u7edf\u8c03\u7528\u3002\u4e3a\u4e86\u964d\u4f4e\u5f00\u9500\uff0c\u5185\u6838\u8fdb\u7a0b\u4f1a\u6709\u4e00\u4e2a\u8d85\u65f6\u65f6\u95f4\uff0c\u5728\u8be5\u65f6\u95f4\u6bb5\u5185\u5982\u679c\u90fd\u6ca1\u6709\u68c0\u6d4b\u5230\u63d0\u4ea4\u961f\u5217\u4e2d\u5b58\u5728\u5b9e\u4f53\uff0c\u5c31\u4f1a\u8fdb\u5165\u7761\u7720\u72b6\u6001\uff0c\u540c\u65f6\u5c06\u8fdb\u7a0b\u7684\u72b6\u6001\u66f4\u65b0\u5230\u5171\u4eab\u5185\u5b58\u4e2d\u3002\u7528\u6237\u8fdb\u7a0b\u5728\u63d0\u4ea4SQE\u4e4b\u540e\uff0c\u4f1a\u901a\u8fc7\u8be5\u6807\u5fd7\u4f4d\u68c0\u67e5poll\u8fdb\u7a0b\u662f\u5426\u5728\u8fd0\u884c\u3002\u82e5\u672a\u8fd0\u884c\uff0c\u5219\u901a\u8fc7io_uring_enter\u7cfb\u7edf\u8c03\u7528\u5524\u9192poll\u8fdb\u7a0b\u3002<\/p>\n

\u53ef\u4ee5\u770b\u51fa\uff0c\u5728\u9ad8IO\u9891\u7387\u7684\u60c5\u51b5\u4e0b\uff0c\u4f7f\u7528\u8be5\u6a21\u5f0f\u53ef\u4ee5\u5927\u5e45\u964d\u4f4e\u7cfb\u7edf\u8c03\u7528\u7684\u6b21\u6570\uff0c\u540c\u65f6\u51cf\u5c11\u7531\u4e8e\u7cfb\u7edf\u8c03\u7528\u800c\u5e26\u6765\u7684IO\u5ef6\u8fdf\u3002<\/p>\n

3.3 \u56fa\u5b9a\u6587\u4ef6\u548c\u56fa\u5b9a\u7f13\u51b2\u533a
\n3.3.1 \u6ce8\u518c\u6587\u4ef6
\n\u6bcf\u6b21\u5c06\u6587\u4ef6\u63cf\u8ff0\u7b26\u586b\u5145\u5230 sqe\uff0c\u7136\u540e\u63d0\u4ea4\u7ed9\u5185\u6838\u65f6\uff0c\u5185\u6838\u90fd\u5fc5\u987b\u68c0\u7d22\u5bf9\u6587\u4ef6\u63cf\u8ff0\u7b26\u7684\u5f15\u7528
\n\u5f53 IO \u5b8c\u6210\u540e\uff0c\u4f1a\u518d\u6b21\u5220\u9664\u6587\u4ef6\u5f15\u7528\uff0c\u7531\u4e8e\u6587\u4ef6\u5f15\u7528\u7684\u539f\u5b50\u6027\uff0c\u8fd9\u6837\u5bf9\u9ad8 IOPS \u7684\u5de5\u4f5c\u573a\u666f\u800c\u8a00\uff0c\u901f\u5ea6\u4f1a\u660e\u663e\u4e0b\u964d\u3002
\n\u4e3a\u4e86\u7f13\u89e3\u6b64\u95ee\u9898\uff0cio_uring \u63d0\u4f9b\u4e86\u4e00\u79cd\u5bf9 io_uring \u5b9e\u4f8b\u9884\u6ce8\u518c\u6587\u4ef6\u96c6\u7684\u65b9\u6cd5<\/p>\n

int io_uring_register(unsigned int fd, unsigned int opcode, void *arg, unsigned int nr_args);
\n1
\nfd \u662f io_uring \u5b9e\u4f8b\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26
\nopcode \u6267\u884c\u7684\u6ce8\u518c\u7c7b\u578b\u3002
\n\u5bf9\u4e8e\u6ce8\u518c\u6587\u4ef6\u96c6\u6765\u8bf4\uff0c\u5fc5\u987b\u662f IORING_REGISTER_FILES\u3002
\narg \u5fc5\u987b\u6307\u5411\u5e94\u7528\u51c6\u5907\u6253\u5f00\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u6570\u7ec4
\nnr_args \u4fbf\u662f\u6570\u7ec4\u7684\u5927\u5c0f
\n\u4e00\u65e6 io_uring_register \u6210\u529f\u5c06\u6587\u4ef6\u96c6\u6ce8\u518c\u540e\uff0c\u5e94\u7528\u5c31\u53ef\u4ee5\u5c06\u6587\u4ef6\u96c6\u6570\u7ec4\u7684\u7d22\u5f15\uff08\u800c\u4e0d\u662f\u4f7f\u7528\u5b9e\u9645\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\uff09\u8d4b\u503c\u7ed9 sqe->fd \u4e86\uff0c\u5e76\u8bbe\u7f6e sqe->flags \u5b57\u6bb5\u4e3a IOSQE_FIXED_FILE \u6765\u6807\u8bb0 sqe->fd \u662f\u4e00\u4e2a\u6587\u4ef6\u96c6\u7d22\u5f15<\/p>\n

\u5e94\u7528\u53ef\u4ee5\u7ee7\u7eed\u4f7f\u7528\u672a\u6ce8\u518c\u7684\u6587\u4ef6\uff0c\u5373\u4f7f\u662f\u6ce8\u518c\u8fc7\u7684\u6587\u4ef6\u4e5f\u53ef\u4ee5\u901a\u8fc7\u6587\u4ef6\u63cf\u8ff0\u7b26\u8d4b\u503c sqe->fd\uff0csqe->flags\u4e0d\u8bbe\u7f6e IO_FIXED_FILE \u6765\u6b63\u5e38\u4f7f\u7528\u6587\u4ef6\u63cf\u8ff0\u7b26<\/p>\n

\u5f53 io_uring \u5b9e\u4f8b\u88ab\u79fb\u9664\u540e\uff0c\u6ce8\u518c\u7684\u6587\u4ef6\u96c6\u4f1a\u81ea\u52a8\u91ca\u653e\uff0c\u6216\u8005\u4f7f\u7528 IORING_UNREGISTER_FILES opcode \u6765\u8c03\u7528 io_uring_register<\/p>\n

3.3.2 \u6ce8\u518c\u7f13\u51b2\u533a
\n\u4e0d\u4ec5\u4ec5\u53ef\u4ee5\u6ce8\u518c\u6587\u4ef6\u96c6\uff0c\u8fd8\u53ef\u4ee5\u6ce8\u518c\u4e00\u7ec4\u56fa\u5b9a IO \u7f13\u51b2\u533a\uff08fixed IO buffers)<\/p>\n

