{"id":22466,"date":"2025-11-06T02:30:23","date_gmt":"2025-11-06T02:30:23","guid":{"rendered":"https:\/\/pokecon.jp\/job\/?p=22466"},"modified":"2025-11-06T02:30:23","modified_gmt":"2025-11-06T02:30:23","slug":"linux%e3%82%ab%e3%83%bc%e3%83%8d%e3%83%ab%e8%a7%a3%e8%aa%ad%e5%ae%a4%e3%83%97%e3%83%ad%e3%82%b8%e3%82%a7%e3%82%af%e3%83%88-%e6%96%b0linux%e3%82%ab%e3%83%bc%e3%83%8d%e3%83%ab%e8%a7%a3%e8%aa%ad","status":"publish","type":"post","link":"https:\/\/pokecon.jp\/job\/22466\/","title":{"rendered":"Linux\u30ab\u30fc\u30cd\u30eb\u89e3\u8aad\u5ba4\u30d7\u30ed\u30b8\u30a7\u30af\u30c8: \u65b0Linux\u30ab\u30fc\u30cd\u30eb\u89e3\u8aad\u5ba4 – Workqueue – VA Linux \u30a8\u30f3\u30b8\u30cb\u30a2\u30d6\u30ed\u30b0"},"content":{"rendered":"\n<\/p>\n
\n

\u300cLinux\u30ab\u30fc\u30cd\u30eb2.6\u89e3\u8aad\u5ba4\u300d\uff08\u4ee5\u964d\u3001\u65e7\u30ab\u30fc\u30cd\u30eb\u89e3\u8aad\u5ba4\uff09\u51fa\u7248\u5f8c\u3001Linux\u306b\u306f\u591a\u304f\u306e\u6a5f\u80fd\u304c\u8ffd\u52a0\u3055\u308c\u3001\u30a8\u30f3\u30bf\u30fc\u30d7\u30e9\u30a4\u30ba\u9818\u57df\u3092\u306f\u3058\u3081\u3068\u3059\u308b\u69d8\u3005\u306a\u5834\u6240\u3067\u4f7f\u308f\u308c\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3057\u305f\u3002
\u305d\u308c\u306b\u4f34\u3044\u30b3\u30fc\u30c9\u304c\u80a5\u5927\u304b\u3064\u8907\u96d1\u5316\u3057\u3001\u591a\u304f\u306e\u30a8\u30f3\u30b8\u30cb\u30a2\u306b\u3068\u3063\u3066\u89e3\u8aad\u4e0d\u80fd\u306a\u30d6\u30e9\u30c3\u30af\u30dc\u30c3\u30af\u30b9\u3068\u306a\u3063\u3066\u3044\u307e\u3059\u3002
\u4e16\u754c\u4e2d\u306e\u30c8\u30c3\u30d7\u30a8\u30f3\u30b8\u30cb\u30a2\u9054\u306e\u5091\u4f5c\u3067\u3042\u308bLinux\u30ab\u30fc\u30cd\u30eb\u306b\u30e1\u30b9\u3092\u5165\u308c\u3001\u30d6\u30e9\u30c3\u30af\u30dc\u30c3\u30af\u30b9\u3092\u3053\u3058\u958b\u3051\u3066\u3001\u6642\u306b\u597d\u5947\u5fc3\u306e\u8d74\u304f\u307e\u307e\u306b\u30ab\u30fc\u30cd\u30eb\u306e\u4e16\u754c\u3092\u89e3\u8aad\u3059\u308b\u300c\u65b0Linux\u30ab\u30fc\u30cd\u30eb\u89e3\u8aad\u5ba4\u300d\u30d7\u30ed\u30b8\u30a7\u30af\u30c8\u3002<\/p>\n

\u57f7\u7b46\u8005 : Ryo Takakura<\/p>\n

\u203b \u300c\u65b0Linux\u30ab\u30fc\u30cd\u30eb\u89e3\u8aad\u5ba4\u300d\u9023\u8f09\u8a18\u4e8b\u4e00\u89a7\u306f\u3053\u3061\u3089<\/a><\/p>\n\n

\u9045\u5ef6\u51e6\u7406\u306e\u4ed5\u7d44\u307f\u3067\u3042\u308bWorkqueue (WQ) \u306b\u3064\u3044\u3066\u7d39\u4ecb\u3057\u305f\u3044\u3068\u601d\u3044\u307e\u3059\u3002WQ\u306f\u65e7\u30ab\u30fc\u30cd\u30eb\u89e3\u8aad\u5ba4\u3067\u3082\u89e3\u8aac\u3055\u308c\u3066\u3044\u307e\u3059\u304c\u3001\u305d\u306e\u5b9f\u88c5\u306f\u5f53\u6642 (v2.6) \u304b\u3089\u5927\u304d\u304f\u5909\u308f\u3063\u3066\u3044\u307e\u3059\u3002\u672c\u8a18\u4e8b\u3067\u306f\u3001\u5f53\u6642\u306eWQ (\u4ee5\u5f8c\u65e7WQ) \u304c\u73fe\u5728\u306e\u5b9f\u88c5\u306b\u81f3\u308b\u307e\u3067\u3092\u3001\u80cc\u666f\u7b49\u3092\u4ea4\u3048\u306a\u304c\u3089\u7d39\u4ecb\u3067\u304d\u308c\u3070\u3068\u601d\u3044\u307e\u3059\u3002\u306a\u304a\u672c\u8a18\u4e8b\u306f\u3001\u7b46\u8005\u304cWQ\u3092\u8abf\u3079\u3066\u3044\u3066\u9762\u767d\u3044\u3068\u611f\u3058\u305f\u3053\u3068\u3092\u307e\u3068\u3081\u305f\u3088\u3046\u306a\u8a18\u4e8b\u3067\u3059\u3002\u8aad\u8005\u306e\u65b9\u304c\u672c\u8a18\u4e8b\u3092\u901a\u3057\u3066WQ\u306b\u8208\u5473\u3092\u6301\u3063\u3066\u9802\u3051\u305f\u3089\u5b09\u3057\u3044\u3067\u3059\u3002<\/p>\n

WQ\u306f\u3001Linux\u306b\u304a\u3044\u3066\u7528\u610f\u3055\u308c\u3066\u3044\u308b\u9045\u5ef6\u51e6\u7406\u306e\u4ed5\u7d44\u307f\u306e\u4e00\u3064\u3067\u3059\u3002\u9045\u5ef6\u51e6\u7406\u3092\u884c\u3046\u76ee\u7684\u306f\u3001\u30bd\u30d5\u30c8\u5272\u308a\u8fbc\u307f\u306e\u3088\u3046\u306a\u30cf\u30fc\u30c9\u5272\u308a\u8fbc\u307f\u306e\u51e6\u7406\u3092\u9045\u5ef6\u3055\u305b\u30ab\u30fc\u30cd\u30eb\u306e\u5fdc\u7b54\u6027\u3092\u5411\u4e0a\u3055\u305b\u308b\u305f\u3081\u3067\u3042\u3063\u305f\u308a\u3001NMI\u306e\u3088\u3046\u306b\u30b3\u30f3\u30c6\u30ad\u30b9\u30c8\u81ea\u4f53\u306b\u5236\u7d04 (\u30ed\u30c3\u30af\u53d6\u5f97\u306a\u3069) \u304c\u3042\u308a\u4ed6\u30b3\u30f3\u30c6\u30ad\u30b9\u30c8\u306b\u51e6\u7406\u3092\u59d4\u8b72\u3059\u308b\u5fc5\u8981\u304c\u3042\u3063\u305f\u308a\u3068\u69d8\u3005\u3067\u3059\u3002WQ\u306f\u3001\u51e6\u7406\u3092\u30d7\u30ed\u30bb\u30b9\u30b3\u30f3\u30c6\u30ad\u30b9\u30c8\u3078\u9045\u5ef6\u3059\u308b\u305f\u3081\u306b\u63d0\u4f9b\u3055\u308c\u3066\u3044\u308b\u4ed5\u7d44\u307f\u3067\u3059\u3002\u5404\u7a2e\u30c7\u30d0\u30a4\u30b9\u30c9\u30e9\u30a4\u30d0\u3084\u30d5\u30a1\u30a4\u30eb\u30b7\u30b9\u30c6\u30e0\u306eIO\u306a\u3069\u30ab\u30fc\u30cd\u30eb\u3067\u5e45\u5e83\u304f\u4f7f\u308f\u308c\u3066\u3044\u307e\u3059\u3002\u51e6\u7406\u3092\u5b9f\u884c\u3059\u308b\u30b9\u30ec\u30c3\u30c9\u306f\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u3001\u5b9f\u884c\u3055\u308c\u308b\u51e6\u7406\u306f\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u3068\u547c\u3070\u308c\u307e\u3059\u3002\u672c\u8a18\u4e8b\u3067\u306f\u3001\u3053\u306e\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u304c\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u3092\u5b9f\u884c\u3059\u308b\u307e\u3067\u306e\u4ed5\u7d44\u307f\u3092\u3001\u307e\u305a\u306f\u6bd4\u8f03\u7684\u30b7\u30f3\u30d7\u30eb\u306b\u5b9f\u88c5\u3055\u308c\u3066\u3044\u305f\u65e7WQ\u306b\u304a\u3044\u3066\u78ba\u8a8d\u3057\u305f\u3044\u3068\u601d\u3044\u307e\u3059\u3002\u305d\u306e\u5f8c\u3001\u73fe\u5728\u306eWQ\u306e\u30d9\u30fc\u30b9\u3068\u306a\u308bConcurrency Managed Workqueue (CMWQ) \u304c\u53d6\u308a\u8fbc\u307e\u308c\u305f\u76f4\u5f8c\u306e\u5b9f\u88c5\u3092\u53c2\u7167\u3057\u306a\u304c\u3089\u3001WQ\u306b\u304a\u3051\u308b “Concurrency Management” \u306b\u3064\u3044\u3066\u304a\u3055\u3089\u3044\u3057\u305f\u306e\u3061\u3001\u65e7WQ\u3068\u6bd4\u8f03\u3059\u308b\u5f62\u3067\u305d\u306e\u5fc5\u8981\u6027\u3092\u78ba\u8a8d\u3057\u3066\u3044\u304d\u307e\u3059\u3002\u73fe\u5728\u306eWQ\u306e\u5b9f\u88c5\u3068\u76f4\u8fd1\u306eWQ\u306b\u304a\u3051\u308b\u53d6\u308a\u7d44\u307f\u306b\u3064\u3044\u3066\u3082\u3001\u6700\u5f8c\u306b\u7c21\u5358\u306b\u7d39\u4ecb\u3067\u304d\u308c\u3070\u3068\u601d\u3044\u307e\u3059\u3002\u306a\u304a\u8a18\u4e8b\u3067\u306f\u3001alloc_workqueue()<\/a>, destroy_workqueue()<\/a> \u7b49\u3067\u64cd\u4f5c\u306e\u5bfe\u8c61\u3068\u306a\u308b “workqueue” \u306f\u3001\u30b7\u30b9\u30c6\u30e0\u3068\u3057\u3066\u306e”WQ”\u3068\u533a\u5225\u3057\u3066\u4f7f\u7528\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n

