{"id":10020797,"date":"2025-05-22T04:45:39","date_gmt":"2025-05-21T20:45:39","guid":{"rendered":"https:\/\/itmax.cn\/?p=10020797"},"modified":"2025-05-22T04:45:39","modified_gmt":"2025-05-21T20:45:39","slug":"java-gc%e6%9c%ba%e5%88%b6","status":"publish","type":"post","link":"https:\/\/itmax.cn\/?p=10020797","title":{"rendered":"Java GC\u673a\u5236"},"content":{"rendered":"<h3>GC\u57fa\u672c\u539f\u7406<\/h3>\n<ol>\n<li>\u53ef\u8fbe\u6027\u5206\u6790\u7b97\u6cd5<br \/>Java\u901a\u8fc7\u6839\u53ef\u8fbe\u6027\u5206\u6790\u5224\u65ad\u5bf9\u8c61\u5b58\u6d3b\u72b6\u6001\u3002\u4eceGC Roots\uff08\u5982\u865a\u62df\u673a\u6808\u5f15\u7528\u7684\u5bf9\u8c61\u3001\u9759\u6001\u53d8\u91cf\u3001JNI    \u5f15\u7528\u7b49\uff09\u51fa\u53d1\uff0c\u904d\u5386\u5bf9\u8c61\u5f15\u7528\u94fe\uff0c\u672a\u88ab\u5f15\u7528\u7684\u5bf9\u8c61\u6807\u8bb0\u4e3a\u53ef\u56de\u6536\u3002<br \/>\u4f18\u52bf\uff1a\u89e3\u51b3\u5faa\u73af\u5f15\u7528\u95ee\u9898\uff0c\u907f\u514d\u5185\u5b58\u6cc4\u6f0f\u3002<\/li>\n<li>\n<p>\u5783\u573e\u56de\u6536\u7b97\u6cd5<\/p>\n<ul>\n<li>\u6807\u8bb0-\u6e05\u9664\uff08Mark-Sweep\uff09\uff1a\u6807\u8bb0\u5b58\u6d3b\u5bf9\u8c61\u540e\u6e05\u9664\u672a\u6807\u8bb0\u5bf9\u8c61\uff0c\u4f46\u4f1a\u4ea7\u751f\u5185\u5b58\u788e\u7247\u3002<\/li>\n<li>\u590d\u5236\u7b97\u6cd5\uff1a\u5c06\u5185\u5b58\u5206\u4e3aEden\u548cSurvivor\u533a\uff0c\u5b58\u6d3b\u5bf9\u8c61\u590d\u5236\u5230\u53e6\u4e00\u533a\u57df\uff0c\u9002\u5408\u65b0\u751f\u4ee3\uff08\u7a7a\u95f4\u5229\u7528\u738750%\uff09\u3002<\/li>\n<li>\u6807\u8bb0-\u6574\u7406\uff08Mark-Compact\uff09\uff1a\u6807\u8bb0\u540e\u538b\u7f29\u5b58\u6d3b\u5bf9\u8c61\u81f3\u5185\u5b58\u4e00\u7aef\uff0c\u6d88\u9664\u788e\u7247\uff0c\u9002\u5408\u8001\u5e74\u4ee3\u3002<\/li>\n<li>\u5206\u4ee3\u7b97\u6cd5\uff1a\u7ed3\u5408\u5bf9\u8c61\u751f\u547d\u5468\u671f\uff0c\u65b0\u751f\u4ee3\u7528\u590d\u5236\u7b97\u6cd5\uff0c\u8001\u5e74\u4ee3\u7528\u6807\u8bb0\u6574\u7406\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n<h3>\u5206\u4ee3\u56de\u6536\u673a\u5236<\/h3>\n<p>Java\u5806\u5206\u4e3a\u65b0\u751f\u4ee3\u548c\u8001\u5e74\u4ee3\uff0c\u4e0d\u540c\u533a\u57df\u91c7\u7528\u5dee\u5f02\u5316\u56de\u6536\u7b56\u7565\uff1a<\/p>\n<ol>\n<li>\n<p>\u65b0\u751f\u4ee3\u7ed3\u6784<\/p>\n<ul>\n<li>Eden\u533a\uff1a\u65b0\u5bf9\u8c61\u5206\u914d\u7684\u4e3b\u8981\u533a\u57df\uff08\u9ed8\u8ba4\u536080%\uff09\u3002<\/li>\n<li>Survivor\u533a\uff08S0\/S1\uff09\uff1aMinor