\u4f7f\u7528 O_DIRECT \u65f6\uff0c\u5185\u6838\u5728\u771f\u6b63\u6267\u884c IO \u524d\uff0c\u5fc5\u987b\u6620\u5c04\u5e94\u7528\u5185\u5b58\u9875(pages) \u5230\u5185\u6838\u4e2d\uff0c\u5e76\u4e14\u5f53 IO \u5b8c\u6210\u540e\u53d6\u6d88\u5bf9\u8fd9\u4e9b\u9875\u7684\u6620\u5c04\u3002
\n\u8fd9\u4e9b\u64cd\u4f5c\u7684\u5f00\u9500\u53ef\u80fd\u662f\u6602\u8d35\u7684\u3002\u5982\u679c\u5e94\u7528\u53ef\u4ee5\u590d\u7528 IO \u7f13\u51b2\u533a\uff0c\u90a3\u4e48\u603b\u5171\u53ea\u9700\u8981\u8fdb\u884c\u4e00\u6b21\u6620\u5c04\u548c\u53d6\u6d88\u6620\u5c04\uff0c\u800c\u4e0d\u662f\u6bcf\u6b21 IO \u64cd\u4f5c\u90fd\u9700\u8981<\/p>\n

\u8981\u6ce8\u518c\u4e00\u7ec4\u56fa\u5b9a\u7f13\u5b58\u533a\uff0cio_uring_register \u5fc5\u987b\u4f7f\u7528 IORING_REGISTER_BUFFERS \u7684 opcode \u6765\u8c03\u7528\uff0cargs \u5fc5\u987b\u5305\u542b\u586b\u5145\u597d\u6bcf\u4e2a iovec \u7684\u5730\u5740\u548c\u957f\u5ea6\u5b57\u6bb5\u7684 iovec \u6570\u7ec4\uff0cnr_args \u5219\u662f iovec \u6570\u7ec4\u7684\u5927\u5c0f<\/p>\n

\u6210\u529f\u6ce8\u518c\u56fa\u5b9a\u7f13\u51b2\u533a\u540e\uff0c\u5e94\u7528\u53ef\u4ee5\u4f7f\u7528 IORING_OP_READ_FIXED \u548c IORING_OP_WRITE_FIXED \u5728 IO \u4e2d\u5229\u7528\u8fd9\u4e9b\u7f13\u51b2\u533a\u3002
\n\u5f53\u4f7f\u7528 \u56fa\u5b9a\u64cd\u4f5c\u7801(fixed op-codes) \u65f6\uff0csqe->addr \u5fc5\u987b\u5305\u542b\u4e86\u90a3\u4e9b\u56fa\u5b9a\u7f13\u51b2\u533a\u4e4b\u4e00\u7684\u7d22\u5f15\uff0c\u5e76\u4e14 sqe->len\u4e3a\u8bf7\u6c42\u7684\u5b57\u8282\u957f\u5ea6\u3002
\n\u5e94\u7528\u53ef\u80fd\u4f1a\u6ce8\u518c\u5927\u4e8e IO \u64cd\u4f5c\u7684\u7f13\u51b2\u533a\uff0c\u4e00\u4e2a\u56fa\u5b9a\u7684\u8bfb\/\u5199\u53ea\u662f\u4e00\u4e2a\u56fa\u5b9a\u7f13\u51b2\u533a\u7684\u5b50\u96c6\u662f\u5b8c\u5168\u5408\u6cd5\u7684\u3002<\/p>\n

\u56db\u3001\u6027\u80fd\u6d4b\u8bd5\u53ca\u5206\u6790
\n4.1 \u5b58\u50a8\u8bbe\u5907\u6027\u80fd\u5206\u6790
\n4.1.1 \u5feb\u901f\u5b58\u50a8\u82af\u7247
\n\u5728\u5feb\u901f\u7684\u5b58\u50a8\u8bbe\u5907\u4e0a\uff0c\u59823D xpoint\u3001SATA\u7b49\uff0cio_uring\u53d6\u5f97\u4e86\u53ef\u89c2\u7684\u6027\u80fd\u63d0\u5347\u3002\u4ee5\u4e0b\u4e3aLinux-AIO\u3001io_uring\u4ee5\u53caspdk\u7684\u6027\u80fd\u5bf9\u6bd4\u6570\u636e\uff0c\u8be5\u6570\u636e\u7531io_uring\u7684\u4f5c\u8005Jens Axboe\u63d0\u4f9b\u3002\u5176\u4e2dspdk\u662fintel\u63d0\u51fa\u7684\u4ece\u9a71\u52a8\u5c42\u9762\u5b9e\u73b0\u7684\u9ad8\u6027\u80fd\u5b58\u50a8\u8bbe\u5907\u6846\u67b6\uff0c\u53ef\u4ee5\u8bf4\u662f\u9ad8\u6027\u80fd\u5b58\u50a8\u65b9\u6848\u4e2d\u7684\u6807\u6746\u3002\u8be5\u6570\u636e\u7684\u6d4b\u8bd5\u65b9\u5f0f\u4e3a\uff1a\u57283D xpoint\u5b58\u50a8\u8bbe\u5907\u4e0a\u8fdb\u884c4k\u5927\u5c0f\u7684\u968f\u673a\u8bfb\u53d6\u64cd\u4f5c\uff0c\u8861\u91cf\u7684\u6307\u6807\u4e3a\uff1a<\/p>\n

Latency\uff1a\u8bfb\u53d6\u6570\u636e\u7684\u5ef6\u8fdf
\nIOPS\uff1a\u6bcf\u79d2\u5185IO\u64cd\u4f5c\u7684\u6b21\u6570\uff0c\u8fd9\u91cc\u4e3a\u6bcf\u79d2\u80fd\u591f\u8bfb\u53d64k\u6570\u636e\u7684\u6b21\u6570
\nInterface QD Polled Latency IOPS
\nio_uring 1 0 9.5usec 77K
\nio_uring 2 0 8.2usec 183K
\nio_uring 4 0 8.4usec 383K
\nio_uring 8 0 13.3usec 449K
\nlibaio 1 0 9.7usec 74K
\nlibaio 2 0 8.5usec 181K
\nlibaio 4 0 8.5usec 373K
\nlibaio 8 0 15.4usec 402K
\nio_uring 1 1 6.1usec 139K
\nio_uring 2 1 6.1usec 272K
\nio_uring 4 1 6.3usec 519K
\nio_uring 8 1 11.5usec 592K
\nspdk 1 1 6.1usec 151K
\nspdk 2 1 6.2usec 293K
\nspdk 4 1 6.7usec 536K
\nspdk 8 1 12.6usec 586K
\n\u4ece\u6570\u636e\u4e2d\u53ef\u4ee5\u770b\u51fa\uff0c\u5728\u975epoll\u6a21\u5f0f\u4e0b\uff0cio_uring\u5728IO\u5ef6\u8fdf\u548cIOPS\u4e0a\u90fd\u6709\u4e86\u4e9b\u8bb8\u7684\u63d0\u5347\uff0c\u63d0\u5347\u6548\u679c\u4f3c\u4e4e\u5e76\u4e0d\u5927\u3002\u5f53\u5f00\u542f\u4e86iopoll\u548csqpoll\u7684\u60c5\u51b5\u4e0b\uff0c\u5185\u6838\u8fdb\u7a0b\u4f1a\u540c\u65f6\u5bf9\u63d0\u4ea4\u961f\u5217\u548c\u5757\u8bbe\u5907\u9a71\u52a8\u505a\u8f6e\u8be2\uff0c\u6b64\u65f6\u80fd\u591f\u8fbe\u5230\u6700\u4f73\u7684IO\u6027\u80fd\u3002\u4ece\u6570\u636e\u4e2d\u6211\u4eec\u53ef\u4ee5\u770b\u51fa\uff0c\u5f53\u5f00\u542f\u4e86poll\u6a21\u5f0f\u540e\uff0cio_uring\u5728\u5ef6\u8fdf\u548cIOPS\u4e0a\u7684\u8868\u73b0\u5df2\u7ecf\u8fdc\u8fdc\u8d85\u8d8a\u4e86AIO\uff0c\u5e76\u4e14\u5df2\u7ecf\u53ef\u4ee5\u5ab2\u7f8espdk\u4e86\uff0c\u7279\u522b\u662f\u5728\u9ad8QD\uff08Queue depth\uff0c\u4e00\u6b21\u6027\u5411\u8bbe\u5907\u53d1\u9001\u591a\u4e2aIO\u8bf7\u6c42\uff09\u7684\u60c5\u51b5\u4e0b\uff0c\u751a\u81f3\u6709\u8d76\u8d85\u7684\u8d8b\u52bf\u3002<\/p>\n

