{"id":147,"date":"2014-12-05T16:48:37","date_gmt":"2014-12-05T08:48:37","guid":{"rendered":"http:\/\/owemeawe.com\/?p=147"},"modified":"2014-12-05T16:48:37","modified_gmt":"2014-12-05T08:48:37","slug":"%e8%b0%83%e6%95%b4%e5%86%85%e6%a0%b8printk%e7%9a%84%e6%89%93%e5%8d%b0%e7%ba%a7%e5%88%ab","status":"publish","type":"post","link":"https:\/\/peloo.net\/?p=147","title":{"rendered":"\u8c03\u6574\u5185\u6838printk\u7684\u6253\u5370\u7ea7\u522b"},"content":{"rendered":"
\u6709\u65f6\u8c03\u8bd5\u5185\u6838\u6a21\u5757\uff0c\u6253\u5370\u4fe1\u606f\u592a\u591a\u4e86\uff0c\u53ef\u4ee5\u901a\u8fc7\u4fee\u6539\/proc\/sys\/kernel\/printk\u6587\u4ef6\u5185\u5bb9\u6765\u63a7\u5236\u3002\u9ed8\u8ba4\u8bbe\u7f6e\u662f6\u00a0\u00a0\u00a04\u00a0\u00a0\u00a01\u00a0\u00a0\u00a07 <\/span># cat \/proc\/sys\/kernel\/printk<\/p>\n

7\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a04\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a01\u00a0\u00a0\u00a0\u00a0\u00a0\u00a07<\/p>\n

\u8be5\u6587\u4ef6\u6709\u56db\u4e2a\u6570\u5b57\u503c\uff0c\u5b83\u4eec\u6839\u636e\u65e5\u5fd7\u8bb0\u5f55\u6d88\u606f\u7684\u91cd\u8981\u6027\uff0c\u5b9a\u4e49\u5c06\u5176\u53d1\u9001\u5230\u4f55\u5904\u3002\u5173\u4e8e\u4e0d\u540c\u65e5\u5fd7\u7ea7\u522b\u7684\u66f4\u591a\u4fe1\u606f\uff0c\u8bf7\u67e5\u9605syslog(2)\u8054\u673a\u5e2e\u52a9\u3002\u4e0a\u9762\u663e\u793a\u76844\u4e2a\u6570\u636e\u5206\u522b\u5bf9\u5e94\uff1a<\/p>\n

\u63a7\u5236\u53f0\u65e5\u5fd7\u7ea7\u522b\uff1a\u4f18\u5148\u7ea7<\/a>\u9ad8\u4e8e\u8be5\u503c\u7684\u6d88\u606f\u5c06\u88ab\u6253\u5370\u81f3\u63a7\u5236\u53f0<\/p>\n

\u9ed8\u8ba4\u7684\u6d88\u606f\u65e5\u5fd7\u7ea7\u522b\uff1a\u5c06\u7528\u8be5\u4f18\u5148\u7ea7\u6765\u6253\u5370\u6ca1\u6709\u4f18\u5148\u7ea7\u7684\u6d88\u606f<\/p>\n

\u6700\u4f4e\u7684\u63a7\u5236\u53f0\u65e5\u5fd7\u7ea7\u522b\uff1a\u63a7\u5236\u53f0\u65e5\u5fd7\u7ea7\u522b\u53ef\u88ab\u8bbe\u7f6e\u7684\u6700\u5c0f\u503c(\u6700\u9ad8\u4f18\u5148\u7ea7)<\/p>\n

\u9ed8\u8ba4\u7684\u63a7\u5236\u53f0\u65e5\u5fd7\u7ea7\u522b\uff1a\u63a7\u5236\u53f0\u65e5\u5fd7\u7ea7\u522b\u7684\u7f3a\u7701\u503c<\/p>\n

