{"id":208372,"date":"2025-08-02T15:48:57","date_gmt":"2025-08-02T07:48:57","guid":{"rendered":"https:\/\/server.hk\/cnblog\/?p=208372"},"modified":"2025-08-02T15:48:57","modified_gmt":"2025-08-02T07:48:57","slug":"%e6%b7%b1%e5%85%a5%e8%a7%a3%e6%9e%90%e8%a8%98%e6%86%b6%e9%ab%94%e6%98%a0%e5%b0%84%e6%a9%9f%e5%88%b6%e8%88%87%e4%bc%ba%e6%9c%8d%e5%99%a8%e5%84%aa%e5%8c%96%e5%af%a6%e8%b8%90","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/208372\/","title":{"rendered":"\u6df1\u5165\u89e3\u6790\u8a18\u61b6\u9ad4\u6620\u5c04\u6a5f\u5236\u8207\u4f3a\u670d\u5668\u512a\u5316\u5be6\u8e10"},"content":{"rendered":"<h3><strong>\u4e00\u3001\u5f15\u8a00<\/strong><\/h3>\n<p class=\"ds-markdown-paragraph\">\u8a18\u61b6\u9ad4\u6620\u5c04\u662f\u4f5c\u696d\u7cfb\u7d71\u8a18\u61b6\u9ad4\u7ba1\u7406\u7684\u6838\u5fc3\u6280\u8853\uff0c\u4e0d\u50c5\u95dc\u806f\u865b\u64ec\u8a18\u61b6\u9ad4\u8207\u5be6\u9ad4\u8a18\u61b6\u9ad4\uff0c\u66f4\u80fd\u5c07\u6a94\u6848\u5167\u5bb9\u6620\u5c04\u81f3\u865b\u64ec\u8a18\u61b6\u9ad4\u7a7a\u9593\uff0c\u5be6\u73fe\u76f4\u63a5\u900f\u904e\u8a18\u61b6\u9ad4\u64cd\u4f5c\u5b58\u53d6\u6a94\u6848\u8cc7\u6599\u3002\u672c\u6559\u7a0b\u5f9e<strong>\u4f7f\u7528\u8005\u614b<\/strong>\u8207<strong>\u6838\u5fc3\u614b<\/strong>\u96d9\u91cd\u8996\u89d2\u5256\u6790\u5be6\u73fe\u539f\u7406\uff0c\u4e26\u7d50\u5408<a href=\"https:\/\/server.hk\/\">\u9999\u6e2f\u4f3a\u670d\u5668<\/a>\u7684\u4f4e\u5ef6\u9072\u7279\u6027\uff0c\u63a2\u8a0e\u5176\u5728\u9ad8\u6548\u80fd\u5834\u666f\u4e0b\u7684\u512a\u5316\u61c9\u7528\u3002\u5168\u6587\u7d50\u69cb\u5206\u70ba\u56db\u90e8\u5206\uff1a<\/p>\n<ol start=\"1\">\n<li>\n<p class=\"ds-markdown-paragraph\">\u4f7f\u7528\u8005\u614b\u8a18\u61b6\u9ad4\u6620\u5c04<\/p>\n<\/li>\n<li>\n<p class=\"ds-markdown-paragraph\">\u6838\u5fc3\u614b\u8a18\u61b6\u9ad4\u6620\u5c04<\/p>\n<\/li>\n<li>\n<p class=\"ds-markdown-paragraph\">\u7f3a\u9801\u7570\u5e38\u8655\u7406<\/p>\n<\/li>\n<li>\n<p class=\"ds-markdown-paragraph\">\u4f3a\u670d\u5668\u512a\u5316\u5efa\u8b70<br \/>\n\u78ba\u4fdd\u5167\u5bb9\u5c64\u6b21\u6e05\u6670\u4e14\u6613\u65bc\u7406\u89e3\u3002<\/p>\n<\/li>\n<\/ol>\n<hr \/>\n<h3><strong>\u4e8c\u3001\u4f7f\u7528\u8005\u614b\u8a18\u61b6\u9ad4\u6620\u5c04<\/strong><\/h3>\n<p class=\"ds-markdown-paragraph\">\u4f7f\u7528\u8005\u614b\u7684\u8a18\u61b6\u9ad4\u5206\u914d\u901a\u5e38\u900f\u904e\u00a0<code>malloc()<\/code>\u00a0\u5be6\u73fe\uff0c\u5e95\u5c64\u4f9d\u8cf4\u8a18\u61b6\u9ad4\u6620\u5c04\u6a5f\u5236\u3002\u6839\u64da\u5206\u914d\u5927\u5c0f\uff0c\u7cfb\u7d71\u9078\u64c7\u00a0<code>brk()<\/code>\u00a0\u6216\u00a0<code>mmap()<\/code>\u00a0\u7cfb\u7d71\u547c\u53eb\uff1a<\/p>\n<h4><strong>2.1 \u5c0f\u584a\u8a18\u61b6\u9ad4\u5206\u914d\uff08brk\uff09<\/strong><\/h4>\n<p class=\"ds-markdown-paragraph\">\u9069\u7528\u65bc\u00a0<strong>&lt;128KB<\/strong>\u00a0\u7684\u5206\u914d\uff0cC\u6a19\u6e96\u5eab\u900f\u904e\u8abf\u6574\u5806\u9802\u6307\u6a19\u5b8c\u6210\uff1a<\/p>\n<div class=\"md-code-block md-code-block-light\">\n<div class=\"md-code-block-banner-wrap\">\n<div class=\"md-code-block-banner md-code-block-banner-lite\">\n<div class=\"_121d384\">\n<div class=\"d2a24f03\"><span class=\"d813de27\">plaintext<\/span><\/div>\n<div class=\"d2a24f03\">\n<div class=\"efa13877\"><\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<pre>\u250c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2510\r\n\u2502 \u5806\u9802\u8abf\u6574\uff1asys_brk() \u6bd4\u5c0d\u65b0\u820a\u5806\u9802\u4f4d\u5740        \u2502\r\n\u2502 \u9801\u9762\u5c0d\u9f4a\uff1a\u5224\u65b7\u662f\u5426\u4f4d\u65bc\u540c\u4e00\u9801\u9762              \u2502\r\n\u251c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2524\r\n\u2502 \u540c\u4e00\u9801\u9762 \u2192 \u66f4\u65b0 mm-&gt;brk                 \u2502\r\n\u2502 \u65b0\u5806\u9802 &lt; \u820a\u5806\u9802 \u2192 __do_munmap() \u91cb\u653e\u8a18\u61b6\u9ad4 \u2502\r\n\u2502 \u65b0\u5206\u914d \u2192 find_vma() + do_brk_flags()   \u2502\r\n\u2514\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2518<\/pre>\n<\/div>\n<ul>\n<li>\n<p class=\"ds-markdown-paragraph\">\u2714\ufe0f\u00a0<strong>\u512a\u52e2<\/strong>\uff1a\u8a18\u61b6\u9ad4\u5feb\u53d6\u6a5f\u5236\u964d\u4f4e\u7f3a\u9801\u7570\u5e38\u983b\u7387<\/p>\n<\/li>\n<li>\n<p class=\"ds-markdown-paragraph\">\u26a0\ufe0f\u00a0<strong>\u52a3\u52e2<\/strong>\uff1a\u5feb\u53d6\u53ef\u80fd\u5c0e\u81f4\u8a18\u61b6\u9ad4\u788e\u7247<\/p>\n<\/li>\n<\/ul>\n<h4><strong>2.2 \u5927\u584a\u8a18\u61b6\u9ad4\u5206\u914d\uff08mmap\uff09<\/strong><\/h4>\n<p class=\"ds-markdown-paragraph\">\u9069\u7528\u65bc\u00a0<strong>&gt;128KB<\/strong>\u00a0\u7684\u5206\u914d\uff1a<\/p>\n<div class=\"md-code-block md-code-block-light\">\n<div class=\"md-code-block-banner-wrap\">\n<div class=\"md-code-block-banner md-code-block-banner-lite\">\n<div class=\"_121d384\">\n<div class=\"d2a24f03\"><span class=\"d813de27\">plaintext<\/span><\/div>\n<div class=\"d2a24f03\">\n<div class=\"efa13877\"><\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<pre>\u250c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2510\r\n\u2502 1. \u547c\u53eb get_unmapped_area() \u67e5\u627e\u53ef\u7528\u5340\u57df \u2502\r\n\u2502 2. mmap_region() \u5efa\u7acbVMA\u4e26\u52a0\u5165\u7d05\u9ed1\u6a39     \u2502\r\n\u2502 3. \u6a94\u6848\u6620\u5c04 \u2192 \u66f4\u65b0 address_space \u7d50\u69cb    \u2502\r\n\u2514\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2518<\/pre>\n<\/div>\n<ul>\n<li>\n<p class=\"ds-markdown-paragraph\">\u2714\ufe0f\u00a0<strong>\u512a\u52e2<\/strong>\uff1a\u91cb\u653e\u8a18\u61b6\u9ad4\u76f4\u63a5\u6b78\u9084\u7cfb\u7d71\uff0c\u907f\u514d\u788e\u7247<\/p>\n<\/li>\n<li>\n<p class=\"ds-markdown-paragraph\">\u26a0\ufe0f\u00a0<strong>\u52a3\u52e2<\/strong>\uff1a\u6bcf\u6b21\u6620\u5c04\u53ef\u80fd\u89f8\u767c\u7f3a\u9801\u7570\u5e38<\/p>\n<\/li>\n<\/ul>\n<hr \/>\n<h3><strong>\u4e09\u3001\u6838\u5fc3\u614b\u8a18\u61b6\u9ad4\u6620\u5c04<\/strong><\/h3>\n<p class=\"ds-markdown-paragraph\">\u6838\u5fc3\u614b\u6620\u5c04\u6ce8\u91cd\u9ad8\u6548\u6027\u8207\u9748\u6d3b\u6027\uff0c\u95dc\u9375\u51fd\u6578\u5305\u62ec\uff1a<\/p>\n<div class=\"markdown-table-wrapper\">\n<table>\n<thead>\n<tr>\n<th>\u51fd\u6578<\/th>\n<th>\u61c9\u7528\u5834\u666f<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><code>vmalloc()<\/code><\/td>\n<td>\u5206\u914d\u865b\u64ec\u9023\u7e8c\u4f46\u5be6\u9ad4\u4e0d\u9023\u7e8c\u7684\u9801\u9762<\/td>\n<\/tr>\n<tr>\n<td><code>kmalloc()<\/code><\/td>\n<td>\u7d50\u5408\u5925\u4f34\u7cfb\u7d71\u8207SLUB\u5206\u914d\u5668\uff08\u5167\u6838\u512a\u5316\uff09<\/td>\n<\/tr>\n<tr>\n<td><code>kmem_cache_alloc()<\/code><\/td>\n<td>\u7cbe\u6e96\u5206\u914d\u5c0f\u584a\u8a18\u61b6\u9ad4<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<h4><strong>3.1 \u81e8\u6642\u6620\u5c04\uff08kmap_atomic\uff09<\/strong><\/h4>\n<div class=\"md-code-block md-code-block-light\">\n<div class=\"md-code-block-banner-wrap\">\n<div class=\"md-code-block-banner md-code-block-banner-lite\">\n<div class=\"_121d384\">\n<div class=\"d2a24f03\"><span class=\"d813de27\">plaintext<\/span><\/div>\n<div class=\"d2a24f03\">\n<div class=\"efa13877\"><\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<pre>\u4f4e\u7aef\u8a18\u61b6\u9ad4 \u2192 \u900f\u904e __va \u76f4\u63a5\u6620\u5c04  \r\n\u9ad8\u7aef\u8a18\u61b6\u9ad4 \u2192 set_pte \u5efa\u7acb\u6838\u5fc3\u9801\u8868\u81e8\u6642\u6620\u5c04<\/pre>\n<\/div>\n<blockquote>\n<p class=\"ds-markdown-paragraph\">\ud83d\udccc\u00a0<strong>\u61c9\u7528\u5834\u666f<\/strong>\uff1a\u4f3a\u670d\u5668\u9ad8\u6548\u80fd\u904b\u7b97\u4e2d\u5feb\u901f\u97ff\u61c9\u52d5\u614b\u8a18\u61b6\u9ad4\u9700\u6c42<\/p>\n<\/blockquote>\n<hr \/>\n<h3><strong>\u56db\u3001\u7f3a\u9801\u7570\u5e38\u8655\u7406<\/strong><\/h3>\n<p class=\"ds-markdown-paragraph\">\u8a2a\u554f\u672a\u6620\u5c04\u7684\u865b\u64ec\u4f4d\u5740\u89f8\u767c\u00a0<code>do_page_fault()<\/code>\uff1a<\/p>\n<div class=\"md-code-block md-code-block-light\">\n<div class=\"md-code-block-banner-wrap\">\n<div class=\"md-code-block-banner md-code-block-banner-lite\">\n<div