\u963f\u91cc\u4e91\u7684\u56e2\u961f\u5bf9io_uring\u7684\u6027\u80fd\u4e5f\u505a\u4e86\u6d4b\u8bc4\uff0c\u5176\u6d4b\u8bc4\u73af\u5883\u4e3a\uff1aecs.i2.2xlarge\uff0c8 vCPU 64 GiB\uff0cI2 \u672c\u5730\u5b58\u50a8 1788 GiB\u3002\u6d4b\u8bc4\u7ed3\u679c\u663e\u793a\uff0c\u5728\u8fdb\u884c\u987a\u5e8f\u8bfb\u5199\u7684\u60c5\u51b5\u4e0b\uff0cio_uring\u6027\u80fd\u63d0\u5347\u660e\u663e\uff0c\u53ef\u8fbe\u5230160% ~ 170%\uff1b\u5728\u8fdb\u884c\u968f\u673a\u8bfb\u5199\u65f6\uff0c\u6027\u80fd\u63d0\u5347\u53ef\u8fbe\u523030% ~ 150%\u3002\u6d4b\u8bc4\u6570\u636e\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n

4k\u987a\u5e8f\u8bfb\u53d6\uff1a<\/p>\n

4k\u987a\u5e8f\u5199\u5165\uff1a<\/p>\n

4k\u968f\u673a\u8bfb\u53d6\uff1a<\/p>\n

4k\u968f\u673a\u5199\u5165\uff1a<\/p>\n

4.1.2 \u666e\u901a\u673a\u68b0\u786c\u76d8
\n\u5728\u901f\u5ea6\u6bd4\u8f83\u6162\u7684\u673a\u68b0\u786c\u76d8\u4e0a\uff0cio_uring\u6027\u80fd\u63d0\u5347\u4e0d\u660e\u663e\u3002\u7b14\u8005\u5728generic X86\u7684PC\u4e0b\u4f7f\u7528fio\u6d4b\u8bd5\u7ec4\u4ef6\u5bf9io_uring\u7684\u6027\u80fd\u8fdb\u884c\u4e86\u6d4b\u8bd5\uff0c\u6d4b\u8bd5\u4e2d\u6240\u4f7f\u7528\u5230\u7684\u5b58\u50a8\u5668\u4e3a\u666e\u901a\u7684\u673a\u68b0\u786c\u76d8\uff0c\u6d4b\u8bd5\u65b9\u5f0f\u4e3a\u8fdb\u884c4k\u7684\u968f\u673a\u8bfb\u64cd\u4f5c\uff0c\u6d4b\u8bd5\u7ed3\u679c\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n

Interface QD Polled Latency IOPS
\nsync 1 0 10.1msec 131
\nsync 4 0 9.8msec 132
\nsync 16 0 10.3msec 130
\nio_uring 1 1 9.7msec 133
\nio_uring 4 1 20.1msec 201
\nio_uring 16 1 55.7msec 286
\nio_uring 1 0 9.9msec 132
\nio_uring 4 0 20.2msec 205
\nio_uring 16 0 55.5msec 290
\n\u4ece\u7ed3\u679c\u4e2d\u53ef\u4ee5\u770b\u51fa\uff0c\u7531\u4e8e\u540c\u6b65IO\u65b9\u5f0f\u5e76\u4e0d\u652f\u6301\u591a\u8bf7\u6c42\u961f\u5217\uff0c\u56e0\u6b64\u5ef6\u8fdf\u548cIOPS\u57fa\u672c\u6ca1\u4ec0\u4e48\u53d8\u5316\u3002\u800cio_uring\u968f\u7740QD\u7684\u589e\u52a0\uff0cIOPS\u5f97\u5230\u4e86\u663e\u8457\u7684\u63d0\u5347\uff0c\u5728QD\u4e3a16\u7684\u65f6\u5019\u66f4\u662f\u63d0\u5347\u4e86\u4e00\u500d\u4ee5\u4e0a\uff0c\u4f46\u662f\u5ef6\u8fdf\u4e5f\u4e0a\u5347\u5230\u4e8650\u6beb\u79d2\u3002\u540c\u65f6\uff0c\u662f\u5426\u5904\u4e8epoll\u6a21\u5f0f\u5bf9\u4e8e\u786c\u76d8IO\u57fa\u672c\u4e0a\u6ca1\u6709\u4ea7\u751f\u5f71\u54cd\u3002<\/p>\n

\u5728\u5bf9\u6162\u901f\u7684\u673a\u68b0\u786c\u76d8\u8fdb\u884cIO\u7684\u65f6\u5019\uff0c\u6027\u80fd\u7684\u74f6\u9888\u662f\u4f4e\u901f\u7684\u78c1\u76d8IO\u3002\u56e0\u6b64\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u76f8\u6bd4\u4e8e\u78c1\u76d8\u7684IO\u901f\u5ea6\uff0c\u7cfb\u7edf\u8c03\u7528\u4ee5\u53ca\u4e2d\u65ad\u5bf9\u6027\u80fd\u9020\u6210\u7684\u5f71\u54cd\u57fa\u672c\u4e0a\u53ef\u4ee5\u5ffd\u7565\u4e0d\u8ba1\uff0c\u6240\u4ee5\u5728QD\u4e3a1\u7684\u65f6\u5019io_uring\u4e0e\u666e\u901a\u6a21\u5f0f\u7684IO\u6027\u80fd\u6ca1\u6709\u4ec0\u4e48\u5dee\u522b\u3002\u5728QD\u63d0\u9ad8\u7684\u60c5\u51b5\u4e0b\uff0c\u786c\u76d8\u7684IOPS\u5f97\u5230\u4e86\u63d0\u5347\uff0cIO\u5e26\u5bbd\u660e\u663e\u4e0a\u5347\uff0c\u4f46\u662f\u7531\u4e8e\u673a\u68b0\u786c\u76d8\u7684\u786c\u4ef6\u6027\u80fd\u8f83\u5dee\uff0c\u5bfc\u81f4\u5728\u540c\u65f6\u5904\u7406\u591a\u4e2aIO\u8bf7\u6c42\u65f6\u4ea7\u751f\u5ef6\u8fdf\u660e\u663e\u5347\u9ad8\u7684\u95ee\u9898\u3002\u8fd9\u91cc\u6211\u4eec\u53ef\u4ee5\u770b\u51fa\uff0c\u5bf9\u4e8e\u5ef6\u8fdf\u4e0d\u654f\u611f\u7684\u573a\u666f\uff0c\u4f7f\u7528io_uring\u53ef\u4ee5\u66f4\u52a0\u5145\u5206\u5730\u53d1\u6325\u673a\u68b0\u786c\u76d8\u7684IO\u6027\u80fd\uff0c\u83b7\u5f97\u8f83\u9ad8\u7684IO\u5e26\u5bbd\u3002<\/p>\n