GC\u540e\u5b58\u6d3b\u5bf9\u8c61\u5728\u6b64\u590d\u5236\uff0c\u5e74\u9f84\u8ba1\u6570\u5668\u51b3\u5b9a\u664b\u5347\u8001\u5e74\u4ee3\uff08\u9ed8\u8ba4\u9608\u503c15\uff09\u3002<\/li>\n<\/ul>\n<\/li>\n<li>\n<p>GC\u7c7b\u578b\u4e0e\u89e6\u53d1\u6761\u4ef6<\/p>\n<ul>\n<li>Minor GC\uff1aEden\u533a\u6ee1\u65f6\uff0c\u9ad8\u9891\u3001\u5feb\u901f\uff0c\u5b58\u6d3b\u5bf9\u8c61\u590d\u5236\u5230Survivor\u533a\u3002<\/li>\n<li>Major GC\/Full GC\uff1a\u8001\u5e74\u4ee3\u7a7a\u95f4\u4e0d\u8db3\u3001\u65b9\u6cd5\u533a\uff08\u5143\u7a7a\u95f4\uff09\u6ee1\u8f7d\u6216\u663e\u5f0f\u8c03\u7528System.gc()\u65f6\u89e6\u53d1\uff0c\u8017\u65f6\u8f83\u957f\u3002<\/li>\n<li>Mixed GC\uff08G1\u7279\u6709\uff09\uff1a\u540c\u65f6\u56de\u6536\u90e8\u5206\u65b0\u751f\u4ee3\u548c\u8001\u5e74\u4ee3Region\u3002<\/li>\n<\/ul>\n<\/li>\n<li>\n<p>\u5bf9\u8c61\u664b\u5347\u89c4\u5219<\/p>\n<ul>\n<li>\u5e74\u9f84\u9608\u503c\uff1a\u5bf9\u8c61\u5728Survivor\u533a\u6bcf\u5b58\u6d3b\u4e00\u6b21Minor GC\u5e74\u9f84+1\uff0c\u8fbe\u9608\u503c\u5219\u664b\u5347\u3002<\/li>\n<li>\u52a8\u6001\u5e74\u9f84\u5224\u65ad\uff1a\u540c\u5e74\u9f84\u5bf9\u8c61\u603b\u5927\u5c0f\u8d85Survivor\u533a\u4e00\u534a\u65f6\uff0c\u76f4\u63a5\u664b\u5347\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n<h3>GC\u89e6\u53d1\u6761\u4ef6\u4e0e\u4f18\u5316\u7b56\u7565<\/h3>\n<ol>\n<li>\n<p>\u89e6\u53d1\u6761\u4ef6\uff1a<\/p>\n<ul>\n<li>Minor GC\uff1aEden\u533a\u5206\u914d\u5931\u8d25\u3001TLAB\uff08\u7ebf\u7a0b\u672c\u5730\u5206\u914d\u7f13\u5b58\uff09\u4e0d\u8db3\u3002<\/li>\n<li>Full GC\uff1a\u8001\u5e74\u4ee3\u7a7a\u95f4\u4e0d\u8db3\u3001\u6c38\u4e45\u4ee3\uff08\u5143\u7a7a\u95f4\uff09\u6ee1\u8f7d\u3001System.gc()\u8c03\u7528\u3002<\/li>\n<\/ul>\n<\/li>\n<li>\n<p>\u8c03\u4f18\u7b56\u7565\uff1a<\/p>\n<ul>\n<li>-Xmx\/-Xms\uff1a\u8bbe\u7f6e\u6700\u5927\/\u521d\u59cb\u5927\u5c0f\uff0c\u907f\u514d\u52a8\u6001\u6269\u5c55\u5f15\u53d1Full GC\u3002<\/li>\n<li>-XX:MaxTenuringThreshold\uff1a\u8c03\u6574\u5bf9\u8c61\u664b\u5347\u5e74\u9f84\u9608\u503c\u3002<\/li>\n<li>-XX:+UseG1GC\uff1a\u542f\u7528G1\u6536\u96c6\u5668\uff0c\u5e73\u8861\u541e\u5410\u4e0e\u5ef6\u8fdf\u3002<\/li>\n<li>\u907f\u514d\u5927\u5bf9\u8c61\u76f4\u63a5\u8fdb\u5165\u8001\u5e74\u4ee3\uff08\u5982\u5927\u6570\u7ec4\uff09\u3002<\/li>\n<li>\u51cf\u5c11\u5168\u