class=\"_121d384\">\n<div class=\"d2a24f03\">\n<div class=\"ds-segmented _81e8954\" role=\"tablist\">\n<div class=\"ds-segmented-button ds-segmented-button--selected\" role=\"tab\" aria-selected=\"true\">\n<pre><span class=\"token keyword\">graph<\/span> LR\r\nA<span class=\"token text string\">[\u7f3a\u9801\u7570\u5e38]<\/span> <span class=\"token arrow operator\">--&gt;<\/span> B<span class=\"token text string\">{\u6838\u5fc3\u614b\uff1f}<\/span>\r\nB <span class=\"token arrow operator\">--&gt;<\/span><span class=\"token label property\">|\u662f|<\/span> C<span class=\"token text string\">[\u547c\u53eb vmalloc_fault \u540c\u6b65\u9801\u8868]<\/span>\r\nB <span class=\"token arrow operator\">--&gt;<\/span><span class=\"token label property\">|\u5426|<\/span> D<span class=\"token text string\">[find_vma \u5b9a\u4f4dVMA]<\/span>\r\nD <span class=\"token arrow operator\">--&gt;<\/span> E<span class=\"token text string\">[handle_mm_fault \u5efa\u7acb\u6620\u5c04]<\/span>\r\nE <span class=\"token arrow operator\">--&gt;<\/span> F<span class=\"token text string\">{\u6620\u5c04\u985e\u578b}<\/span>\r\nF <span class=\"token arrow operator\">--&gt;<\/span><span class=\"token label property\">|\u533f\u540d\u9801|<\/span> G<span class=\"token text string\">[do_anonymous_page \u5206\u914d\u9801\u9762]<\/span>\r\nF <span class=\"token arrow operator\">--&gt;<\/span><span class=\"token label property\">|\u6a94\u6848\u6620\u5c04|<\/span> H<span class=\"token text string\">[filemap_fault \u52a0\u8f09\u8cc7\u6599]<\/span>\r\nF <span class=\"token arrow operator\">--&gt;<\/span><span class=\"token label property\">|\u4ea4\u63db\u9801|<\/span> I<span class=\"token text string\">[do_swap_page \u8b80\u53d6\u4ea4\u63db\u5340]<\/span><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<blockquote>\n<p class=\"ds-markdown-paragraph\">\ud83d\udd27 <strong>\u512a\u5316\u5efa\u8b70<\/strong>\uff1a\u555f\u7528TLB\uff08\u5feb\u8868\uff09\u52a0\u901f\u4f4d\u5740\u8f49\u63db<\/p>\n<\/blockquote>\n<hr \/>\n<h3><strong>\u4e94\u3001\u4f3a\u670d\u5668\u8a18\u61b6\u9ad4\u6620\u5c04\u512a\u5316<\/strong><\/h3>\n<p class=\"ds-markdown-paragraph\">\u91dd\u5c0d\u4f4e\u5ef6\u9072\/\u9ad8\u983b\u5bec\u5834\u666f\u7684\u95dc\u9375\u7b56\u7565\uff1a<\/p>\n<div class=\"markdown-table-wrapper\">\n<table>\n<thead>\n<tr>\n<th>\u512a\u5316\u65b9\u5411<\/th>\n<th>\u5177\u9ad4\u63aa\u65bd<\/th>\n<th>\u6548\u76ca<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><strong>\u6e1b\u5c11\u8a18\u61b6\u9ad4\u788e\u7247<\/strong><\/td>\n<td>\u512a\u5148\u4f7f\u7528\u00a0<code>mmap()<\/code>\u00a0\u5206\u914d\u5927\u584a\u8a18\u61b6\u9ad4<\/td>\n<td>\u907f\u514d