WQ\u3067\u306f\u3001v2.6.36\u306b\u304a\u3044\u3066\u53d6\u308a\u8fbc\u307e\u308c\u305fCMWQ\u4ee5\u524d\u306e\u5b9f\u88c5\u3092Legacy Workqueue (\u65e7WQ)\u3001\u4ee5\u964d\u306e\u5b9f\u88c5\u3092Concurrency Managed Workqueue (CMWQ) \u3068\u3057\u3066\u533a\u5225\u3057\u3066\u3044\u307e\u3059\u3002\u672c\u7ae0\u3067\u306f\u3001\u65e7WQ\u306e\u5b9f\u88c5\u304a\u3088\u3073\u5f53\u6642\u6319\u3052\u3089\u308c\u3066\u3044\u305f\u65e7WQ\u306e\u8ab2\u984c\u3092\u78ba\u8a8d\u3057\u305f\u3044\u3068\u601d\u3044\u307e\u3059\u3002\u306a\u304a\u3001\u672c\u7ae0\u304c\u89e3\u8aac\u306e\u30d9\u30fc\u30b9\u3068\u3059\u308b\u30d0\u30fc\u30b8\u30e7\u30f3\u306fv2.6.35\u3067\u3059\u3002<\/p>\n

workqueue_struct\u69cb\u9020\u4f53<\/h2>\n

workqueue_struct\u69cb\u9020\u4f53\u306f\u3001\u65e7WQ\u304b\u3089\u73fe\u5728\u306b\u81f3\u308b\u307e\u3067\u3001\u5404workqueue\u306b\u5272\u308a\u5f53\u3066\u3089\u308c\u308b\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u3068\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u3092\u7ba1\u7406\u3059\u308b\u5f79\u5272\u3092\u62c5\u3063\u3066\u304d\u305f\u69cb\u9020\u4f53\u3067\u3059\u3002\u3053\u3053\u3067\u306f\u3001\u65e7\u30ab\u30fc\u30cd\u30eb\u89e3\u8aad\u5ba4 (\u65e7WQ) \u306eworkqueue_struct<\/a>\u69cb\u9020\u4f53\u306e\u8aac\u660e\u3092\u305d\u306e\u307e\u307e\u53c2\u7167\u3057\u3066\u307f\u305f\u3044\u3068\u601d\u3044\u307e\u3059\u3002workqueue_struct\u69cb\u9020\u4f53\u306e\u8003\u3048\u65b9\u306f\u3001\u65e7\u30ab\u30fc\u30cd\u30eb\u89e3\u8aad\u5ba4\u5f53\u6642\u304b\u3089\u57fa\u672c\u7684\u306b\u5909\u308f\u3063\u3066\u3044\u307e\u305b\u3093\u304c\u3001\u65e7WQ\u3068CMWQ\u306b\u304a\u3051\u308b\u5927\u304d\u306a\u9055\u3044\u3068\u3057\u3066\u5272\u308a\u5f53\u3066\u3089\u308c\u308b\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u304c\u6319\u3052\u3089\u308c\u307e\u3059\u3002\u305d\u306e\u305f\u3081\u3001\u672c\u8a18\u4e8b\u306e\u30c6\u30fc\u30de\u306f\u3001(\u3056\u3063\u304f\u308a\u3068) workqueue\u306b\u5bfe\u3059\u308b\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u306e\u5272\u308a\u5f53\u3066\u65b9\u306e\u5909\u9077\u3067\u3059\u3002<\/p>\n

\n

workqueue\u306f\u3001workqueue_struct\u69cb\u9020\u4f53\u306e\u914d\u5217\u3067\u3001\u76ee\u7684\u3054\u3068\u306b\u5c02\u7528\u306eworkqueue\u3092\u7528\u610f\u3057\u3066\u3044\u307e\u3059\u3002\u305d\u308c\u305e\u308c\u306eCPU\u7528\u306e\u30a8\u30f3\u30c8\u30ea\u3092\u6301\u3061\u3001\u305d\u306eCPU\u4e0a\u3067\u5b9f\u884c\u3059\u3079\u304d\u51e6\u7406 (work_struct\u69cb\u9020\u4f53) \u3092\u8907\u6570\u767b\u9332\u3067\u304d\u307e\u3059\u3002
\u5404workqueue_struct\u69cb\u9020\u4f53\u306b\u306f\u3001\u5c02\u7528\u306e\u30ab\u30fc\u30cd\u30eb\u30b9\u30ec\u30c3\u30c9\u304c\u5272\u308a\u5f53\u3066\u3089\u308c\u3066\u3044\u307e\u3059\u3002\u304a\u306e\u304a\u306e\u306e\u30b9\u30ec\u30c3\u30c9\u306f\u3001\u5c5e\u3057\u3066\u3044\u308bworkqueue_struct\u69cb\u9020\u4f53\u306b\u767b\u9332\u3055\u308c\u3066\u3044\u308b\u51e6\u7406\u3092 (work_struct\u69cb\u9020\u4f53) \u3092\u5b9f\u884c\u3059\u308b\u5f79\u76ee\u3092\u53d7\u3051\u6301\u3061\u307e\u3059\u3002\u30de\u30eb\u30c1\u30d7\u30ed\u30bb\u30c3\u30b5\u30b7\u30b9\u30c6\u30e0\u306e\u5834\u5408\u3001\u305d\u308c\u305e\u308c\u306eCPU\u7528\u306b\u5c02\u7528\u306e\u30ab\u30fc\u30cd\u30eb\u30b9\u30ec\u30c3\u30c9\u3092\u7528\u610f\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n<\/blockquote>\n

workqueue\u306e\u4f5c\u6210\u304b\u3089\u5b9f\u884c\u307e\u3067<\/h2>\n

\u5148\u306e\u65e7\u30ab\u30fc\u30cd\u30eb\u89e3\u8aad\u5ba4\u306e\u8aac\u660e\u3092\u3001\u5b9f\u969b\u306b\u5f53\u6642\u306e\u5b9f\u88c5\u3092\u53c2\u7167\u3057\u306a\u304c\u3089\u78ba\u8a8d\u3057\u305f\u3044\u3068\u601d\u3044\u307e\u3059\u3002\u4ee5\u4e0b\u306f\u3001\u65e7WQ\u306b\u304a\u3051\u308bworkqueue_struct\u69cb\u9020\u4f53\u3092\u78ba\u4fdd\u3059\u308bAPI (create_workqueue()<\/a>) \u306e\u5ef6\u9577\u3067\u547c\u3070\u308c\u308b__create_workqueue_key()<\/a>\u306e\u5b9f\u88c5\u306b\u306a\u308a\u307e\u3059\u3002\u65e7\u30ab\u30fc\u30cd\u30eb\u89e3\u8aad\u5ba4\u306e\u8aac\u660e\u306b\u3082\u3042\u3063\u305f\u901a\u308a\u3001\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u306fworkqueue\u5c02\u7528\u30fbCPU\u6bce (L.1035) \u306b\u78ba\u4fdd\u3055\u308c\u308b\u3053\u3068 (L.1039) \u304c\u5206\u304b\u308a\u307e\u3059 (\u4ee5\u5f8cMulti Threaded (MT))\u3002Single Threaded (ST) \u306aworkqueue\u306e\u5834\u5408 (L.1014) \u306b\u306f\u3001CPU\u6bce\u306e\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u306e\u5272\u308a\u5f53\u3066\u306f\u884c\u308f\u308c\u305a\u3001\u30b7\u30b9\u30c6\u30e0\u5168\u4f53\u306b\u5bfe\u3057\u3066\u4e00\u3064\u306e\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u304cworkqueue\u5c02\u7528\u306b\u78ba\u4fdd\u3055\u308c\u307e\u3059 (L.1016)\u3002<\/p>\n