5c40\u53d8\u91cf\u548c\u9759\u6001\u96c6\u5408\u7c7b\u5f15\u7528\uff0c\u9632\u6b62\u5185\u5b58\u6cc4\u6f0f\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n<h3>\u7ecf\u5178\u5206\u4ee3\u6536\u96c6\u5668<\/h3>\n<ol>\n<li>\n<p>Serial\u6536\u96c6\u5668<\/p>\n<ul>\n<li>\u7279\u70b9\uff1a\u5355\u7ebf\u7a0b\u6267\u884c\uff0c\u5168\u7a0bSTW\uff08Stop-The-World\uff09\uff0c\u91c7\u7528\u590d\u5236\u7b97\u6cd5\uff08\u65b0\u751f\u4ee3\uff09\u548c\u6807\u8bb0-\u6574\u7406\u7b97\u6cd5\uff08\u8001\u5e74\u4ee3\uff09\u3002<\/li>\n<li>\u9002\u7528\u573a\u666f\uff1a\u5355\u6838CPU\u3001\u5c0f\u5185\u5b58\uff08\u5982\u5d4c\u5165\u5f0f\u7cfb\u7edf\uff09\u6216\u5ba2\u6237\u7aef\u5e94\u7528\u3002<\/li>\n<li>\u4ee3\u507f\u4ee3\u4ef7\uff1a\u505c\u987f\u65f6\u95f4\u957f\uff08\u79d2\u7ea7\uff09\uff0c\u65e0\u6cd5\u5229\u7528\u591a\u6838\u6027\u80fd\u3002<\/li>\n<\/ul>\n<\/li>\n<li>\n<p>ParNew\u6536\u96c6\u5668<\/p>\n<ul>\n<li>\u7279\u70b9\uff1aSerial\u7684\u591a\u7ebf\u7a0b\u7248\u672c\uff0c\u4ec5\u7528\u4f5c\u65b0\u751f\u4ee3\uff0c\u9700\u4e0eCMS\u6536\u96c6\u5668\u914d\u5408\u4f7f\u7528\u3002<\/li>\n<li>\u9002\u7528\u573a\u666f\uff1a\u591a\u6838\u670d\u52a1\u5668\u4e2d\u9700\u4e0eCMS\u642d\u914d\u7684\u573a\u666f\uff08\u5982JDK8\u524d\uff09\u3002<\/li>\n<li>\u9650\u5236\uff1aJDK9\u540e\u9010\u6e10\u88ab\u5e9f\u5f03\uff0c\u4e0eCMS\u7684\u517c\u5bb9\u6027\u8981\u6c42\u9ad8\u3002<\/li>\n<\/ul>\n<\/li>\n<li>\n<p>Parallel Scavenge\uff08\u541e\u5410\u91cf\u6536\u96c6\u5668\uff09<\/p>\n<ul>\n<li>\u7279\u70b9\uff1a\u591a\u7ebf\u7a0b\u5e76\u884c\u56de\u6536\uff0c\u4ee5\u6700\u5927\u5316\u541e\u5410\u91cf\u4e3a\u76ee\u6807\uff0c\u652f\u6301\u81ea\u9002\u5e94\u8c03\u8282\u7b56\u7565\uff08\u5982\u52a8\u6001\u8c03\u6574\u5806\u5206\u533a\u6bd4\u4f8b\uff09\u3002<\/li>\n<li>\u9002\u7528\u573a\u666f\uff1a\u540e\u53f0\u8ba1\u7b97\u578b\u4efb\u52a1\uff08\u5982\u6570\u636e\u6279\u5904\u7406\uff09\u3002<\/li>\n<li>\u4ee3\u507f\u4ee3\u4ef7\uff1a\u727a\u7272\u5355\u6b21\u505c\u987f\u65f6\u95f4\uff08\u53ef\u8fbe\u6570\u767e\u6beb\u79d2\uff09\u3002<\/li>\n<\/ul>\n<\/li>\n<li>\n<p>CMS\uff08Concurrent Mark-Sweep\uff09<\/p>\n<ul>\n<li>\u7279\u70b9\uff1a\u5e76\u53d1\u6807\u8bb0\u6e05\u9664\uff0c\u5206\u56db\u9636\u6bb5\uff08\u521d\u59cb\u6807\u8bb0-&gt;\u5e76\u53d1\u6807\u8bb0-&gt;\u91cd\u65b0\u6807\u8bb0-&gt;\u5e76\u53d1\u6e05\u9664\uff09\uff0c\u4ec5\u90e8\u5206\u9636\u6bb5STW\u3002<\/li>\n<li>\u9002\u7528\u573a\u666f\uff1a\u5ef6\u8fdf\u654f\u611f\u7684Web\u670d\u52a1\uff08\u5982\u7535\u5546\u7cfb\u7edf\uff09<\/li>\n<li>\u7f3a\u9677\uff1a\u5185\u5b58\u788e\u7247\uff08\u9700\u5b9a\u671fFull