{"id":1398,"date":"2021-03-16T21:47:18","date_gmt":"2021-03-16T13:47:18","guid":{"rendered":"\/?p=1398"},"modified":"2021-03-16T21:47:18","modified_gmt":"2021-03-16T13:47:18","slug":"3-5-%e5%b8%b8%e8%a7%81%e7%9a%84%e6%94%b6%e9%9b%86%e5%99%a8%e4%b8%8b","status":"publish","type":"post","link":"http:\/\/xinblog.ltd\/?p=1398","title":{"rendered":"3.5.\u5e38\u89c1\u7684\u6536\u96c6\u5668(\u4e0b)"},"content":{"rendered":"<p>\u5728JDK 6u14\u540e,\u5c31\u6709G1\u7684\u51fa\u73b0,\u5728\u73b0\u5728JDK9\u4ee5\u540e,\u5df2\u7ecf\u6210\u719f\u5e76\u4e14\u6b63\u5f0f\u4f5c\u4e3aJDK\u7684\u9ed8\u8ba4\u6536\u96c6\u5668\u800c\u4f7f\u7528\u4e86<\/p>\n<p>\u5176\u7279\u70b9\u5728\u4e8e:<\/p>\n<p>1.\u5e76\u884c\u548c\u5e76\u53d1,G1\u80fd\u5145\u5206\u7684\u5229\u7528CPU:\u591a\u6838\u4e0b\u7684\u786c\u4ef6,\u5229\u7528\u591a\u6838CPU\u6765\u51cf\u5c11Stop The World<\/p>\n<p>\u6b64\u5904\u7684\u5e76\u53d1\u5e76\u884c\u6307\u7684\u662f<\/p>\n<p>\u5e76\u884c(Parallel):\u662f\u6307\u591a\u6761\u5783\u573e\u6536\u96c6\u7ebf\u7a0b\u5e76\u884c\u5de5\u4f5c,\u7528\u6237\u7ebf\u7a0b\u4ecd\u7136\u5904\u4e8e\u7b49\u5f85\u72b6\u6001<\/p>\n<p>\u5e76\u53d1(Concurrent):\u7528\u6237\u7ebf\u7a0b\u548c\u5783\u573e\u6536\u96c6\u7ebf\u7a0b\u540c\u65f6\u6267\u884c,\u7528\u6237\u7ebf\u7a0b\u7ee7\u7eed\u8fd0\u884c,\u5783\u573e\u6536\u96c6\u7a0b\u5e8f\u8fd0\u884c\u4e8e\u4e0d\u540c\u7684Cpu<\/p>\n<p>G1\u6536\u96c6\u5668\u5728GC\u7684\u8fc7\u7a0b\u4e2d\u4e5f\u662f\u901a\u8fc7\u5e76\u53d1\u7684\u65b9\u5f0f\u8ba9Java\u7a0b\u5e8f\u7ee7\u7eed\u6267\u884c<\/p>\n<p>2.\u5206\u4ee3\u56de\u6536:\u548c\u5176\u4ed6\u6536\u96c6\u5668\u4e00\u6837,\u5206\u4ee3\u56de\u6536\u7684\u6982\u5ff5\u4ecd\u7136\u88abG1\u4fdd\u7559\u7684\u4e86\u4e0b\u6765,\u867d\u7136G1\u4e0d\u7528\u5176\u4ed6\u6536\u96c6\u5668\u914d\u5408\u81ea\u5df1\u6765\u8fdb\u884c\u56de\u6536,\u4f46\u4ecd\u7136\u91c7\u7528\u4e0d\u540c\u7684\u65b9\u5f0f\u53bb\u5904\u7406\u65b0\u521b\u5efa\u7684\u5bf9\u8c61\u548c\u65e7\u5bf9\u8c61<\/p>\n<p>3.\u7a7a\u95f4\u6574\u5408,G1\u91c7\u7528\u7684\u662f\u6807\u8bb0-\u6574\u7406\u7b97\u6cd5\u5b9e\u73b0\u7684\u6536\u96c6\u5668,\u5176\u4e0d\u4f1a\u4ea7\u751f\u5185\u5b58\u7a7a\u95f4\u788e\u7247,\u6709\u5229\u4e8e\u957f\u671f\u8fd0\u884c<\/p>\n<p>4.