(kernel\/workqueue.c<\/a>)<\/p>\n

   986<\/span> struct<\/span> workqueue_struct *__create_workqueue_key<\/span>(const<\/span> char<\/span> *name,\n   987<\/span>                                                 int<\/span> singlethread,\n   988<\/span>                                                 int<\/span> freezeable,\n   989<\/span>                                                 int<\/span> rt,\n   990<\/span>                                                 struct<\/span> lock_class_key *key,\n   991<\/span>                                                 const<\/span> char<\/span> *lock_name)\n   992<\/span> {\n   993<\/span>         struct<\/span> workqueue_struct *wq;\n   994<\/span>         struct<\/span> cpu_workqueue_struct *cwq;\n   995<\/span>         int<\/span> err = 0<\/span>, cpu;\n   996<\/span>\n   997<\/span>         wq = kzalloc<\/span>(sizeof<\/span>(*wq), GFP_KERNEL);\n   998<\/span>         if<\/span> (!wq)\n   999<\/span>                 return<\/span> NULL<\/span>;\n  1000<\/span>\n  1001<\/span>         wq->cpu_wq = alloc_percpu<\/span>(struct<\/span> cpu_workqueue_struct);\n                ...\n  1009<\/span>         wq->singlethread = singlethread;\n  1010<\/span>         wq->freezeable = freezeable;\n  1011<\/span>         wq->rt = rt;\n                ...\n  1013<\/span>\n  1014<\/span>         if<\/span> (singlethread) {\n  1015<\/span>                 cwq = init_cpu_workqueue<\/span>(wq, singlethread_cpu);\n  1016<\/span>                 err = create_workqueue_thread<\/span>(cwq, singlethread_cpu);\n  1017<\/span>                 start_workqueue_thread<\/span>(cwq, -1<\/span>);\n  1018<\/span>         } else<\/span> {\n                ...\n  1035<\/span>                 for_each_possible_cpu<\/span>(cpu) {\n  1036<\/span>                         cwq = init_cpu_workqueue<\/span>(wq, cpu);\n  1037<\/span>                         if<\/span> (err || !cpu_online<\/span>(cpu))\n  1038<\/span>                                 continue<\/span>;\n  1039<\/span>                         err = create_workqueue_thread<\/span>(cwq, cpu);\n  1040<\/span>                         start_workqueue_thread<\/span>(cwq, cpu);\n  1041<\/span>                 }\n  1042<\/span>                 cpu_maps_update_done<\/span>();\n<\/pre>\n
\u4ee5\u4e0b\u306f\u3001\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u3092queue\u3059\u308b\u305f\u3081\u306eAPI\u3067\u3042\u308bqueue_work()<\/a>\u306e\u5b9f\u88c5\u3067\u3059\u3002\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u306f\u3001MT\u306e\u5834\u5408\u306b\u306fqueue\u3055\u308c\u305fCPU (L.288) \u306b\u304a\u3044\u3066queue\u3055\u308c\u305f\u9806\u306b\u51e6\u7406\u3055\u308c\u3001ST\u306e\u5834\u5408\u306b\u306fCPU\u30b0\u30ed\u30fc\u30d0\u30eb\u306bqueue\u3055\u308c\u305f\u9806\u306b\u51e6\u7406\u3055\u308c\u307e\u3059\u3002\u3053\u306e\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u304cqueue\u3055\u308c\u305fCPU\u306b\u304a\u3044\u3066\u51e6\u7406\u3055\u308c\u308b\u70b9\u306f\u3001WQ\u306e\u4ed5\u69d8\u3068\u3057\u3066\u5f53\u6642\u304b\u3089\u73fe\u5728\u306b\u81f3\u308b\u307e\u3067\u5909\u308f\u3063\u3066\u3044\u307e\u305b\u3093\u3002queue\u3055\u308c\u305f\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u306f\u3001queue\u306b\u4f34\u3044\u8d77\u5e8a\u3057\u305fworkqueue\u306b\u7d10\u3065\u304f (MT\u306e\u5834\u5408\u306b\u306fCPU\u6bce\u306a) \u30ab\u30fc\u30cd\u30eb\u30b9\u30ec\u30c3\u30c9\u306b\u3088\u3063\u3066\u5b9f\u884c\u3055\u308c\u307e\u3059\u3002
\u306a\u304a\u5f53\u6642\u306eMT\u3068ST\u306e\u4f7f\u3044\u5206\u3051\u3068\u3057\u3066\u306f\u3001CPU\u30b0\u30ed\u30fc\u30d0\u30eb\u306b\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u3092\u9010\u6b21\u5b9f\u884c\u3059\u308b\u5fc5\u8981\u304c\u3042\u308b\u7b49\u306e\u5834\u5408\u306b\u306fST\u304c\u4f7f\u7528\u3055\u308c\u3001\u7279\u306b\u660e\u793a\u7684\u306a\u7406\u7531\u304c\u306a\u3044\u5834\u5408\u306fMT\u306aworkqueue\u304c\u4f7f\u7528\u3055\u308c\u3066\u3044\u305f\u3088\u3046\u3067\u3059\u3002<\/p>\n
(kernel\/workqueue.c<\/a>)<\/p>\n
   284<\/span> int<\/span> queue_work<\/span>(struct<\/span> workqueue_struct *wq, struct<\/span> work_struct *work)\n   285<\/span> {\n   286<\/span>         int<\/span> ret;\n   287<\/span> \n   288<\/span>         ret = queue_work_on<\/span>(get_cpu<\/span>(), wq, work);\n   289<\/span>         put_cpu<\/span>();\n   290<\/span> \n   291<\/span>         return<\/span> ret;\n   292<\/span> }\n   293<\/span> EXPORT_SYMBOL_GPL<\/span>(queue_work);\n<\/pre>\n
\u4ee5\u4e0b\u306f\u3001MT\u306b\u304a\u3051\u308bworkqueue\u3068\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u30fb\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u306e\u95a2\u4fc2\u3092\u793a\u3057\u305f\u56f3\u3067\u3059\u3002CPU\u6bce\u306e\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u304cworkqueue\u3054\u3068\u306b\u5272\u308a\u5f53\u3066\u3089\u308c\u3066\u3044\u308b\u3053\u3068\u304c\u308f\u304b\u308a\u307e\u3059\u3002<\/p>\n
<\/span><\/p>\n
\u65e7WQ\u306b\u304a\u3051\u308b\u8ab2\u984c<\/h2>\n
\u6b21\u7ae0\u3067CMWQ\u3092\u7d39\u4ecb\u3059\u308b\u306b\u3042\u305f\u308a\u3001\u3053\u3053\u307e\u3067\u3067\u7c21\u5358\u306b\u78ba\u8a8d\u3057\u305f\u65e7WQ\u306e\u7279\u5fb4\u3092\u8e0f\u307e\u3048\u3066\u3001\u5f53\u6642\u6319\u3052\u3089\u308c\u3066\u3044\u305f\u65e7WQ\u306e\u8ab2\u984c\u3092\u3044\u304f\u3064\u304b\u7d39\u4ecb\u3057\u305f\u3044\u3068\u601d\u3044\u307e\u3059\u3002<\/p>\n
\u5897\u3048\u3059\u304e\u305f\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u3068\u305d\u306e\u5f0a\u5bb3<\/h3>\n