GC\u6574\u7406\uff09\u3001\u9ad8CPU\u5360\u7528\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n<h3>\u5168\u5806\u4e0e\u4f4e\u5ef6\u8fdf\u6536\u96c6\u5668<\/h3>\n<ol>\n<li>\n<p>G1\uff08Garbage-First\uff09<\/p>\n<ul>\n<li>\u7279\u70b9\uff1a\u5c06\u5806\u5212\u5206\u4e3a\u591a\u4e2aRegion\uff08\u9ed8\u8ba42048\u4e2a\uff09\uff0c\u4f18\u5148\u56de\u6536\u5783\u573e\u6bd4\u4f8b\u9ad8\u7684Region\uff0c\u652f\u6301\u53ef\u9884\u6d4b\u505c\u987f\u65f6\u95f4\u3002<\/li>\n<li>\u9002\u7528\u573a\u666f\uff1a\u5927\u5185\u5b58\uff08&gt;6GB\uff09\u670d\u52a1\u7aef\u5e94\u7528\u3002<\/li>\n<li>\u4f18\u52bf\uff1a\u5e73\u8861\u541e\u5410\u91cf\u4e0e\u5ef6\u8fdf\uff0c\u5185\u5b58\u788e\u7247\u7387\u4f4e\u4e8eCMS\u3002<\/li>\n<\/ul>\n<\/li>\n<li>\n<p>ZGC\uff08Z Garbage Collector\uff09<\/p>\n<ul>\n<li>\u7279\u70b9\uff1a\u5168\u5e76\u53d1\u64cd\u4f5c\uff08\u67d3\u8272\u6307\u9488\u6280\u672f\uff09\uff0c\u4e9a\u6beb\u79d2\u7ea7\u505c\u987f\uff08&lt;10ms\uff09\uff0c\u652f\u6301TB\u7ea7\u522b\u5185\u5b58\u3002<\/li>\n<li>\u9002\u7528\u573a\u666f\uff1a\u5b9e\u65f6\u7cfb\u7edf\uff08\u5982\u91d1\u878d\u4ea4\u6613\uff09\u3001\u8d85\u5927\u5185\u5b58\u5e94\u7528\u3002<\/li>\n<li>\u4ee3\u4ef7\uff1a\u9ad8CPU\u548c\u5185\u5b58\u5e26\u5bbd\u6d88\u8017\uff0c\u5c0f\u5806\u6027\u80fd\u53cd\u800c\u4e0d\u5982G1.<\/li>\n<\/ul>\n<\/li>\n<li>\n<p>Shenandoan<\/p>\n<ul>\n<li>\u7279\u70b9\uff1a\u7c7b\u4f3cZGC\u7684\u5168\u5e76\u53d1\u8bbe\u8ba1\uff08Brooks\u6307\u9488\uff09\uff0c\u4f4e\u505c\u987f\u4e14\u5f00\u6e90\uff0c\u4e0eZGC\u7ade\u4e89\u3002<\/li>\n<li>\u9002\u7528\u573a\u666f\uff1a\u9700\u6781\u4f4e\u5ef6\u8fdf\u4e14\u907f\u514d\u5382\u5546\u7ed1\u5b9a\uff08\u5982\u4e91\u539f\u751f\u73af\u5883\uff09\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n<h3>JVM\u8c03\u4f18<\/h3>\n<p>JVM\u8c03\u4f18\u7684\u6838\u5fc3\u76ee\u6807\u662f\u5728\u8d44\u6e90\u6d88\u8017\uff08CPU\u3001\u5185\u5b58\uff09\u3001\u541e\u5410\u91cf\u548c\u5ef6\u8fdf\u4e4b\u95f4\u627e\u5230\u5e73\u8861\u70b9\u3002<br \/>\u5173\u952e\u53c2\u6570\u6a21\u7248\uff1a<\/p>\n<pre><code class=\"bash\"># G1\u8c03\u4f18\u6a21\u677f\uff08Web\u670d\u52a1\u573a\u666f\uff09\n-Xmx8g -Xms8g \n-XX:+UseG1GC \n-XX:MaxGCPauseMillis=200 \n-XX:InitiatingHeapOccupancyPercent=45 \n-XX:ConcGCThreads=4 \n-XX:G1ReservePercent=10\n\n# ZGC\u8c03\u4f18\u6a21\u677f\uff08\u4f4e\u5ef6\u8fdf\u573a\u666f\uff09\n-Xmx16g -Xms16g \n-XX:+UseZGC \n-XX:ConcGCThreads=8 \n-XX:SoftMaxHeapSize=14g<\/code><\/pre>\n<table>\n<thead>\n<tr>\n<th>\u53c2\u6570\u7c7b\u578b<\/th>\n<th>\u793a\u4f8b\u53c2\u6570<\/th>\n<th>\u4f5c\u7528\u8bf4\u660e<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>\u5806\u5185\u5b58\u5206\u914d<\/td>\n<td>-Xmx4g -Xms4g<\/td>\n<td>\u907f\u514d\u5806\u52a8\u6001\u6269\u5bb9\u89e6\u53d1Full GC<\/td>\n<\/tr>\n<tr>\n<td>GC\u7b97\u6cd5\u9009\u62e9<\/td>\n<td>-XX:+UseG1GC<\/td>\n<td>\u6307\u5b9aG1\u6536\u96c6\u5668<\/td>\n<\/tr>\n<tr>\n<td>\u505c\u987f\u65f6\u95f4\u63a7\u5236<\/td>\n<td>-XX:MaxGCPauseMillis=200<\/td>\n<td>G1\u76ee\u6807\u6700\u5927\u505c\u987f\u65f6\u95f4<\/td>\n<\/tr>\n<tr>\n<td>\u5e76\u884cGC\u7ebf\u7a0b\u6570<\/td>\n<td>-XX:ParallelGCThreads=4<\/td>\n<td>\u6839\u636eCPU\u6838\u5fc3\u6570\u8c03\u6574<\/td>\n<\/tr>\n<tr>\n<td>\u5143\u7a7a\u95f4\u9650\u5236<\/td>\n<td>-XX:MaxMetaspaceSize=512m<\/td>\n<td>\u9632\u6b62\u5143\u7a7a\u95f4\u65e0\u9650\u589e\u957f<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><a href=\"https:\/\/segmentfault.com\/a\/1190000046551791\">https:\/\/segmentfault.com\/a\/1190000046551791<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>GC\u57fa\u672c\u539f\u7406 \u53ef\u8fbe\u6027\u5206\u6790\u7b97\u6cd5Java\u901a\u8fc7\u6839\u53ef\u8fbe\u6027\u5206\u6790\u5224\u65ad\u5bf9\u8c61\u5b58\u6d3b\u72b6\u6001\u3002\u4eceGC Roots\uff08\u5982\u865a\u62df\u673a\u6808\u5f15\u7528\u7684\u5bf9\u8c61 [&hellip;]<\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[4],"tags":[],"class_list":["post-10020797","post","type-post","status-publish","format-standard","hentry","category-share"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts\/10020797","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=10020797"}],"version-history":[{"count":0,"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts\/10020797\/revisions"}],"wp:attachment":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=10020797"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=10020797"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=10020797"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}