\u53ef\u4ee5\u9884\u6d4b\u7684\u505c\u987f,\u5176\u505a\u5230\u4e86\u53ef\u4ee5\u5728\u6307\u5b9a\u957f\u5ea6\u7684M\u6beb\u79d2\u65f6\u95f4\u5185,\u8fdb\u884c\u5783\u573e\u6536\u96c6<\/p>\n<p>G1\u6700\u5927\u7684\u533a\u522b\u5c31\u662f\u4e0d\u518d\u5c06\u6574\u4e2a\u5806\u7a7a\u95f4\u5206\u4e3a\u4e86\u8001\u5e74\u4ee3\u548c\u65b0\u751f\u4ee3,\u800c\u662f\u5c06\u6574\u4e2a\u5806\u5206\u4e3a\u4e86\u5927\u5c0f\u76f8\u7b49\u7684\u72ec\u7acb\u533a\u57df,\u867d\u7136\u4fdd\u7559\u4e86\u8001\u5e74\u4ee3\u548c\u65b0\u751f\u4ee3\u7684\u6982\u5ff5,\u4f46\u662f\u4e0d\u518d\u662f\u5c06\u4e24\u8005\u7269\u7406\u9694\u79bb\u4e86,\u90fd\u662f\u4e00\u90e8\u5206Region\u7684\u96c6\u5408<\/p>\n<p><img decoding=\"async\" loading=\"lazy\" width=\"669\" height=\"322\" class=\"wp-image-1399\" src=\"\/wp-content\/uploads\/2021\/03\/unnamed-file-758.png\" alt=\"\u56fe\u7247\" srcset=\"http:\/\/xinblog.ltd\/wp-content\/uploads\/2021\/03\/unnamed-file-758.png 669w, http:\/\/xinblog.ltd\/wp-content\/uploads\/2021\/03\/unnamed-file-758-300x144.png 300w\" sizes=\"(max-width: 669px) 100vw, 669px\" \/><\/p>\n<p>region \u7684\u5927\u5c0f\u662f\u4e00\u81f4\u7684\uff0c\u6570\u503c\u662f\u5728 1M \u5230 32M \u5b57\u8282\u4e4b\u95f4\u7684\u4e00\u4e2a 2 \u7684\u5e42\u503c\u6570\uff0cJVM \u4f1a\u5c3d\u91cf\u5212\u5206 2048 \u4e2a\u5de6\u53f3\u3001\u540c\u7b49\u5927\u5c0f\u7684 region<\/p>\n<p>\u5728 G1 \u5b9e\u73b0\u4e2d\uff0c\u5e74\u4ee3\u662f\u4e2a\u903b\u8f91\u6982\u5ff5\uff0c\u5177\u4f53\u4f53\u73b0\u5728\uff0c\u4e00\u90e8\u5206 region \u662f\u4f5c\u4e3a Eden\uff0c\u4e00\u90e8\u5206\u4f5c\u4e3a Survivor\uff0c\u9664\u4e86\u610f\u6599\u4e4b\u4e2d\u7684 Old region\uff0cG1 \u4f1a\u5c06\u8d85\u8fc7 region 50% \u5927\u5c0f\u7684\u5bf9\u8c61\uff08\u5728\u5e94\u7528\u4e2d\uff0c\u901a\u5e38\u662f byte \u6216 char \u6570\u7ec4\uff09\u5f52\u7c7b\u4e3a Humongous \u5bf9\u8c61\uff0c\u5e76\u653e\u7f6e\u5728\u76f8\u5e94\u7684 region \u4e2d\u3002\u903b\u8f91\u4e0a\uff0cHumongous region \u7b97\u662f\u8001\u5e74\u4ee3\u7684\u4e00\u90e8\u5206\uff0c\u56e0\u4e3a\u590d\u5236\u8fd9\u6837\u7684\u5927\u5bf9\u8c61\u662f\u5f88\u6602\u8d35\u7684\u64cd\u4f5c\uff0c\u5e76\u4e0d\u9002\u5408\u65b0\u751f\u4ee3 GC \u7684\u590d\u5236\u7b97\u6cd5\u3002<\/p>\n<p>\u5bf9\u4e8eregion\u5927\u5c0f\u7684\u8c03\u6574,\u53ef\u4ee5\u4f7f\u7528\u5982\u4e0b\u7684\u53c2\u6570<\/p>\n<p>-XX:G1HeapRegionSize=&lt;N, \u4f8b\u598216&gt;M<\/p>\n<p>\u5728\u65b0\u751f\u4ee3\uff0cG1 \u91c7\u7528\u7684\u4ecd\u7136\u662f\u5e76\u884c\u7684\u590d\u5236\u7b97\u6cd5\uff0c\u6240\u4ee5\u540c\u6837\u4f1a\u53d1\u751f Stop-The-World \u7684\u6682\u505c\u3002\u5728\u8001\u5e74\u4ee3\uff0c\u5927\u90e8\u5206\u60c5\u51b5\u4e0b\u90fd\u662f\u5e76\u53d1\u6807\u8bb0\uff0c\u800c\u6574\u7406\uff08Compact\uff09\u5219\u662f\u548c\u65b0\u751f\u4ee3 GC \u65f6\u634e\u5e26\u8fdb\u884c\uff0c\u5e76\u4e14\u4e0d\u662f\u6574\u4f53\u6027\u7684\u6574\u7406\uff0c\u800c\u662f\u589e\u91cf\u8fdb\u884c\u7684\u3002<\/p>\n<p>\u5bf9\u4e8e G1 \u6765\u8bf4\uff1a<\/p>\n<p>Minor GC \u4ecd\u7136\u5b58\u5728\uff0c\u867d\u7136\u5177\u4f53\u8fc7\u7a0b\u4f1a\u6709\u533a\u522b\uff0c\u4f1a\u6d89\u53ca Remembered Set \u7b49\u76f8\u5173\u5904\u7406\u3002\u8001\u5e74\u4ee3\u56de\u6536\uff0c\u5219\u662f\u4f9d\u9760 Mixed GC\u3002<\/p>\n<p>\u5e76\u53d1\u6807\u8bb0\u7ed3\u675f\u540e\uff0cJVM \u5c31\u6709\u8db3\u591f\u7684\u4fe1\u606f\u8fdb\u884c\u5783\u573e\u6536\u96c6\uff0cMixed GC \u4e0d\u4ec5\u540c\u65f6\u4f1a\u6e05\u7406 Eden\u3001Survivor \u533a\u57df\uff0c\u800c\u4e14\u8fd8\u4f1a\u6e05\u7406\u90e8\u5206 Old \u533a\u57df\u3002\u53ef\u4ee5\u901a\u8fc7\u8bbe\u7f6e\u4e0b\u9762\u7684\u53c2\u6570\uff0c\u6307\u5b9a\u89e6\u53d1\u9608\u503c\uff0c\u5e76\u4e14\u8bbe\u5b9a\u6700\u591a\u88ab\u5305\u542b\u5728\u4e00\u6b21 Mixed GC \u4e2d\u7684 region \u6bd4\u4f8b\u3002<\/p>\n<p>\u2013XX:G1MixedGCLiveThresholdPercent<\/p>\n<p>\u2013XX:G1OldCSetRegionThresholdPercent<\/p>\n<p>\u6574\u4f53\u7684\u8fd0\u884c\u8fc7\u7a0b\u5982\u4e0b<\/p>\n<p><img decoding=\"async\" loading=\"lazy\" width=\"585\" height=\"358\" class=\"wp-image-1400\" src=\"\/wp-content\/uploads\/2021\/03\/unnamed-file-759.png\" alt=\"\u56fe\u7247\" srcset=\"http:\/\/xinblog.ltd\/wp-content\/uploads\/2021\/03\/unnamed-file-759.png 585w, http:\/\/xinblog.ltd\/wp-content\/uploads\/2021\/03\/unnamed-file-759-300x184.png 300w\" sizes=\"(max-width: 585px) 100vw, 585px\" \/><\/p>\n<p>\u7136\u540e\u5c31\u662f\u00a0Remembered Set<\/p>\n<p>\u7528\u4e8e\u8bb0\u5f55\u548c\u7ef4\u62a4 region \u4e4b\u95f4\u5bf9\u8c61\u7684\u5f15\u7528\u5173\u7cfb\u3002\u4e3a\u4ec0\u4e48\u9700\u8981\u8fd9\u4e48\u505a\u5462\uff1f\u8bd5\u60f3\uff0c\u65b0\u751f\u4ee3 GC \u662f\u590d\u5236\u7b97\u6cd5\uff0c\u4e5f\u5c31\u662f\u8bf4\uff0c\u7c7b\u4f3c\u5bf9\u8c61\u4ece Eden \u6216\u8005 Survivor \u5230 to \u533a\u57df\u7684\u201c\u79fb\u52a8\u201d\uff0c\u5176\u5b9e\u662f\u201c\u590d\u5236\u201d\uff0c\u672c\u8d28\u4e0a\u662f\u4e00\u4e2a\u65b0\u7684\u5bf9\u8c61\u3002\u5728\u8fd9\u4e2a\u8fc7\u7a0b\u4e2d\uff0c\u9700\u8981\u5fc5\u987b\u4fdd\u8bc1\u8001\u5e74\u4ee3\u5230\u65b0\u751f\u4ee3\u7684\u8de8\u533a\u5f15\u7528\u4ecd\u7136\u6709\u6548\u3002\u4e0b\u9762\u7684\u793a\u610f\u56fe\u8bf4\u660e\u4e86\u76f8\u5173\u8bbe\u8ba1\u3002<\/p>\n<p><img decoding=\"async\" loading=\"lazy\" width=\"776\" height=\"537\" class=\"wp-image-1401\" src=\"\/wp-content\/uploads\/2021\/03\/unnamed-file-760.png\" alt=\"\u56fe\u7247\" srcset=\"http:\/\/xinblog.ltd\/wp-content\/uploads\/2021\/03\/unnamed-file-760.png 776w, http:\/\/xinblog.ltd\/wp-content\/uploads\/2021\/03\/unnamed-file-760-300x208.png 300w, http:\/\/xinblog.ltd\/wp-content\/uploads\/2021\/03\/unnamed-file-760-768x531.png 768w\" sizes=\"(max-width: 776px) 100vw, 776px\" \/><\/p>\n<p>\u5728\u6d41\u7a0b\u57fa\u672c\u8fd8\u662f<\/p>\n<p>\u521d\u59cb\u6807\u8bb0<\/p>\n<p>\u5e76\u53d1\u6807\u8bb0<\/p>\n<p>\u6700\u7ec8\u6807\u8bb0<\/p>\n<p>\u7b5b\u9009\u56de\u6536<\/p>\n<p>\u7684\u6846\u67b6\u4e4b\u4e0a<\/p>\n<p>\u8fd8\u6709\u4e00\u4e9b\u5173\u4e8eG1\u7684\u72ec\u7279\u884c\u4e3a\u53d8\u5316<\/p>\n<p>\u5173\u4e8eHumongous,\u4f5c\u4e3a\u8001\u5e74\u4ee3\u7684\u4e00\u90e8\u5206\uff0c\u901a\u5e38\u8ba4\u4e3a\u5b83\u4f1a\u5728\u5e76\u53d1\u6807\u8bb0\u7ed3\u675f\u540e\u624d\u8fdb\u884c\u56de\u6536\uff0c\u4f46\u662f\u5728\u65b0\u7248 G1 \u4e2d\uff0cHumongous \u5bf9\u8c61\u56de\u6536\u91c7\u53d6\u4e86\u66f4\u52a0\u6fc0\u8fdb\u7684\u7b56\u7565\u3002<\/p>\n<p>Humongous \u5bf9\u8c61\u6570\u91cf\u6709\u9650\uff0c\u6240\u4ee5\u80fd\u591f\u5feb\u901f\u7684\u77e5\u9053\u662f\u5426\u6709\u8001\u5e74\u4ee3\u5bf9\u8c61\u5f15\u7528\u5b83,\u53ef\u4ee5\u7ef4\u62a4\u4e00\u4e2a\u662f\u5426\u6709\u8001\u5e74\u4ee3\u5f15\u7528\u7684\u6807\u8bc6\u4f4d,\u90a3\u4e48\u5728 Young GC \u65f6\u5c31\u53ef\u4ee5\u77e5\u9053,\u662f\u5426\u53ef\u4ee5\u56de\u6536<\/p>\n<p>\u90a3\u4e48\u603b\u7ed3\u4e00\u4e0b\u6536\u96c6\u5668<\/p>\n<p>CMS GC\u4f34\u968f\u7740\u65f6\u4ee3\u7684\u53d1\u5c55,\u5df2\u7ecf\u88ab\u5e9f\u5f03\u4e86<\/p>\n<p>\u5728GC\u7684\u53d1\u5c55\u4e2d,\u8fd8\u51fa\u73b0\u4e86\u4e00\u4e9b\u7279\u6b8a\u7684GC\u65b9\u5f0f<\/p>\n<p>Epsilson GC,\u4e0d\u8fdb\u884c\u5783\u573e\u6536\u96c6\u7684GC,\u4e13\u6ce8\u4e8e\u6027\u80fd\u6d4b\u8bd5<\/p>\n<p>ZGC,Oracle \u5f00\u6e90\u51fa\u6765\u7684\u4e00\u4e2a\u8d85\u7ea7GC\u7684\u5b9e\u73b0,\u60ca\u8bb6\u7684\u6269\u5c55\u80fd\u529b,\u652f\u6301T bytes\u7ea7\u522b\u7684\u5806\u5927\u5c0f,\u5ef6\u8fdf\u4e0d\u8d85\u8fc710ms,\u73b0\u53ea\u652f\u6301Linux 64\u4f4d\u5e73\u53f0<\/p>\n<p><img decoding=\"async\" loading=\"lazy\" width=\"1004\" height=\"672\" class=\"wp-image-1402\" src=\"\/wp-content\/uploads\/2021\/03\/unnamed-file-761.png\" alt=\"\u56fe\u7247\" srcset=\"http:\/\/xinblog.ltd\/wp-content\/uploads\/2021\/03\/unnamed-file-761.png 1004w, http:\/\/xinblog.ltd\/wp-content\/uploads\/2021\/03\/unnamed-file-761-300x201.png 300w, http:\/\/xinblog.ltd\/wp-content\/uploads\/2021\/03\/unnamed-file-761-768x514.png 768w\" sizes=\"(max-width: 1004px) 100vw, 1004px\" \/><\/p>\n<p><img decoding=\"async\" loading=\"lazy\" width=\"975\" height=\"309\" class=\"wp-image-1403\" src=\"\/wp-content\/uploads\/2021\/03\/unnamed-file-762.png\" alt=\"\u56fe\u7247\" srcset=\"http:\/\/xinblog.ltd\/wp-content\/uploads\/2021\/03\/unnamed-file-762.png 975w, http:\/\/xinblog.ltd\/wp-content\/uploads\/2021\/03\/unnamed-file-762-300x95.png 300w, http:\/\/xinblog.ltd\/wp-content\/uploads\/2021\/03\/unnamed-file-762-768x243.png 768w\" sizes=\"(max-width: 975px) 100vw, 975px\" \/><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5728JDK 6u14\u540e,\u5c31\u6709G1 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[13],"tags":[],"_links":{"self":[{"href":"http:\/\/xinblog.ltd\/index.php?rest_route=\/wp\/v2\/posts\/1398"}],"collection":[{"href":"http:\/\/xinblog.ltd\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/xinblog.ltd\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/xinblog.ltd\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/xinblog.ltd\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1398"}],"version-history":[{"count":0,"href":"http:\/\/xinblog.ltd\/index.php?rest_route=\/wp\/v2\/posts\/1398\/revisions"}],"wp:attachment":[{"href":"http:\/\/xinblog.ltd\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1398"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/xinblog.ltd\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1398"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/xinblog.ltd\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1398"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}