4.2 \u7f51\u7edc\u6027\u80fd\u6d4b\u8bd5
\n\u7531\u4e8eio_uring\u673a\u5236\u672c\u8eab\u6240\u5f15\u5165\u7684\u5f00\u9500\uff0c\u5176\u5728\u7f51\u7edc\u62a5\u6587\u5904\u7406\u65b9\u9762\u51fa\u73b0\u4e86\u6027\u80fd\u9000\u5316\u7684\u95ee\u9898\u3002\u7f51\u7edcIO\u76f8\u6bd4\u4e8e\u5b58\u50a8\u5668IO\u4e0d\u592a\u4e00\u6837\uff0c\u7f51\u7edcIO\u672c\u8d28\u4e0a\u5e94\u8be5\u662f\u5c5e\u4e8eCPU\u5bc6\u96c6\u578b\u573a\u666f\uff0c\u5373\u5f71\u54cd\u7f51\u7edc\u541e\u5410\u91cf\u7684\u662fCPU\u7684\u6027\u80fd\u3002\u56e0\u6b64\u5bf9\u4e8e\u7f51\u7edcIO\uff0cio_uring\u7684\u76ee\u6807\u5e94\u8be5\u662f\u964d\u4f4eCPU\u5f00\u9500\u3002\u4ece\u4e0a\u9762\u7684\u5206\u6790\u4e2d\u6211\u4eec\u53ef\u4ee5\u770b\u51fa\uff0c\u57fa\u4e8eio_uring\u7684\u62a5\u6587\u6536\u53d1\u80fd\u591f\u964d\u4f4e\u7cfb\u7edf\u8c03\u7528\u6b21\u6570\uff0c\u4ece\u800c\u8d77\u5230\u51cf\u5c11CPU\u5f00\u9500\u7684\u76ee\u7684\u3002\u7531\u4e8epoll\u6a21\u5f0f\u672c\u8d28\u662f\u4e00\u79cd\u727a\u7272CPU\u5f00\u9500\u6765\u6362\u53d6\u6027\u80fd\u7684\u624b\u6bb5\uff0c\u56e0\u6b64\u8fd9\u91cc\u53ef\u80fd\u5e76\u4e0d\u9002\u7528\uff0c\u8fd9\u91cc\u6211\u4eec\u5c31\u4e0d\u8003\u8651\u8be5\u6a21\u5f0f\u3002<\/p>\n

\u6d4b\u8bd5\u65b9\u5f0f\uff1a\u8fdb\u884cUDP\u6536\u5305\uff0c\u5176\u4e2d\u6bcf\u4e2aUDP\u62a5\u6587\u7684\u5927\u5c0f\u4e3a1k\u3002<\/p>\n

\u6a21\u5f0f \u62a5\u6587\u91cf \u8f6f\u4e2d\u65adCPU \u7528\u6237\u8fdb\u7a0bCPU CPU\u5360\u7528\u603b\u91cf
\nsync 10k\/s 37.8% 31.6% 69.4%
\nio_uring 10k\/s 44.8% 54.4% 99.2%
\n\u4ece\u6570\u636e\u4e2d\u6211\u4eec\u53ef\u4ee5\u770b\u51fa\uff0c\u4f7f\u7528io_uring\u65b9\u5f0f\u8fdb\u884c\u5f02\u6b65\u62a5\u6587\u63a5\u6536\u53cd\u800c\u9020\u6210\u4e86CPU\u7684\u5347\u9ad8\uff0c\u8fd9\u662f\u4e3a\u4ec0\u4e48\u5462\uff1f\u56e0\u4e3aio_uring\u673a\u5236\u672c\u8eab\u4e5f\u4f1a\u989d\u5916\u7684\u4ea7\u751f\u5f00\u9500\u3002\u5728\u8fdb\u884c\u5f02\u6b65\u62a5\u6587\u63a5\u6536\u65f6\uff0c\u7531\u4e8e\u64cd\u4f5c\u662f\u5f02\u6b65\u7684\uff0c\u56e0\u6b64\u5185\u6838\u4f1a\u5c06\u63a5\u6536\u64cd\u4f5c\u653e\u5230\u5f02\u6b65\u961f\u5217\u4e2d\u5e76\u542f\u52a8\u591a\u4e2a\u5de5\u4f5c\u961f\u5217\u6765\u5904\u7406\u6536\u5305\u8bf7\u6c42\uff0c\u5e76\u5c06\u6bcf\u4e2a\u62a5\u6587\u63a5\u6536\u8bf7\u6c42\u90fd\u94fe\u63a5\u5230\u5957\u63a5\u53e3\u7684poll\u961f\u5217\u4e0a\u7b49\u5f85\u62a5\u6587\u5230\u8fbe\u540e\u5524\u9192\u3002\u989d\u5916\u7684poll\u64cd\u4f5c\u662fCPU\u5347\u9ad8\u7684\u4e00\u4e2a\u539f\u56e0\uff0c\u53e6\u4e00\u4e2a\u539f\u56e0\u662f\u6fc0\u70c8\u662f\u9501\u7ade\u4e89\u3002\u4e3a\u4e86\u4fdd\u8bc1\u64cd\u4f5c\u7684\u4e00\u81f4\u6027\uff0cio_uring\u4f7f\u7528\u4e86\u5927\u91cf\u7684\u81ea\u65cb\u9501\uff0c\u5728\u591a\u4e2a\u5f02\u6b65\u8bf7\u6c42\u540c\u65f6\u8fdb\u884c\u7684\u60c5\u51b5\u4e0b\uff0c\u9501\u7ade\u4e89\u6d88\u8017\u4e86\u76f8\u5f53\u591a\u7684CPU\u3002\u7531\u6b64\u53ef\u89c1\uff0c\u5728\u7f51\u7edcIO\u65b9\u9762\uff0cio_uring\u8fd8\u5b58\u5728\u7740\u4e00\u5b9a\u7684\u4f18\u5316\u7a7a\u95f4\u3002<\/p>\n

\u4e94\u3001\u5e94\u7528\u7f16\u7a0b\u793a\u4f8b
\n5.1 liburing
\n\u76f4\u63a5\u4f7f\u7528\u7cfb\u7edf\u8c03\u7528\u6765\u8fdb\u884cio_uring\u7684\u5f00\u53d1\u8fd8\u662f\u6bd4\u8f83\u590d\u6742\u7684\uff0c\u7279\u522b\u662f\u9700\u8981\u5bf9\u5171\u4eab\u5185\u5b58\u4e2d\u7684\u73af\u5f62\u961f\u5217\u8fdb\u884c\u64cd\u4f5c\u3002\u6240\u5e78\u5f00\u6e90\u793e\u533a\u4e0a\u63d0\u4f9b\u4e86\u5c01\u88c5\u597d\u7684liburing\u5e93\uff0c\u5927\u5927\u7b80\u5316\u4e86\u5176\u4f7f\u7528\u3002\u8be5\u5e93\u6b63\u662f\u7531io_uring\u7684\u4f5c\u8005Jens Axboe\u5b9e\u73b0\u7684\uff0c\u5176\u4e3b\u8981\u63a5\u53e3\u5305\u62ec\uff1a<\/p>\n