Linux\u3067\u306f\u3001\u30b7\u30b9\u30c6\u30e0\u306b\u304a\u3051\u308b\u6700\u5927PID\u6570\u306e\u30c7\u30d5\u30a9\u30eb\u30c8\u306f32K\u3068\u306a\u3063\u3066\u3044\u307e\u3059\u3002\u524d\u7bc0\u3067\u78ba\u8a8d\u3057\u305f\u901a\u308a\u3001\u65e7WQ\u3067\u306fworkqueue\u3054\u3068\u306b\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u304c\u78ba\u4fdd\u3055\u308c\u3001MT\u306e\u5834\u5408\u306b\u306f\u3055\u3089\u306bCPU\u306e\u6570\u3060\u3051\u78ba\u4fdd\u3055\u308c\u307e\u3059\u3002\u3053\u306e\u3053\u3068\u304b\u3089\u3001\u30b7\u30b9\u30c6\u30e0\u306eCPU\u6570\u5897\u52a0\u306b\u4f34\u3046\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u306e\u5897\u52a0\u306b\u3088\u308bPID\u306e\u67af\u6e07\u304c\u554f\u984c\u3068\u306a\u308a\u307e\u3057\u305f\u3002\u3053\u306e\u5897\u3048\u3059\u304e\u305f\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u306f\u3001PID\u7b49\u306e\u30ea\u30bd\u30fc\u30b9\u6d88\u8cbb\u306e\u539f\u56e0\u306b\u306a\u308b\u4ed6\u3001\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u9593\u306b\u304a\u3051\u308b\u30b3\u30f3\u30c6\u30ad\u30b9\u30c8\u30b9\u30a4\u30c3\u30c1\u306e\u5897\u52a0\u306a\u3069\u6027\u80fd\u3092\u4f4e\u4e0b\u3055\u305b\u308b\u539f\u56e0\u3068\u306a\u308a\u307e\u3059\u3002
\u307e\u305f\u3001MT\u306b\u304a\u3044\u3066CPU\u3054\u3068\u306b\u5272\u308a\u5f53\u3066\u3089\u308c\u308b\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u9593\u3067\u306f\u3001\u304a\u4e92\u3044\u306e\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u306e\u5b9f\u884c\u72b6\u6cc1\u306f\u9023\u643a\u3055\u308c\u305a\u3001\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u306fqueue\u3055\u308c\u305f\u30bf\u30a4\u30df\u30f3\u30b0\u306b\u5fdc\u3058\u3066\u5404CPU\u306e\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u306b\u3088\u3063\u3066\u72ec\u7acb\u306b\u51e6\u7406\u3055\u308c\u3066\u3044\u307e\u3057\u305f\u3002\u3053\u308c\u306f\u3001\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u9593\u306b\u4f9d\u5b58\u95a2\u4fc2\u306f\u3042\u308b\u304c\u3001\u30de\u30eb\u30c1\u30b3\u30a2\u306a\u30b7\u30b9\u30c6\u30e0\u306b\u304a\u3051\u308b\u4e26\u5217\u6027\u3092\u751f\u304b\u3057\u305f\u3044\u30e6\u30fc\u30b6\u30fc\u306b\u3068\u3063\u3066\u4e26\u5217\u6027(MT)\u3068\u9010\u6b21\u5b9f\u884c(ST)\u306e\u30c8\u30ec\u30fc\u30c9\u30aa\u30d5\u306e\u554f\u984c\u3068\u306a\u3063\u3066\u3057\u307e\u3044\u307e\u3059\u3002\u3082\u3057\u3053\u306e\u30c8\u30ec\u30fc\u30c9\u30aa\u30d5\u306b\u7e1b\u3089\u308c\u305a\u3001\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u9593\u306e\u4f9d\u5b58\u95a2\u4fc2\u3092\u8003\u616e\u3057\u306a\u304c\u3089\u4e26\u5217\u306b\u51e6\u7406\u3092\u5b9f\u884c\u3057\u305f\u3044\u5834\u5408\u306b\u306f\u3001\u5f53\u6642\u306efs\/ceph\/messenger.c<\/a>\u306b\u304a\u3044\u3066\u5b9f\u88c5\u3055\u308c\u3066\u3044\u308b\u3088\u3046\u306a\u3001\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u306e\u5b9f\u884c\u72b6\u6cc1\u3092\u30c8\u30e9\u30c3\u30ad\u30f3\u30b0\u3059\u308b\u3088\u3046\u306a\u72ec\u81ea\u306e\u4ed5\u7d44\u307f\u3092\u5b9f\u88c5\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002
\u6b21\u7ae0\u3067\u306f\u3001\u3053\u306e\u30e6\u30fc\u30b9\u30b1\u30fc\u30b9\u306b\u307f\u3089\u308c\u308b\u3088\u3046\u306a\u30e6\u30fc\u30b6\u30fc\u304c\u591a\u304f\u3092\u8003\u616e\u3059\u308b\u5fc5\u8981\u304c\u3042\u3063\u305f\u65e7WQ\u306e\u5074\u9762\u3092\u8e0f\u307e\u3048\u306a\u304c\u3089\u3001CMWQ\u306b\u304a\u3051\u308bConcurrency Management\u306e\u5b9f\u88c5\u3068\u5fc5\u8981\u6027\u306b\u3064\u3044\u3066\u78ba\u8a8d\u3057\u305f\u3044\u3068\u601d\u3044\u307e\u3059\u3002\u306a\u304a\u3001net\/ceph\/messenger.c\u306e\u72ec\u81eaConcurrency Management\u306b\u3064\u3044\u3066\u306f\u3001CMWQ\u306b\u304a\u3044\u3066commit f363e45fd1184<\/a> (“net\/ceph: make ceph_msgr_wq non-reentrant”) \u3067\u89e3\u6d88\u3055\u308c\u3066\u3044\u308b\u306e\u3067\u3001\u6c17\u306b\u306a\u308b\u65b9\u306f\u6b21\u7ae0\u3092\u8aad\u3093\u3060\u5f8c\u306b\u78ba\u8a8d\u3057\u3066\u307f\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n
\u6982\u8981<\/h2>\n
\u73fe\u5728\u306eWQ\u3067\u3042\u308bConcurrency Managed Workqueue (CMWQ) \u306f\u3001\u524d\u7ae0\u3067\u78ba\u8a8d\u3057\u305f\u65e7WQ\u306b\u304a\u3051\u308b\u8ab2\u984c\u3092\u8e0f\u307e\u3048\u305f Concurrency Managed \u306aWQ\u3067\u3059\u3002\u3057\u304b\u3057\u3001CMWQ\u304cv2.6.36\u3067\u5b9f\u88c5\u3055\u308c\u3066\u304b\u3089\u73fe\u5728\u306b\u81f3\u308b\u307e\u3067\u3001WQ\u306b\u306f\u69d8\u3005\u306a\u4fee\u6b63\u304c\u5165\u3063\u3066\u3044\u307e\u3059\u3002\u305d\u306e\u305f\u3081\u3001\u307e\u305a\u672c\u7ae0\u3067\u306f\u65e7WQ\u3068\u306e\u6bd4\u8f03\u304c\u5bb9\u6613\u306aCMWQ\u5b9f\u88c5\u76f4\u5f8c\u306ev2.6.36\u3092\u30d9\u30fc\u30b9\u306b\u3001CMWQ\u304c\u65e7WQ\u3068\u6bd4\u8f03\u3057\u3066 Concurrency Managed \u3067\u3042\u308b\u3053\u3068\u3092\u78ba\u8a8d\u3057\u305f\u3044\u3068\u601d\u3044\u307e\u3059\u3002\u73fe\u5728\u306eWQ\u306b\u3064\u3044\u3066\u306f\u3001\u672c\u7ae0\u3067CMWQ\u304c\u65e7WQ\u3068\u6bd4\u8f03\u3057\u3066 Concurrency Managed \u3067\u3042\u308b\u3053\u3068\u3092\u78ba\u8a8d\u3057\u305f\u4e0a\u3067\u3001\u6700\u5f8c\u306b\u7c21\u5358\u306b\u7d39\u4ecb\u3057\u305f\u3044\u3068\u601d\u3044\u307e\u3059\u3002<\/p>\n
Concurrency Management\u3068\u306f<\/h2>\n