 <\/p>\n

\u6570\u503c\u8d8a\u5c0f\uff0c\u4f18\u5148\u7ea7\u8d8a\u9ad8<\/p>\n

\u5176\u5b9e\u8fd9\u56db\u4e2a\u503c\u662f\u5728kernel\/printk.c \u4e2d\u88ab\u5b9a\u4e49\u7684\uff0c\u5982\u4e0b\uff1a<\/p>\n

int console_printk[4] = {<\/p>\n

DEFAULT_CONSOLE_LOGLEVEL,\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/* console_loglevel *\/<\/p>\n

DEFAULT_MESSAGE_LOGLEVEL,\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/* default_message_loglevel *\/<\/p>\n

MINIMUM_CONSOLE_LOGLEVEL,\u00a0\u00a0\u00a0\u00a0\u00a0\/* minimum_console_loglevel *\/<\/p>\n

DEFAULT_CONSOLE_LOGLEVEL,\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/* default_console_loglevel *\/<\/p>\n

};<\/p>\n

\u5185\u6838\u901a\u8fc7printk() \u8f93\u51fa\u7684\u4fe1\u606f\u5177\u6709\u65e5\u5fd7\u7ea7\u522b\uff0c\u65e5\u5fd7\u7ea7\u522b\u662f\u901a\u8fc7\u5728printk() \u8f93\u51fa\u7684\u5b57\u7b26\u4e32\u524d\u52a0\u4e00\u4e2a\u5e26\u5c16\u62ec\u53f7\u7684\u6574\u6570\u6765\u63a7\u5236\u7684\uff0c\u5982printk(\"<6>Hello, world!\\n\");\u3002\u5185\u6838\u4e2d\u5171\u63d0\u4f9b\u4e86\u516b\u79cd\u4e0d\u540c\u7684\u65e5\u5fd7\u7ea7\u522b\uff0c\u5728 linux\/<\/strong>kernel.h \u4e2d\u6709\u76f8\u5e94\u7684\u5b8f\u5bf9\u5e94\u3002<\/p>\n

#define KERN_EMERG\u00a0\u00a0\"<0>\"\u00a0\u00a0\u00a0\/* systemis unusable *\/<\/p>\n

#define KERN_ALERT\u00a0\u00a0\"<1>\"\u00a0\u00a0\u00a0\/* actionmust be taken immediately *\/<\/p>\n

#define KERN_CRIT\u00a0\u00a0\u00a0\u00a0\"<2>\"\u00a0\u00a0\u00a0\/*critical conditions *\/<\/p>\n

#define KERN_ERR\u00a0\u00a0\u00a0\u00a0\u00a0\"<3>\"\u00a0\u00a0\u00a0\/* errorconditions *\/<\/p>\n

#define KERN_WARNING \"<4>\"\u00a0\u00a0\u00a0\/* warning conditions *\/<\/p>\n

#define KERN_NOTICE\u00a0\u00a0\"<5>\"\u00a0\u00a0\u00a0\/* normalbut significant *\/<\/p>\n

#define KERN_INFO\u00a0\u00a0\u00a0\u00a0\"<6>\"\u00a0\u00a0\u00a0\/*informational *\/<\/p>\n

#define KERN_DEBUG\u00a0\u00a0\u00a0\"<7>\"\u00a0\u00a0\u00a0\/*debug-level messages *\/<\/p>\n

\u6240\u4ee5printk() \u53ef\u4ee5\u8fd9\u6837\u7528\uff1aprintk(KERN_INFO\"Hello, world!\\n\");\u3002<\/p>\n

\u672a\u6307\u5b9a\u65e5\u5fd7\u7ea7\u522b\u7684printk() \u91c7\u7528\u7684\u9ed8\u8ba4\u7ea7\u522b\u662fDEFAULT_MESSAGE_LOGLEVEL\uff0c\u8fd9\u4e2a\u5b8f\u5728kernel\/printk.c \u4e2d\u88ab\u5b9a\u4e49\u4e3a\u6574\u65704\uff0c\u5373\u5bf9\u5e94KERN_WARNING\u3002<\/p>\n