struct io_uring ring;
\nint io_uring_queue_init(unsigned entries, struct io_uring *ring, unsigned flags);
\n1
\n2
\n\u8be5\u63a5\u53e3\u7528\u4e8eio_uring\u5b9e\u4f8b\u7684\u521d\u59cb\u5316\uff0centries\u7528\u4e8e\u6307\u5b9a\u63d0\u4ea4\u5b9e\u4f8b\u7684\u6570\u91cf\uff1bflags\u7528\u4e8e\u8bbe\u7f6e\u6807\u5fd7\uff0c\u6bd4\u5982\u7528\u4e8e\u542f\u52a8iopoll\u6a21\u5f0f\u7684IORING_SETUP_IOPOLL\uff0c\u7528\u4e8e\u542f\u52a8sqpoll\u6a21\u5f0f\u7684IORING_SETUP_SQPOLL\u7b49\u3002<\/p>\n

struct io_uring_sqe *io_uring_get_sqe(struct io_uring *ring)
\n1
\n\u83b7\u53d6\u4e00\u4e2a\u7a7a\u95f2\u7684\u63d0\u4ea4\u5b9e\u4f53\u7528\u4e8eIO\u7684\u63d0\u4ea4\u3002<\/p>\n

static inline void io_uring_prep_read(struct io_uring_sqe *sqe, int fd,
\nvoid *buf, unsigned nbytes, off_t offset)
\n1
\n2
\n\u8be5\u51fd\u6570\u4e3a\u63d0\u4ea4\u5b9e\u4f53\u521d\u59cb\u5316\u7684\u5c01\u88c5\uff0c\u4f7f\u7528\u63d0\u4f9b\u7684\u53c2\u6570\u5c06\u63d0\u4ea4\u5b9e\u4f53\u521d\u59cb\u5316\u4e3a\u201c\u8bfb\u201d\u64cd\u4f5c\u3002\u9664\u6b64\u4e4b\u5916\uff0c\u8fd8\u8981write\/send\/recv\/…\u7b49\u64cd\u4f5c\u7684\u5c01\u88c5\u51fd\u6570\uff0c\u7b80\u5316\u4e86\u4ee3\u7801\u7684\u7f16\u5199\u3002<\/p>\n

static inline void io_uring_sqe_set_data(struct io_uring_sqe *sqe, void *data)
\nstatic inline void *io_uring_cqe_get_data(const struct io_uring_cqe *cqe)
\n1
\n2
\n\u4e3a\u63d0\u4ea4\u5b9e\u4f53\u8bbe\u7f6e\uff08\u83b7\u53d6\uff09\u79c1\u6709\u6570\u636e\uff0c\u8be5\u6570\u636e\u4e3a\u81ea\u5b9a\u4e49\u6570\u636e\uff0c\u7528\u4e8e\u5728\u63d0\u4ea4\u5b9e\u4f53\u5b8c\u6210\u540e\uff0c\u4ece\u5b8c\u6210\u961f\u5217\u4e2d\u83b7\u53d6\u5230\u8be5\u5bf9\u8c61\u65f6\u7684\u8bc6\u522b\u7b49\u4f5c\u7528\u3002<\/p>\n

int io_uring_submit(struct io_uring *ring)
\n1
\n\u5c06\u63d0\u4ea4\u961f\u5217\u4e2d\u7684SQE\u63d0\u4ea4\u7ed9\u5185\u6838\u5904\u7406\u3002\u5982\u679c\u5f00\u542f\u4e86SQPOLL\u6a21\u5f0f\uff0c\u8be5\u51fd\u6570\u4e0d\u4e00\u5b9a\u4f1a\u9677\u5165\u7cfb\u7edf\u8c03\u7528\uff0c\u53ea\u6709\u5728\u68c0\u67e5\u5230\u5185\u6838\u8fdb\u7a0b\u6ca1\u6709\u8fd0\u884c\u7684\u60c5\u51b5\u4e0b\u624d\u4f1a\u4ea7\u751f\u7cfb\u7edf\u8c03\u7528\u3002<\/p>\n

static inline int io_uring_peek_cqe(struct io_uring *ring,
\nstruct io_uring_cqe **cqe_ptr)
\nstatic inline int io_uring_wait_cqe(struct io_uring *ring,
\nstruct io_uring_cqe **cqe_ptr)
\n1
\n2
\n3
\n4
\n\u4ece\u5b8c\u6210\u961f\u5217\u4e2d\u83b7\u53d6\u5b8c\u6210\u5b9e\u4f8b\uff0c\u63d0\u4f9b\u4e86\u963b\u585e\u548c\u975e\u963b\u585e\u4e24\u4e2a\u7248\u672c\u3002<\/p>\n

5.2 \u7f16\u7a0b\u793a\u4f8b
\n\u4e0b\u9762\u4ee5UDP\u6536\u5305\u4e3a\u4f8b\uff0c\u6765\u6f14\u793a\u5982\u4f55\u4f7f\u7528liburing\u6765\u8fdb\u884c\u5f02\u6b65IO\u7684\u5b9e\u73b0\u3002<\/p>\n

#include <stdio.h>
\n#include <fcntl.h>
\n#include <string.h>
\n#include <stdlib.h>
\n#include <unistd.h>
\n#include <assert.h>
\n#include <errno.h>
\n#include <inttypes.h>
\n#include <sys\/types.h>
\n#include <sys\/stat.h>
\n#include <sys\/ioctl.h>
\n#include <sys\/socket.h>
\n#include <arpa\/inet.h>
\n#include <sys\/types.h><\/p>\n

#include “liburing.h”<\/p>\n

#define MAX_PKT_SIZE 1500
\n#define MAX_PKT_COUNT 10<\/p>\n

static void submit_recv(struct io_uring *ring, int sockfd, void *data)
\n{
\nstruct io_uring_sqe *sqe = io_uring_get_sqe(ring);
\nif (!sqe)
\nreturn;<\/p>\n

io_uring_prep_recv(sqe, sockfd, data, MAX_PKT_SIZE, 0);
\nio_uring_sqe_set_data(sqe, data);
\n}<\/p>\n

static void submit_all_recv(struct io_uring *ring, int sockfd)
\n{
\nstruct io_uring_sqe *sqe;
\nvoid *data;<\/p>\n

\/\/\u83b7\u53d6\u7a7a\u95f2\u7684sqe
\nwhile ((sqe = io_uring_get_sqe(ring))) {
\ndata = malloc(MAX_PKT_SIZE);
\n\/\/\u5c06sqe\u521d\u59cb\u5316\u4e3arecv\u64cd\u4f5c
\nio_uring_prep_recv(sqe, sockfd, data, MAX_PKT_SIZE, 0);
\n\/\/\u8bbe\u7f6esqe\u7684\u79c1\u6709\u6570\u636e\uff0c\u65b9\u4fbf\u6211\u4eec\u5728\u64cd\u4f5c\u5b8c\u6210\u540e\u83b7\u53d6\u5230\u5176\u4e2d\u7684\u62a5\u6587\u6570\u636e
\nio_uring_sqe_set_data(sqe, data);
\n}
\n}<\/p>\n

static int do_recv(struct io_uring *ring, int sockfd)
\n{
\nstruct io_uring_cqe *cqe;
\nvoid *data;
\nint count;<\/p>\n