\u524d\u7ae0\u3067\u306f\u3001\u65e7WQ\u306b\u304a\u3044\u3066\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u304c\u3001workqueue\u3054\u3068\u306b\u78ba\u4fdd\u3055\u308c\u308b\u3053\u3068\u3092\u78ba\u8a8d\u3057\u307e\u3057\u305f\u3002CMWQ\u306b\u304a\u3044\u3066\u306f\u3001workqueue\u3054\u3068\u306b\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u306f\u78ba\u4fdd\u3055\u308c\u305a\u3001\u3042\u3089\u304b\u3058\u3081\u7528\u610f\u3055\u308c\u3066\u3044\u308bworkqueue global\u306a\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u304c\u5272\u308a\u5f53\u3066\u3089\u308c\u307e\u3059\u3002\u3053\u306eworkqueue global\u306a\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u306f\u3001CMWQ\u3067\u65b0\u305f\u306b\u5c0e\u5165\u3055\u308c\u305fper cpu\u306aglobal_cwq<\/a>\u69cb\u9020\u4f53 (\u4ee5\u964dgcwq) \u306b\u7d10\u4ed8\u3051\u3089\u308c\u3066\u3044\u307e\u3059\u3002gcwq\u306b\u306f\u3001\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u306b\u52a0\u3048\u3066\u3001\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u3082workqueue\u306b\u95a2\u308f\u3089\u305a\u7d10\u4ed8\u3051\u3089\u308c\u307e\u3059\u3002\u305d\u306e\u305f\u3081\u3001\u65e7WQ\u306b\u304a\u3044\u3066workqueue\u3054\u3068\u306b\u7ba1\u7406\u3055\u308c\u3066\u3044\u305f\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u3084\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u306f\u3001CMWQ\u3067\u306fCPU\u5358\u4f4d\u3067\u7ba1\u7406\u3055\u308c\u307e\u3059\u3002<\/p>\n
(kernel\/workqueue.c<\/a>)<\/p>\n
   143<\/span> \n\n\n\n\n   148<\/span> struct<\/span> global_cwq {\n   149<\/span>         spinlock_t              lock;           \n   150<\/span>         struct<\/span> list_head        worklist;       \n   151<\/span>         unsigned<\/span> int<\/span>            cpu;            \n   152<\/span>         unsigned<\/span> int<\/span>            flags;          \n   153<\/span> \n   154<\/span>         int<\/span>                     nr_workers;     \n<\/pre>\n
\u4ee5\u4e0b\u306f\u3001WQ\u3092\u78ba\u4fdd\u3059\u308b\u969b\u306b\u547c\u3070\u308c\u308b__alloc_workqueue_key()<\/a>\u306e\u629c\u7c8b\u3067\u3059\u3002\u65e7WQ\u306e__create_workqueue_key()<\/a>\u3068\u6bd4\u8f03\u3059\u308b\u3068\u5206\u304b\u308b\u3068\u304a\u308a\u3001CMWQ\u306b\u304a\u3044\u3066\u306fworkqueue\u3054\u3068\u306e\u65b0\u305f\u306a\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u306e\u78ba\u4fdd\u306f\u884c\u308f\u308c\u305a\u3001per cpu\u306agcwq\u304c\u7d10\u4ed8\u3051\u3089\u308c\u308b\u306e\u307f (L.2799) \u3068\u306a\u308a\u307e\u3059\u3002<\/p>\n
(kernel\/workqueue.c<\/a>)<\/p>\n
  2757<\/span> struct<\/span> workqueue_struct *__alloc_workqueue_key<\/span>(const<\/span> char<\/span> *name,\n  2758<\/span>                                                unsigned<\/span> int<\/span> flags,\n  2759<\/span>                                                int<\/span> max_active,\n  2760<\/span>                                                struct<\/span> lock_class_key *key,\n  2761<\/span>                                                const<\/span> char<\/span> *lock_name)\n  2762<\/span> {\n  2763<\/span>         struct<\/span> workqueue_struct *wq;\n  2764<\/span>         unsigned<\/span> int<\/span> cpu;\n...\n  2794<\/span>         for_each_cwq_cpu<\/span>(cpu, wq) {\n  2795<\/span>                 struct<\/span> cpu_workqueue_struct *cwq = get_cwq<\/span>(cpu, wq);\n  2796<\/span>                 struct<\/span> global_cwq *gcwq = get_gcwq<\/span>(cpu);\n  2797<\/span> \n  2798<\/span>                 BUG_ON<\/span>((unsigned<\/span> long<\/span>)cwq & WORK_STRUCT_FLAG_MASK);\n  2799<\/span>                 cwq->gcwq = gcwq;\n  2800<\/span>                 cwq->wq = wq;\n  2801<\/span>                 cwq->flush_color = -1<\/span>;\n  2802<\/span>                 cwq->max_active = max_active;\n  2803<\/span>                 INIT_LIST_HEAD<\/span>(&cwq->delayed_works);\n  2804<\/span>         }\n<\/pre>\n
\u3053\u3053\u307e\u3067\u3092\u6574\u7406\u3059\u308b\u3068\u3001\u65e7WQ\u3067\u306fworkqueue\u3054\u3068\u306b\u5272\u308a\u5f53\u3066\u3089\u308c\u3066\u3044\u305f\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u306f\u3001CMWQ\u3067\u306f\u4ee5\u4e0b\u56f3\u306e\u3088\u3046\u306b\u5404CPU\u306bworkqueue global\u306b\u5272\u308a\u5f53\u3066\u3089\u308c\u307e\u3059\u3002\u6b21\u7bc0\u3067\u306f\u3001\u3053\u306egcwq\u5c0e\u5165\u306b\u4f34\u3046workqueue\u3068\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u306e\u95a2\u4fc2\u3092\u8e0f\u307e\u3048\u3066\u3001\u524d\u7ae0\u3067\u6319\u3052\u305f\u65e7WQ\u306e\u8ab2\u984c\u304c\u3069\u306e\u3088\u3046\u306bCMWQ\u306b\u304a\u3044\u3066\u89e3\u6d88\u3055\u308c\u305f\u304b\u3092\u78ba\u8a8d\u3057\u307e\u3059\u3002<\/p>\n
<\/span><\/p>\n
Concurrency Management\u306e\u5177\u4f53\u4f8b<\/h3>\n
Concurrency Management\u306b\u6c42\u3081\u3089\u308c\u308b\u8981\u4ef6\u306f\u3001\u4ee5\u4e0b\u30c9\u30ad\u30e5\u30e1\u30f3\u30c6\u30fc\u30b7\u30e7\u30f3\u306b\u3082\u3042\u308b\u901a\u308a\u3001\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9 (Execution Context) \u304c\u5fc5\u8981\u4ee5\u4e0a (minimal) \u306b\u5b58\u5728\u305b\u305a\u3001\u304b\u3064\u5b9f\u884c\u304c\u6ede\u308a\u306a\u304f (sufficient) \u884c\u308f\u308c\u308b\u3053\u3068\u3067\u3059\u3002\u672c\u7bc0\u3067\u306f\u3001\u3053\u306eExecution Context\u3067\u3042\u308b\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u304cminimal but sufficient level\u306a\u72b6\u614b\u3067\u3042\u308b\u3068\u3044\u3046\u8981\u4ef6\u304c\u6e80\u305f\u3055\u308c\u306a\u3044\u5177\u4f53\u7684\u306a\u30b1\u30fc\u30b9\u3092\u901a\u3057\u3066\u3001Concurrency Management\u306b\u3064\u3044\u3066\u8003\u3048\u3066\u307f\u305f\u3044\u3068\u601d\u3044\u307e\u3059\u3002<\/p>\n
(Documentation\/core-api\/workqueue.rst<\/a>)<\/p>\n
\n
For any thread pool implementation, managing the concurrency level
(how many execution contexts are active) is an important issue.  cmwq
tries to keep the concurrency at a minimal but sufficient level.