\u5982\u679c\u8981\u60f3\u5728\u5185\u6838\u542f\u52a8\u8fc7\u7a0b\u4e2d\u6253\u5370\u5c11\u7684\u4fe1\u606f\uff0c\u5c31\u53ef\u4ee5\u6839\u636e\u81ea\u5df1\u7684\u9700\u8981\u5728kernel\/printk.c\u4e2d\u4fee\u6539\u4ee5\u4e0a\u6570\u503c\uff0c\u91cd\u65b0\u7f16\u8bd1\u5373\u53ef\uff01<\/p>\n

\/* printk's without a loglevel use this.. *\/<\/p>\n

#define DEFAULT_MESSAGE_LOGLEVEL 4 \/* KERN_WARNING *\/<\/p>\n

 <\/p>\n

\u4e86\u89e3\u4e86\u4e0a\u9762\u7684\u8fd9\u4e9b\u77e5\u8bc6\u540e\uff0c\u6211\u4eec\u5c31\u5e94\u8be5\u77e5\u9053\u5982\u4f55\u624b\u52a8\u63a7\u5236printk\u6253\u5370\u4e86\u3002\u4f8b\u5982\uff0c\u6211\u60f3\u5c4f\u853d\u6389\u6240\u6709\u7684\u5185\u6838printk\u6253\u5370\uff0c\u90a3\u4e48\u6211\u53ea\u9700\u8981\u628a\u7b2c\u4e00\u4e2a\u6570\u503c\u8c03\u5230\u6700\u5c0f\u503c1\u6216\u80050\u3002<\/p>\n

# echo 1\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a04\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a01\u00a0\u00a0\u00a0\u00a0\u00a0\u00a07 > \/proc\/sys\/kernel\/printk<\/p>\n

\u6216\u8005<\/p>\n

# echo 0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a04\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a00\u00a0\u00a0\u00a0\u00a0\u00a0\u00a07 > \/proc\/sys\/kernel\/printk<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