\/\/\u5bf9\u63d0\u4ea4\u6570\u7ec4\u4e2d\u6240\u6709\u7a7a\u95f2\u7684\u63d0\u4ea4\u5b9e\u4f53\u8fdb\u884c\u521d\u59cb\u5316\uff0c\u5e76\u653e\u5230\u63d0\u4ea4\u961f\u5217
\nsubmit_all_recv(ring, sockfd);
\n\/\/\u5c06\u63d0\u4ea4\u961f\u5217\u4e2d\u7684\u8bf7\u6c42\u63d0\u4ea4\u7ed9\u5185\u6838\u5904\u7406
\nio_uring_submit(ring);
\ncount = 0;<\/p>\n

while (true) {
\n\/\/\u4ece\u5b8c\u6210\u961f\u5217\u4e2d\u53d6\u51fa\u4e00\u4e2a\u5b9e\u4f8b\uff0c\u8fd4\u56de\u975e0\u7684\u8bdd\u4ee3\u8868\u5b8c\u6210\u961f\u5217\u4e2d\u6ca1\u6709\u53ef\u53d6\u5b9e\u4f8b
\nif (io_uring_peek_cqe(ring, &cqe)) {
\n\/\/\u8fdb\u884c\u4e00\u6b21\u63d0\u4ea4\u64cd\u4f5c\uff0c\u5c06\u63d0\u4ea4\u961f\u5217\u4e2d\u7684\u8bf7\u6c42\u6279\u91cf\u63d0\u4ea4\u7ed9\u5185\u6838\u5904\u7406
\nio_uring_submit(ring);
\n\/\/\u4ee5\u963b\u585e\u7684\u65b9\u5f0f\u7b49\u5f85\u5b8c\u6210\u961f\u5217\u4e2d\u5b58\u5728\u53ef\u7528\u5b9e\u4f8b
\nio_uring_wait_cqe(ring, &cqe);
\n}
\nif (!cqe) {
\nfprintf(stderr, “io_uring_get_sqe failed\\n”);
\ncontinue;
\n}
\n\/\/\u83b7\u53d6\u5b8c\u6210\u5b9e\u4f8b\u4e2d\u4e4b\u524d\u8bbe\u7f6e\u7684\u79c1\u6709\u6570\u636e
\ndata = io_uring_cqe_get_data(cqe);
\ncount++;
\nif (!(count % 1000))
\nprintf(“recved packet count: %d, queue len:%d\\n”, count, io_uring_sq_ready(ring));
\n\/\/\u5c06\u5b8c\u6210\u5b9e\u4f8b\u6807\u8bc6\u4e3a\u201c\u5b8c\u6210\u5904\u7406\u201d\uff0c\u5176\u5bf9\u5e94\u7684\u63d0\u4ea4\u5b9e\u4f8b\u53ef\u4ee5\u88ab\u4f7f\u7528\u4e86
\nio_uring_cqe_seen(ring, cqe);
\n\/\/\u7ee7\u7eed\u8fdb\u884c\u8bf7\u6c42\u7684\u63d0\u4ea4\u3002\u8fd9\u91cc\u4f7f\u7528\u4e4b\u524d\u5206\u914d\u597d\u7684data\uff0c\u907f\u514d\u91cd\u590d\u7684\u5185\u5b58\u5206\u914d
\nsubmit_recv(ring, sockfd, data);
\n}<\/p>\n

return 0;
\n}<\/p>\n

int main()
\n{
\nstruct sockaddr_in saddr;
\nstruct io_uring ring;
\nint ret, sockfd;<\/p>\n

\/\/\u521d\u59cb\u5316uring\uff0c\u8bbe\u7f6e\u63d0\u4ea4\u961f\u5217\u957f\u5ea6\u4e3a10
\nret = io_uring_queue_init(10, &ring, 0);
\nif (ret < 0)
\n{
\nperror(“queue_init”);
\ngoto err;
\n}<\/p>\n

\/\/\u521d\u59cb\u5316UDP\u5957\u63a5\u5b57
\nmemset(&saddr, 0, sizeof(saddr));
\nsaddr.sin_family = AF_INET;
\nsaddr.sin_addr.s_addr = htonl(INADDR_ANY);
\nsaddr.sin_port = htons(8080);
\nsockfd = socket(AF_INET, SOCK_DGRAM, 0);
\nret = bind(sockfd, (struct sockaddr *)&saddr, sizeof(saddr));
\nif (ret < 0)
\n{
\nperror(“bind”);
\ngoto err;
\n}<\/p>\n

\/\/\u5f00\u59cb\u62a5\u6587\u63a5\u6536
\ndo_recv(&ring, sockfd);
\nerr:
\nreturn -1;
\n}
\n1
\n2
\n3
\n4
\n5
\n6
\n7
\n8
\n9
\n10
\n11
\n12
\n13
\n14
\n15
\n16
\n17
\n18
\n19
\n20
\n21
\n22
\n23
\n24
\n25
\n26
\n27
\n28
\n29
\n30
\n31
\n32
\n33
\n34
\n35
\n36
\n37
\n38
\n39
\n40
\n41
\n42
\n43
\n44
\n45
\n46
\n47
\n48
\n49
\n50
\n51
\n52
\n53
\n54
\n55
\n56
\n57
\n58
\n59
\n60
\n61
\n62
\n63
\n64
\n65
\n66
\n67
\n68
\n69
\n70
\n71
\n72
\n73
\n74
\n75
\n76
\n77
\n78
\n79
\n80
\n81
\n82
\n83
\n84
\n85
\n86
\n87
\n88
\n89
\n90
\n91
\n92
\n93
\n94
\n95
\n96
\n97
\n98
\n99
\n100
\n101
\n102
\n103
\n104
\n105
\n106
\n107
\n108
\n109
\n110
\n111
\n112
\n113
\n114
\n115
\n\u53ef\u4ee5\u770b\u51fa\u4f7f\u7528\u8fd8\u662f\u6bd4\u8f83\u7b80\u6d01\u7684\uff0c\u7528\u6237\u4e5f\u53ef\u4ee5\u5bf9liburing\u63a5\u53e3\u8fdb\u884c\u4e8c\u6b21\u5c01\u88c5\u4ee5\u8fbe\u5230\u66f4\u52a0\u7b80\u6d01\u7684\u76ee\u7684\u3002<\/p>\n

\u516d\u3001\u57fa\u4e8eio_uring\u7684\u96f6\u62f7\u8d1d\u5c55\u671b
\n6.1 MSG_ZEROCOPY
\nMSG_ZEROCOPY\u662f\u5185\u6838\u4e2d\u73b0\u6709\u7684\u7f51\u7edc\u62a5\u6587\u96f6\u62f7\u8d1d\u6280\u672f\uff0c\u8fd9\u4e2a\u6240\u8c13\u7684\u96f6\u62f7\u8d1d\u6280\u672f\uff0c\u65e0\u8bba\u662f\u5b9e\u73b0\u8fd8\u662f\u53d6\u5f97\u7684\u6548\u679c\u90fd\u6709\u4e9b\u5dee\u5f3a\u4eba\u610f\u3002\u8be5\u6280\u672f\u662f\u5728\u4e09\u5e74\u524d\u63d0\u51fa\uff0c\u5b83\u53ef\u4ee5\u5e94\u7528\u4e8e\u5404\u79cd\u5e38\u7528\u7f51\u7edc\u534f\u8bae\u7684\u96f6\u62f7\u8d1d\u6536\u53d1\uff0c\u6bd4\u5982UDP\u3001TCP\u3001raw\u4ee5\u53capacket\u7b49\uff0c\u4f7f\u7528\u4e5f\u5f88\u65b9\u4fbf\uff0c\u53ea\u9700\u8981\u6307\u5b9a\u5bf9\u5e94\u7684\u5957\u63a5\u5b57\u6807\u5fd7\u5373\u53ef\u3002\u4ee5\u53d1\u5305\u4e3a\u4f8b\uff0c\u5176\u5b9e\u73b0\u903b\u8f91\u5982\u4e0b\u56fe\u6240\u793a\uff1a<\/p>\n