Minimal to save resources and sufficient in that the system is used at
its full capacity.<\/p>\n<\/blockquote>\n
WQ_CPU_INTENSIVE<\/h4>\n
\u307e\u305a\u306f\u3001\u5b9f\u884c\u6642\u9593\u304c\u9577\u3044\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0A\u3068\u3001\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0A\u3068\u306f\u7570\u306a\u308bworkqueue\u306b\u5c5e\u3059\u308b\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0B\u304c\u540c\u3058CPU\u306bqueue\u3055\u308c\u305f\u72b6\u614b\u3092\u8003\u3048\u3066\u307f\u307e\u3059\u3002\u3053\u306e\u5834\u5408\u3001\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0B\u306f\u3001\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0A\u306e\u5b8c\u4e86\u3092\u5f85\u3061\u7d9a\u3051\u308b\u3053\u3068\u306b\u306a\u308a\u307e\u3059\u3002\u65e7WQ\u306b\u304a\u3044\u3066\u306f\u3001\u5404WQ\u304c\u5404\u3005\u306e\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u3092\u5272\u308a\u5f53\u3066\u3089\u308c\u3066\u3044\u305f\u3053\u3068 (Execution context\u304cmore than sufficient, resource\u304cwasted\u306a\u72b6\u614b) \u304b\u3089\u3001\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0A\u306e\u51e6\u7406\u306b\u6642\u9593\u304c\u304b\u304b\u308b\u3088\u3046\u306a\u5834\u5408\u3067\u3082\u3001\u51e6\u7406\u3057\u3066\u3044\u308b\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u306f\u30b7\u30b9\u30c6\u30e0\u306e\u30b9\u30b1\u30b8\u30e5\u30fc\u30e9\u306b\u3088\u308a\u30b9\u30b1\u30b8\u30e5\u30fc\u30eb\u30a2\u30a6\u30c8\u3055\u308c\u3001\u3044\u305a\u308c\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0B\u3092\u51e6\u7406\u3059\u308b\u305f\u3081\u306e\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u304c\u30b9\u30b1\u30b8\u30e5\u30fc\u30ea\u30f3\u30b0\u3055\u308c\u307e\u3057\u305f\u3002\u3057\u304b\u3057\u3001CMWQ\u306b\u304a\u3044\u3066\u306f\u3001\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u304c\u5171\u6709\u3055\u308c\u308b\u3053\u3068\u304b\u3089\u3001\u65e7WQ\u306e\u3088\u3046\u306b\u30b9\u30b1\u30b8\u30e5\u30fc\u30e9\u983c\u307f\u3067\u306f\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0B\u306f\u5b9f\u884c\u3055\u308c\u307e\u305b\u3093\u3002\u3053\u306e\u3088\u3046\u306aExecution Context\u304cless than sufficient\u306a\u72b6\u614b\u306b\u306a\u3063\u305f\u5834\u5408\u3001\u65b0\u305f\u306aExecution Context (\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9) \u304c\u5fc5\u8981\u3068\u306a\u308a\u307e\u3059\u3002WQ_CPU_INTENSIVE<\/a>\u306f\u3001\u3053\u306e\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0A\u306e\u3088\u3046\u306a\u5b9f\u884c\u6642\u9593\u304c\u304b\u304b\u308b\u3067\u3042\u308d\u3046\u3068\u3055\u308c\u308b\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u306b\u5bfe\u3057\u3066\u7528\u3044\u3089\u308c\u308b\u30d5\u30e9\u30b0\u3068\u306a\u308a\u307e\u3059\u3002\u3053\u308c\u304b\u3089\u5b9f\u884c\u3055\u308c\u308b\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u304cWQ_CPU_INTENSIVE\u6307\u5b9a\u3055\u308c\u3066\u3044\u305f\u5834\u5408 (L.1813) \u306b\u306f\u3001\u7d9a\u304f\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u3092\u51e6\u7406\u3059\u308b\u305f\u3081\u306e\u65b0\u305f\u306a\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u3092\u8d77\u5e8a\u3057\u307e\u3059 (Execution Context\u3092minimal but sufficient level\u306a\u72b6\u614b\u306b\u4fdd\u3064)\u3002<\/p>\n
(kernel\/workqueue.c<\/a>)<\/p>\n
  1750<\/span> static<\/span> void<\/span> process_one_work<\/span>(struct<\/span> worker *worker, struct<\/span> work_struct *work)\n    ...\n  1809<\/span>         \n\n\n\n  1813<\/span>         if<\/span> (unlikely<\/span>(cpu_intensive))\n  1814<\/span>                 worker_set_flags<\/span>(worker, WORKER_CPU_INTENSIVE, true<\/span>);\n<\/pre>\n
\u8d77\u5e8a\u3059\u308b\u304b\u3069\u3046\u304b\u306e\u5224\u5b9a\u304c\u884c\u308f\u308c\u308bworker_set_flags()<\/a>\u3067\u306f\u3001\u3053\u306e\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u4ee5\u5916\u306e\u30ed\u30fc\u30ab\u30ebCPU\u306b\u304a\u3051\u308b\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u306e\u6709\u7121 (L.755)\u30fb\u51e6\u7406\u5f85\u3061\u306e\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u306e\u6709\u7121 (L.756) \u3092\u78ba\u8a8d\u3057\u307e\u3059\u3002\u30ed\u30fc\u30ab\u30ebCPU\u3067\u5b9f\u884c\u3055\u308c\u3066\u3044\u308b\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u304c\u7121\u304f\u3001\u51e6\u7406\u5f85\u3061\u306e\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u304c\u6709\u308b\u5834\u5408\u306b\u306f\u3001\u65b0\u305f\u306b\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u3092\u8d77\u5e8a\u3057\u307e\u3059 (L.757) \u3002<\/p>\n
(kernel\/workqueue.c<\/a>)<\/p>\n