\u6709\u65f6\u8c03\u8bd5\u5185\u6838\u6a21\u5757\uff0c\u6253\u5370\u4fe1\u606f\u592a\u591a\u4e86\uff0c\u53ef\u4ee5\u901a\u8fc7\u4fee\u6539\/proc\/sys\/kernel\/printk\u6587\u4ef6\u5185\u5bb9\u6765\u63a7\u5236\u3002\u9ed8\u8ba4\u8bbe\u7f6e\u662f6\u00a0\u00a0\u00a04\u00a0\u00a0\u00a01\u00a0\u00a0\u00a07 # cat \/proc\/sys\/kernel\/printk 7\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a04\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a01\u00a0\u00a0\u00a0\u00a0\u00a0\u00a07 \u8be5\u6587\u4ef6\u6709\u56db\u4e2a\u6570\u5b57\u503c\uff0c\u5b83\u4eec\u6839\u636e\u65e5\u5fd7\u8bb0\u5f55\u6d88\u606f\u7684\u91cd\u8981\u6027\uff0c\u5b9a\u4e49\u5c06\u5176\u53d1\u9001\u5230\u4f55\u5904\u3002\u5173\u4e8e\u4e0d\u540c\u65e5\u5fd7\u7ea7\u522b\u7684\u66f4\u591a\u4fe1\u606f\uff0c\u8bf7\u67e5\u9605syslog(2)\u8054\u673a\u5e2e\u52a9\u3002\u4e0a\u9762\u663e\u793a\u76844\u4e2a\u6570\u636e\u5206\u522b\u5bf9\u5e94\uff1a \u63a7\u5236\u53f0\u65e5\u5fd7\u7ea7\u522b\uff1a\u4f18\u5148\u7ea7\u9ad8\u4e8e\u8be5\u503c\u7684\u6d88\u606f\u5c06\u88ab\u6253\u5370\u81f3\u63a7\u5236\u53f0 \u9ed8\u8ba4\u7684\u6d88\u606f\u65e5\u5fd7\u7ea7\u522b\uff1a\u5c06\u7528\u8be5\u4f18\u5148\u7ea7\u6765\u6253\u5370\u6ca1\u6709\u4f18\u5148\u7ea7\u7684\u6d88\u606f \u6700\u4f4e\u7684\u63a7\u5236\u53f0\u65e5\u5fd7\u7ea7\u522b\uff1a\u63a7\u5236\u53f0\u65e5\u5fd7\u7ea7\u522b\u53ef\u88ab\u8bbe\u7f6e\u7684\u6700\u5c0f\u503c(\u6700\u9ad8\u4f18\u5148\u7ea7) \u9ed8\u8ba4\u7684\u63a7\u5236\u53f0\u65e5\u5fd7\u7ea7\u522b\uff1a\u63a7\u5236\u53f0\u65e5\u5fd7\u7ea7\u522b\u7684\u7f3a\u7701\u503c   \u6570\u503c\u8d8a\u5c0f\uff0c\u4f18\u5148\u7ea7\u8d8a\u9ad8 \u5176\u5b9e\u8fd9\u56db\u4e2a\u503c\u662f\u5728kernel\/printk.c \u4e2d\u88ab\u5b9a\u4e49\u7684\uff0c\u5982\u4e0b\uff1a int console_printk[4] = { DEFAULT_CONSOLE_LOGLEVEL,\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/* console_loglevel *\/ DEFAULT_MESSAGE_LOGLEVEL,\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/* default_message_loglevel *\/ MINIMUM_CONSOLE_LOGLEVEL,\u00a0\u00a0\u00a0\u00a0\u00a0\/* minimum_console_loglevel *\/ DEFAULT_CONSOLE_LOGLEVEL,\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/* default_console_loglevel *\/ }; \u5185\u6838\u901a\u8fc7printk() \u8f93\u51fa\u7684\u4fe1\u606f\u5177\u6709\u65e5\u5fd7\u7ea7\u522b\uff0c\u65e5\u5fd7\u7ea7\u522b\u662f\u901a\u8fc7\u5728printk() \u8f93\u51fa\u7684\u5b57\u7b26\u4e32\u524d\u52a0\u4e00\u4e2a\u5e26\u5c16\u62ec\u53f7\u7684\u6574\u6570\u6765\u63a7\u5236\u7684\uff0c\u5982printk(“<6>Hello, world!\\n”);\u3002\u5185\u6838\u4e2d\u5171\u63d0\u4f9b\u4e86\u516b\u79cd\u4e0d\u540c\u7684\u65e5\u5fd7\u7ea7\u522b\uff0c\u5728 linux\/kernel.h \u4e2d\u6709\u76f8\u5e94\u7684\u5b8f\u5bf9\u5e94\u3002 #define KERN_EMERG\u00a0\u00a0“<0>”\u00a0\u00a0\u00a0\/* systemis unusable *\/ #define KERN_ALERT\u00a0\u00a0“<1>”\u00a0\u00a0\u00a0\/* actionmust be taken immediately *\/ #define KERN_CRIT\u00a0\u00a0\u00a0\u00a0“<2>”\u00a0\u00a0\u00a0\/*critical conditions *\/ #define KERN_ERR\u00a0\u00a0\u00a0\u00a0\u00a0“<3>”\u00a0\u00a0\u00a0\/*…<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-147","post","type-post","status-publish","format-standard","hentry","category-linux"],"aioseo_notices":[],"brizy_media":[],"_links":{"self":[{"href":"https:\/\/peloo.net\/index.php?rest_route=\/wp\/v2\/posts\/147","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/peloo.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/peloo.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/peloo.net\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/peloo.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=147"}],"version-history":[{"count":1,"href":"https:\/\/peloo.net\/index.php?rest_route=\/wp\/v2\/posts\/147\/revisions"}],"predecessor-version":[{"id":148,"href":"https:\/\/peloo.net\/index.php?rest_route=\/wp\/v2\/posts\/147\/revisions\/148"}],"wp:attachment":[{"href":"https:\/\/peloo.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=147"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/peloo.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=147"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/peloo.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=147"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}