brk() \u788e\u7247\u554f\u984c<\/td>\n<\/tr>\n<tr>\n<td><strong>TLB \u512a\u5316<\/strong><\/td>\n<td>\u8abf\u6574\u9801\u9762\u5927\u5c0f\u63d0\u5347\u547d\u4e2d\u7387<\/td>\n<td>\u26a1 \u8a18\u61b6\u9ad4\u5b58\u53d6\u52a0\u901f 30%+<\/td>\n<\/tr>\n<tr>\n<td><strong>\u5feb\u53d6\u7ba1\u7406<\/strong><\/td>\n<td>\u512a\u5316 kmalloc\/kmem_cache_alloc<\/td>\n<td>\u63d0\u5347\u6838\u5fc3\u614b\u6548\u7387<\/td>\n<\/tr>\n<tr>\n<td><strong>\u8ca0\u8f09\u5e73\u8861<\/strong><\/td>\n<td>\u5408\u7406\u914d\u7f6e\u9801\u9762\u5feb\u53d6<\/td>\n<td>\u964d\u4f4e\u7f3a\u9801\u7570\u5e38\u983b\u7387<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<hr \/>\n<h3><strong>\u516d\u3001\u7e3d\u7d50<\/strong><\/h3>\n<p class=\"ds-markdown-paragraph\">\u8a18\u61b6\u9ad4\u6620\u5c04\u4f5c\u70ba\u865b\u64ec\/\u5be6\u9ad4\u8a18\u61b6\u9ad4\u7684\u6a4b\u6a11\uff0c\u6db5\u84cb\uff1a<\/p>\n<ul>\n<li>\n<p class=\"ds-markdown-paragraph\"><strong>\u4f7f\u7528\u8005\u614b<\/strong>\uff1a<code>brk()<\/code>\u00a0\/\u00a0<code>mmap()<\/code>\u00a0\u96d9\u6a5f\u5236<\/p>\n<\/li>\n<li>\n<p class=\"ds-markdown-paragraph\"><strong>\u6838\u5fc3\u614b<\/strong>\uff1a<code>vmalloc()<\/code>\u00a0\/\u00a0<code>kmap_atomic()<\/code>\u00a0\u591a\u5c64\u7b56\u7565<\/p>\n<\/li>\n<li>\n<p class=\"ds-markdown-paragraph\"><strong>\u7570\u5e38\u8655\u7406<\/strong>\uff1a\u52d5\u614b\u5206\u914d\u9801\u9762\u4fdd\u969c\u8cc7\u6599\u5b58\u53d6<\/p>\n<\/li>\n<\/ul>\n<p class=\"ds-markdown-paragraph\">\u5728<a href=\"https:\/\/server.hk\/\">\u9999\u6e2f\u4f3a\u670d\u5668<\/a>\u7684\u5be6\u8e10\u4e2d\uff0c\u900f\u904e\uff1a<br \/>\n\u2705 \u5408\u7406\u9078\u64c7\u6620\u5c04\u65b9\u5f0f<br \/>\n\u2705 \u5229\u7528 TLB \u8207\u5feb\u53d6\u6a5f\u5236<br \/>\n\u2705 \u7d50\u5408\u4f4e\u5ef6\u9072\u786c\u9ad4\u7279\u6027<br \/>\n\u53ef\u986f\u8457\u63d0\u5347\u7cfb\u7d71\u6548\u80fd\uff0c\u70ba\u958b\u767c\u8005\u63d0\u4f9b\u9ad8\u6548\u6280\u8853\u65b9\u6848\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e00\u3001\u5f15\u8a00 \u8a18\u61b6\u9ad4\u6620\u5c04\u662f\u4f5c\u696d\u7cfb\u7d71\u8a18&#46;&#46;&#46;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4924],"tags":[],"class_list":["post-208372","post","type-post","status-publish","format-standard","hentry","category-setup-tutorials"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/208372","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=208372"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/208372\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=208372"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=208372"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=208372"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}