 <\/p>\n

\u9996\u5148\uff0c\u5728\u521b\u5efa\u5957\u63a5\u53e3\u7684\u65f6\u5019\uff0c\u4e3a\u5957\u63a5\u53e3\u6307\u5b9a\u96f6\u62f7\u8d1d\u7684\u6807\u5fd7SO_ZEROCOPY\uff0c\u4ee3\u8868\u540e\u9762\u90fd\u7528\u96f6\u62f7\u8d1d\u7684\u65b9\u5f0f\u8fdb\u884c\u62a5\u6587\u53d1\u9001\uff1a<\/p>\n

setsockopt(fd, SOL_SOCKET, SO_ZEROCOPY, &one, sizeof(one))
\n1
\n\u7136\u540e\uff0c\u4f7f\u7528\u6211\u4eec\u5e73\u65f6\u719f\u6089\u7684send()\u6216\u8005sendmsg()\u8fdb\u884c\u6d88\u606f\u7684\u53d1\u9001\u5373\u53ef\uff0c\u53d1\u9001\u7684\u65f6\u5019\u8981\u6307\u5b9aMSG_ZEROCOPY\u6807\u5fd7\uff0c\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n

ret = send(fd, buf, sizeof(buf), MSG_ZEROCOPY);
\n1
\n\u62a5\u6587\u7684\u53d1\u9001\u8fc7\u7a0b\u662f\u5f02\u6b65\u7684\uff0c\u5f53send()\u7cfb\u7edf\u8c03\u7528\u8fd4\u56de\u7684\u65f6\u5019\uff0c\u6211\u4eec\u5e76\u4e0d\u786e\u5b9a\u5f53\u524d\u62a5\u6587\u5df2\u7ecf\u88ab\u7f51\u5361\u987a\u5229\u7684\u53d1\u9001\u51fa\u53bb\u4e86\uff0c\u56e0\u6b64\u8fd8\u9700\u8981\u4e00\u4e2a\u673a\u5236\u6765\u5b8c\u6210\u8fd9\u9879\u5de5\u4f5c\u3002MSG_ZEROCOPY\u5229\u7528\u4e86\u5957\u63a5\u53e3\u7684\u201c\u9519\u8bef\u961f\u5217\u201d\u6765\u5b9e\u73b0\u8fd9\u4e00\u673a\u5236\uff0c\u5373\u5f53\u62a5\u6587\u53d1\u9001\u5b8c\u6210\u4e86\uff0c\u5185\u6838\u4f1a\u5f80\u5957\u63a5\u53e3\u7684\u201c\u9519\u8bef\u961f\u5217\u201d\u4e2d\u653e\u4e00\u6761\u6d88\u606f\uff0c\u7528\u6237\u68c0\u6d4b\u5230\u8be5\u6d88\u606f\u540e\u624d\u53ef\u4ee5\u91cd\u65b0\u4f7f\u7528\u8fd9\u4e2a\u62a5\u6587\u7f13\u51b2\u533a\u3002\u56e0\u6b64\uff0c\u7528\u6237\u7a0b\u5e8f\u9700\u8981\u4e3b\u52a8\u5728\u5f53\u524d\u5957\u63a5\u53e3\u4e0a\u8fdb\u884cpoll()\u64cd\u4f5c\uff0c\u4ee5\u7b49\u5f85\u6d88\u606f\u7684\u5230\u6765\uff0c\u7136\u540e\u4f7f\u7528recvmsg()\u5c06\u8be5\u6d88\u606f\u4ece\u9519\u8bef\u961f\u5217\u4e2d\u53d6\u51fa\uff0c\u5224\u65ad\u5176\u662f\u6211\u4eec\u5173\u6ce8\u7684\u6d88\u606f\u540e\uff0c\u518d\u7ee7\u7eed\u62a5\u6587\u7684\u53d1\u9001\u3002\u8fd9\u4e2a\u8fc7\u7a0b\u7684\u4ee3\u7801\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n

pfd.fd = fd;
\npfd.events = 0;
\nif (poll(&pfd, 1, -1) != 1 || pfd.revents & POLLERR == 0)
\nerror(1, errno, “poll”);<\/p>\n

ret = recvmsg(fd, &msg, MSG_ERRQUEUE);
\nif (ret == -1)
\nerror(1, errno, “recvmsg”);<\/p>\n

read_notification(msg);
\n1
\n2
\n3
\n4
\n5
\n6
\n7
\n8
\n9
\n10
\n\u53ef\u4ee5\u770b\u51fa\uff0c\u867d\u7136\u5185\u6838\u907f\u514d\u4e86\u5185\u5b58\u62f7\u8d1d\uff0c\u4f46\u662f\u76f8\u6bd4\u4e8e\u4f20\u7edf\u7684\u62a5\u6587\u53d1\u9001\uff0c\u8be5\u65b9\u5f0f\u591a\u4e86\u4e24\u6b21\u7cfb\u7edf\u8c03\u7528\u3002\u7efc\u5408\u8861\u91cf\uff0c\u4e0d\u4e00\u5b9a\u4f1a\u53d6\u5f97\u6027\u80fd\u7684\u63d0\u5347\u3002\u6839\u636e\u4f5c\u8005\u7684\u63cf\u8ff0\uff0c\u5f53\u62a5\u6587\u5927\u5c0f\u5927\u4e8e10k\u7684\u65f6\u5019\uff0c\u53ef\u80fd\u624d\u4f1a\u770b\u5230\u6548\u679c\u3002<\/p>\n

6.2 io_uring\u96f6\u62f7\u8d1d
\n\u4ece\u4e0a\u9762\u7684\u673a\u5236\u6211\u4eec\u53ef\u4ee5\u770b\u51fa\u6765\uff0cio_uring\u662f\u4e00\u79cd\u901a\u7528\u7684\u5f02\u6b65IO\u673a\u5236\uff0c\u5176\u4e0d\u9650\u4e8e\u5757\u8bbe\u5907\u7684IO\uff0c\u5e38\u89c4\u7684\u57fa\u4e8e\u6587\u4ef6\u7684IO\u90fd\u53ef\u4ee5\u4f7f\u7528\u3002MSG_ZEROCOPY\u96f6\u62f7\u8d1d\u6280\u672f\u7684\u74f6\u9888\u5c31\u5728\u4e8e\u5176\u901a\u77e5\u673a\u5236\u5f15\u5165\u4e86\u4e0d\u5fc5\u8981\u7684\u7cfb\u7edf\u8c03\u7528\uff0c\u5982\u679c\u4f7f\u7528io_uring\u6765\u5b9e\u73b0\u96f6\u62f7\u8d1d\uff0c\u90a3\u4e48\u901a\u77e5\u7684\u95ee\u9898\u5c31\u8fce\u5203\u800c\u89e3\uff0c\u56e0\u4e3aio_uring\u672c\u8eab\u5c31\u63d0\u4f9b\u4e86\u4f7f\u7528\u5b8c\u6210\u961f\u5217\u6765\u8fdb\u884c\u901a\u77e5\u7684\u529f\u80fd\u3002<\/p>\n