   738<\/span> static<\/span> inline<\/span> void<\/span> worker_set_flags<\/span>(struct<\/span> worker *worker, unsigned<\/span> int<\/span> flags,\n   739<\/span>                                     bool<\/span> wakeup)\n   740<\/span> {\n   741<\/span>         struct<\/span> global_cwq *gcwq = worker->gcwq;\n   742<\/span> \n   743<\/span>         WARN_ON_ONCE<\/span>(worker->task != current);\n   744<\/span> \n   745<\/span>         \n\n\n\n\n   750<\/span>         if<\/span> ((flags & WORKER_NOT_RUNNING) &&\n   751<\/span>             !(worker->flags & WORKER_NOT_RUNNING)) {\n   752<\/span>                 atomic_t *nr_running = get_gcwq_nr_running<\/span>(gcwq->cpu);\n   753<\/span> \n   754<\/span>                 if<\/span> (wakeup) {\n   755<\/span>                         if<\/span> (atomic_dec_and_test<\/span>(nr_running) &&\n   756<\/span>                             !list_empty<\/span>(&gcwq->worklist))\n   757<\/span>                                 wake_up_worker<\/span>(gcwq);\n   758<\/span>                 } else<\/span>\n   759<\/span>                         atomic_dec<\/span>(nr_running);\n   760<\/span>         }\n   761<\/span> \n   762<\/span>         worker->flags |= flags;\n   763<\/span> }\n<\/pre>\n
\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u304csleep\u3057\u305f\u5834\u5408<\/h4>\n
Execution Context\u304cminimal but sufficient level\u306a\u72b6\u614b\u3067\u306f\u306a\u304f\u306a\u308b\u4ed6\u306e\u30b1\u30fc\u30b9\u3068\u3057\u3066\u3001\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u304csleep\u3057\u305f\u5834\u5408\u304c\u6319\u3052\u3089\u308c\u307e\u3059\u3002\u3053\u306e\u5834\u5408\u3001\u524d\u7bc0\u3068\u540c\u69d8\u306bCMWQ\u306b\u304a\u3044\u3066\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u304cworkqueue\u9593\u3067\u5171\u6709\u3055\u308c\u3066\u3044\u308b\u3053\u3068\u304b\u3089\u3001sleep\u3057\u305f\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u306b\u7d9a\u304f\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u306f\u51e6\u7406\u3055\u308c\u307e\u305b\u3093\u3002\u3053\u306e\u3088\u3046\u306a\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u306esleep\u306b\u4f34\u3046Execution Context\u304cless than sufficient\u306a\u72b6\u614b\u306b\u306a\u3063\u305f\u5834\u5408\u306e\u305f\u3081\u3001CMWQ\u3067\u306f\u30b9\u30b1\u30b8\u30e5\u30fc\u30e9\u306b\u5bfe\u3057\u3066\u30d5\u30c3\u30af\u3092\u7528\u610f\u3057\u3066\u3044\u307e\u3059\u3002\u30b9\u30b1\u30b8\u30e5\u30fc\u30e9\u3067\u306f\u3001sleep\u72b6\u614b\u306b\u79fb\u884c\u3059\u308b\u30b9\u30ec\u30c3\u30c9\u304c\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u3067\u3042\u308b\u5834\u5408 (L.3778)\u3001\u65b0\u305f\u306b\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u3092\u8d77\u5e8a\u3059\u308b\u304b\u3069\u3046\u304b\u78ba\u8a8d\u3057\u307e\u3059 (L.3782)\u3002wq_worker_sleeping()<\/a> (L.3781)\u3067\u306f\u3001worker_set_flags()<\/a>\u540c\u69d8\u306e\u78ba\u8a8d\u3092\u884c\u3044\u3001\u30ed\u30fc\u30ab\u30ebCPU\u3067\u5b9f\u884c\u3055\u308c\u3066\u3044\u308b\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u304c\u7121\u304f\u3001\u51e6\u7406\u5f85\u3061\u306e\u30ef\u30fc\u30af\u30a2\u30a4\u30c6\u30e0\u304c\u6709\u308b\u5834\u5408\u306b\u306f\u3001\u65b0\u305f\u306b\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u3092\u8d77\u5e8a\u3057\u307e\u3059 (L.3783)\u3002<\/p>\n
(kernel\/sched.c<\/a>)<\/p>\n
  3739<\/span> \n\n\n  3742<\/span> asmlinkage void<\/span> __sched schedule<\/span>(void<\/span>)\n                ...\n  3772<\/span>                         \n\n\n\n\n\n  3778<\/span>                         if<\/span> (prev->flags & PF_WQ_WORKER) {\n  3779<\/span>                                 struct<\/span> task_struct *to_wakeup;\n  3780<\/span> \n  3781<\/span>                                 to_wakeup = wq_worker_sleeping<\/span>(prev, cpu);\n  3782<\/span>                                 if<\/span> (to_wakeup)\n  3783<\/span>                                         try_to_wake_up_local<\/span>(to_wakeup);\n  3784<\/span>                         }\n<\/pre>\n
\u73fe\u5728\u306eWQ<\/h2>\n
\u524d\u7bc0\u306b\u304a\u3044\u3066\u7d39\u4ecb\u3057\u305fCMWQ\u3067\u306f\u3001workqueue\u306b\u306f\u3042\u3089\u304b\u3058\u3081workqueue\u30b0\u30ed\u30fc\u30d0\u30eb\u306b\u78ba\u4fdd\u3055\u308c\u3066\u3044\u308b\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u304c\u5272\u308a\u5f53\u3066\u3089\u308c\u3001workqueue\u306b\u5272\u308a\u5f53\u3066\u308b\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u306enice\u5024\u3068\u3044\u3063\u305f\u5c5e\u6027\u3092\u30e6\u30fc\u30b6\u30fc\u304c\u6307\u5b9a\u3059\u308b\u3053\u3068\u306f\u3067\u304d\u307e\u305b\u3093\u3067\u3057\u305f\u3002\u3057\u304b\u3057\u3001\u73fe\u5728\u306eWQ\u3067\u306f\/sys\/devices\/virtual\/workqueue\/WQ_NAME\/<\/code>\u3084apply_workqueue_attrs()<\/a>\u3092\u901a\u3057\u3066\u3001workqueue\u306b\u5272\u308a\u5f53\u3066\u308b\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u306e\u5c5e\u6027\u3092\u6307\u5b9a\u30fb\u5909\u66f4\u3059\u308b\u3053\u3068\u3067\u304d\u307e\u3059\u3002\u30e6\u30fc\u30b6\u30fc\u304b\u3089\u6307\u5b9a\u3055\u308c\u305f\u5c5e\u6027\u3092\u4fdd\u6301\u3059\u308b\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u304c\u5b58\u5728\u3057\u306a\u3044\u5834\u5408\u306b\u306f\u3001\u65b0\u305f\u306b\u6307\u5b9a\u3055\u308c\u305f\u5c5e\u6027\u3092\u4fdd\u6301\u3059\u308b\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u304c\u4f5c\u6210\u3055\u308c\u307e\u3059\u3002<\/p>\n
$ ls \/sys\/devices\/virtual\/workqueue\/writeback\/\naffinity_scope  affinity_strict  cpumask  max_active  nice  per_cpu  power  subsystem  uevent<\/pre>\n
\u305d\u306e\u305f\u3081\u3001\u73fe\u5728\u306eWQ\u306b\u304a\u3051\u308bConcurrency Management\u306f\u5c5e\u6027\u3092\u5171\u6709\u3057\u3066\u3044\u308b\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u9593\u3067\u884c\u308f\u308c\u307e\u3059\u3002\u306a\u304a\u3001\u5404\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u3068CPU\u306e\u95a2\u4fc2\u306f\u3053\u308c\u307e\u3067\u3068\u5909\u308f\u3089\u306a\u3044\u305f\u3081\u3001\u524d\u7bc0\u3067\u7d39\u4ecb\u3057\u305f\u4e3b\u306a\u69cb\u9020\u4f53\u306f\u3001\u73fe\u5728\u306eWQ\u306b\u304a\u3044\u3066\u306f\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u5bfe\u5fdc\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n
struct global_cpu_workqueue -> struct worker_pools\nstruct cpu_workqueue_struct -> struct pool_workqueue<\/pre>\n
\u7570\u306a\u308b\u5c5e\u6027\u304c\u4e0e\u3048\u3089\u308c\u305f\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u304c\uff12\u3064\u3042\u308b\u5834\u5408 (ATTR 1\u3068ATTR 2) \u306b\u306f\u3001\u305d\u308c\u305e\u308c\u306e\u30ef\u30fc\u30ab\u30fc\u30b9\u30ec\u30c3\u30c9\u3068CPU\u306e\u5bfe\u5fdc\u306f\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n
<\/span><\/p>\n
\u672c\u8a18\u4e8b\u3067\u306f\u3001WQ\u306e\u73fe\u5728\u306e\u5b9f\u88c5\u306b\u81f3\u308b\u307e\u3067\u306e\u7d4c\u7def\u3092\u8fbf\u3063\u3066\u304d\u307e\u3057\u305f\u3002\u6700\u5f8c\u306b\u3001WQ\u304c\u5c0e\u5165\u3055\u308c\u308b\u306b\u81f3\u3063\u305f\u80cc\u666f\u305d\u308c\u81ea\u4f53\u306b\u3064\u3044\u3066\u3001\u6628\u5e74\u306etasklet\u306b\u95a2\u3059\u308b\u53d6\u308a\u7d44\u307f\u3092\u4ea4\u3048\u3066\u4f59\u8ac7\u7684\u306b\u53d6\u308a\u6319\u3052\u305f\u3044\u3068\u601d\u3044\u307e\u3059\u3002<\/p>\n
WQ\u3078\u306etasklet\u7d71\u5408<\/h2>\n
\u3053\u308c\u307e\u3067\u306b\u3082tasklet\u306b\u3064\u3044\u3066\u306f\u3001\u30ea\u30d5\u30a1\u30af\u30bf\u30ea\u30f3\u30b0\u304c\u5fc5\u8981\u3068\u3057\u3066\u5ea6\u3005\u8b70\u8ad6\u304c\u884c\u308f\u308c\u3066\u304d\u307e\u3057\u305f\u304c\u3001WQ\u306b\u7d71\u5408\u3055\u308c\u308b\u3068\u3044\u3046\u5f62\u3067\u6628\u5e74 (\u3064\u3044\u306b\uff1f) \u624b\u304c\u52a0\u3048\u3089\u308c\u307e\u3057\u305f\u3002tasklet\u304c\u5c0e\u5165\u3055\u308c\u308b\u306b\u81f3\u3063\u305f\u7d4c\u7def\u3092\u9061\u308b\u3068\u3001\u65e7\u30ab\u30fc\u30cd\u30eb\u89e3\u8aad\u5ba4\u306b\u3082\u8aac\u660e\u3055\u308c\u3066\u3044\u308b\u3088\u3046\u306b\u3001WQ\u3068\u306f\u5207\u308a\u96e2\u305b\u306a\u3044\u95a2\u4fc2\u306b\u3042\u308a\u307e\u3059\u3002<\/p>\n
\n
Linux\u30ab\u30fc\u30cd\u30eb2.4\u4ee5\u524d\u306f\u3001taskqueue\u3068\u547c\u3070\u308c\u308b\u9045\u5ef6\u51e6\u7406\u306e\u4ed5\u7d44\u307f\u304c\u5229\u7528\u3055\u308c\u3066\u3044\u307e\u3057\u305f\u3002\u5272\u308a\u8fbc\u307f\u30b3\u30f3\u30c6\u30ad\u30b9\u30c8\u306e\u9045\u5ef6\u51e6\u7406\u3082\u30d7\u30ed\u30bb\u30b9\u30b3\u30f3\u30c6\u30ad\u30b9\u30c8\u306e\u9045\u5ef6\u51e6\u7406\u3082\u3001\u3053\u306etaskqueue\u3092\u5229\u7528\u3057\u3066\u5b9f\u73fe\u3057\u3066\u3044\u307e\u3057\u305f\u3002Linux\u30ab\u30fc\u30cd\u30eb2.6\u3067\u306f\u3001\u30de\u30eb\u30c1\u30d7\u30ed\u30bb\u30c3\u30b5\u52d5\u4f5c\u6642\u306e\u52b9\u7387\u5316\u306e\u305f\u3081\u306b\u3001\u5272\u308a\u8fbc\u307f\u30b3\u30f3\u30c6\u30ad\u30b9\u30c8\u306e\u9045\u5ef6\u51e6\u7406\u306f\u3059\u3079\u3066tasklet\u306b\u66f8\u304d\u76f4\u3057\u3001\u30d7\u30ed\u30bb\u30b9\u30b3\u30f3\u30c6\u30ad\u30b9\u30c8\u306e\u9045\u5ef6\u51e6\u7406\u306e\u305f\u3081\u306bworkqueue\u3092\u5c0e\u5165\u3057\u307e\u3057\u305f\u3002<\/p>\n<\/blockquote>\n
\u4eca\u56de\u306e\u7d71\u5408\u306e\u304d\u3063\u304b\u3051\u3068\u306a\u3063\u305f\u306e\u306f\u3001tasklet\u5b9f\u884c\u5f8c\u306b\u767a\u751f\u3059\u308buse-after-free\u304c\u554f\u984c *1<\/a> \u3068\u306a\u3063\u305f\u3053\u3068\u3067\u3057\u305f\u304c\u3001\u904e\u53bb\u306b\u306ftasklet\u304c\u30bd\u30d5\u30c8\u5272\u308a\u8fbc\u307f\u30b3\u30f3\u30c6\u30ad\u30b9\u30c8\u3067\u5b9f\u884c\u3055\u308c\u308b\u3053\u3068\u81ea\u4f53\u304c\u3001\u6b63\u78ba\u306a\u30b9\u30b1\u30b8\u30e5\u30fc\u30ea\u30f3\u30b0\u3092\u59a8\u3052\u308b\u30fb\u30d7\u30ed\u30bb\u30b9\u306e\u51e6\u7406\u5b8c\u4e86\u3092\u9045\u3089\u305b\u308b\u539f\u56e0\u306b\u306a\u308b\u3068\u3057\u3066\u554f\u984c\u306b\u6319\u3052\u3089\u308c\u308b\u3053\u3068\u3082\u3042\u3063\u305f\u3088\u3046\u3067\u3059\u3002\u4eca\u56de\u306e\u7d71\u5408\u306b\u3088\u3063\u3066\u3001tasklet\u306fAPI\u3068\u3057\u3066\u306f\u5ec3\u6b62\u3055\u308c\u3001\u518d\u3073WQ\u3068\u7d71\u5408\u3055\u308c\u307e\u3057\u305f\u304c\u3001tasklet\u305f\u308b\u6240\u4ee5\u3067\u3042\u308b\u30bd\u30d5\u30c8\u5272\u308a\u8fbc\u307f\u30b3\u30f3\u30c6\u30ad\u30b9\u30c8\u306b\u304a\u3051\u308b\u51e6\u7406\u306e\u9045\u5ef6\u5b9f\u884c\u306f\u4ed5\u7d44\u307f\u3068\u3057\u3066\u6b8b\u3055\u308c\u307e\u3057\u305f\u3002\u3053\u306e\u30bd\u30d5\u30c8\u5272\u308a\u8fbc\u307f\u51e6\u7406\u306b\u304a\u3044\u3066\u767a\u751f\u3059\u308b\u9045\u5ef6\u306b\u5bfe\u3057\u3066\u3001\u4eca\u5f8c\u30ab\u30fc\u30cd\u30eb\u304c\u3069\u3046\u53d6\u308a\u7d44\u3080\u306e\u304b\u7b46\u8005\u306f\u6c17\u306b\u306a\u3063\u3066\u3044\u307e\u3059\u3002<\/p>\n<\/div>\n