\u5bf9\u4e8e\u8fd9\u4e2a\u601d\u8def\uff0c\u793e\u533a\u4e0a\u7684Jonathan Lemon\uff08MSG_ZEROCOPY\u7684\u7ef4\u62a4\u8005\uff09\u5df2\u7ecf\u5728\u90ae\u4ef6\u7cfb\u7edf\u4e0a\u63d0\u8fc7\u4e86\uff08\u8fd8\u6ca1\u5b9e\u73b0\uff0c\u4e0d\u77e5\u9053\u6709\u6ca1\u6709\u5728\u5e72\u6d3b\uff09\uff1a<\/p>\n

MSG_ZEROCOPY_FIXED\uff0cio_uring-only sendmsg + recvmsg zerocopy<\/p>\n

\u6839\u636e\u793e\u533a\u4e0a\u7684\u8ba8\u8bba\uff0c\u4ed6\u4eec\u662f\u60f3\u57fa\u4e8eio_uring\u5b9e\u73b0\u4e00\u4e2a\u771f\u00b7\u96f6\u62f7\u8d1d\u6280\u672f\uff0c\u80fd\u591f\u771f\u6b63\u610f\u4e49\u4e0a\u4f7f\u5f97\u7f51\u7edc\u62a5\u6587\u7684\u63a5\u6536\u548c\u53d1\u9001\u8fc7\u7a0b\u4e2d\u4e0d\u4ea7\u751f\u6570\u636e\u62f7\u8d1d\uff1a\u6536\u5305\u9636\u6bb5\uff0c\u7533\u8bf7\u4e00\u5757\u7528\u6237\u6001\u5171\u4eab\u5185\u5b58\uff0c\u7f51\u5361\u6536\u5230\u62a5\u6587\u540e\u901a\u8fc7DMA\u76f4\u63a5\u5c06\u62a5\u6587\u4f20\u9012\u7ed9\u7528\u6237\u6001\uff1b\u53d1\u5305\u9636\u6bb5\uff0c\u57fa\u4e8eio_uring\u7684ringBuf\uff0c\u76f4\u63a5\u5c06\u7528\u6237\u6001\u7684\u62a5\u6587\u6570\u636e\u4f20\u9012\u7ed9\u7f51\u5361\u786c\u4ef6\uff0c\u5e76\u901a\u8fc7\u5b8c\u6210\u961f\u5217\u6765\u5b9e\u73b0\u5b8c\u6210\u6d88\u606f\u7684\u901a\u77e5\u3002\u8be5\u65b9\u6848\u5728\u6280\u672f\u4e0a\u8fd8\u5b58\u5728\u4e00\u5b9a\u7684\u96be\u70b9\uff0c\u53ef\u80fd\u8fd8\u9700\u8981\u4e00\u5b9a\u7684\u65f6\u95f4\u624d\u80fd\u9762\u5411\u5927\u4f17\u3002\u53ef\u4ee5\u60f3\u8c61\u5f97\u5230\uff0c\u5f53\u8be5\u65b9\u6848\u5b9e\u73b0\u7684\u65f6\u5019\uff0c\u7f51\u7edc\u6027\u80fd\u5c06\u83b7\u5f97\u8fdb\u4e00\u6b65\u7684\u63d0\u5347\u3002<\/p>\n

\u4e03\u3001\u603b\u7ed3
\n\u672c\u6587\u5bf9io_uring\u7684\u5b9e\u73b0\u539f\u7406\u4ee5\u53ca\u5176\u6240\u53d6\u5f97\u7684\u9ad8\u6027\u80fd\u8868\u73b0\u505a\u4e86\u7b80\u5355\u4ecb\u7ecd\uff0c\u53ef\u4ee5\u770b\u51fa\u8be5\u673a\u5236\u4f5c\u4e3a\u4e00\u79cd\u901a\u7528\u7684IO\u673a\u5236\u5177\u6709\u5f3a\u5927\u7684\u6f5c\u8d28\uff0c\u52bf\u5fc5\u5c06\u6210\u4e3a\u65e5\u540e\u4e3b\u6d41\u7684\u9ad8\u6027\u80fd\u5f02\u6b65IO\u89e3\u51b3\u65b9\u6848\u3002\u7279\u522b\u662fCGEL\u4e2d\u4f5c\u4e3a\u672a\u6765\u4e3b\u529b\u7248\u672c\u7684Linux v5.4\u5df2\u7ecf\u5bf9\u8be5\u673a\u5236\u63d0\u4f9b\u4e86\u5145\u5206\u7684\u652f\u6301\uff0c\u5185\u6838\u4fa7\u65e0\u9700\u505a\u4efb\u4f55\u8c03\u6574\u5373\u53ef\u4f7f\u7528\u8be5\u7279\u6027\u3002\u540c\u65f6\uff0c\u672c\u6587\u5bf9io_uring\u5728\u7f51\u7edc\u62a5\u6587\u96f6\u62f7\u8d1d\u65b9\u9762\u7684\u7814\u7a76\u73b0\u72b6\u4e5f\u505a\u4e86\u7b80\u5355\u4ecb\u7ecd\uff0c\u5177\u4f53\u80fd\u7ed9\u7f51\u7edc\u65b9\u9762\u5e26\u6765\u591a\u5927\u7684\u6027\u80fd\u63d0\u5347\uff0c\u8ba9\u6211\u4eec\u62ed\u76ee\u4ee5\u5f85\uff01<\/p>\n

\u53c2\u8003\u94fe\u63a5\uff1a\u3010\u8bd1\u3011\u9ad8\u6027\u80fd\u5f02\u6b65 IO \u2014 io_uring(Effecient IO with io_uring)
\n\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014
\n\u7248\u6743\u58f0\u660e\uff1a\u672c\u6587\u4e3aCSDN\u535a\u4e3b\u300c\u4ed9\u4eba\u638c\u5f00\u53c9\u300d\u7684\u539f\u521b\u6587\u7ae0\uff0c\u9075\u5faaCC 4.0 BY-SA\u7248\u6743\u534f\u8bae\uff0c\u8f6c\u8f7d\u8bf7\u9644\u4e0a\u539f\u6587\u51fa\u5904\u94fe\u63a5\u53ca\u672c\u58f0\u660e\u3002
\n\u539f\u6587\u94fe\u63a5\uff1ahttps:\/\/blog.csdn.net\/qq_17045267\/article\/details\/117953632<\/p>\n","protected":false},"excerpt":{"rendered":"

\u539f\u6587\u5730\u5740   \u4ed9\u4eba\u638c\u5f00\u53c9 20<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"colormag_page_container_layout":"default_layout","colormag_page_sidebar_layout":"default_layout","footnotes":""},"categories":[],"tags":[118],"class_list":["post-5481","post","type-post","status-publish","format-standard","hentry","tag-02-"],"_links":{"self":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts\/5481","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/comments?post=5481"}],"version-history":[{"count":0,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts\/5481\/revisions"}],"wp:attachment":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/media?parent=5481"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/categories?post=5481"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/tags?post=5481"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}