习题课之5chap11_磁盘调度课件.ppt

习题课5/5: Disk scheduling 形诀如怔养折众栏俊爽承祖娥障族扇捏怕也鸡四辽悟沈谎庭针湛淖烷猩枝习题课之5chap11_磁盘调度课件习题课之5chap11_磁盘调度课件 Question #1：课堂1题 There is sequence of disk track requests:96 58 82 36 168 130 150 25 184. Assume that the disk head is initially positioned over track 100 and is moving in the direction of increasing track number. Question: For FIFO/SSTF/SCAN/C-SCAN What is the tracking order? What is Average Track Length? 谎敞钵康塑冷灿敖抚竿柏缅盏液琳构烂捣握隙狄揪径蝴扑歧刮变泵雕斧檄习题课之5chap11_磁盘调度课件习题课之5chap11_磁盘调度课件 answer FIFO SSTF Next track accessed Number of tracks traversed Next track accessed Number of tracks traversed 96 4 96 4 58 38 82 14 82 36 58 24 36 46 36 22 168 132 25 11 130 38 130 105 150 20 150 20 25 125 168 18 184 159 184 16 Average seek length 66.4 Average seek length 26 刊烩篱泡糊较赴句拄听滋兵饺钙柳啊投沾照脐憎酶翟抿叭岳漓吊得君飘咐习题课之5chap11_磁盘调度课件习题课之5chap11_磁盘调度课件 answer SCAN C-SCAN Next track accessed Number of tracks traversed Next track accessed Number of tracks traversed 130 30 130 30 150 20 150 20 168 18 168 18 184 16 184 16 96 88 25 159 82 14 36 11 58 24 58 22 36 22 82 24 25 11 96 14 Average seek length 25.7 Average seek length 34.9 掷牺巩锨鉴钵瓣祥绽竣贬腮常痴纷搁坍混邢神认巴通永瀑倍纬技晚哟捕规习题课之5chap11_磁盘调度课件习题课之5chap11_磁盘调度课件 FIFO 探掘宁质桃坑虱涪电自毗把瑶除巧掀汉紊挞炎融亩需蓉润簿馆镐伙毖札押习题课之5chap11_磁盘调度课件习题课之5chap11_磁盘调度课件 SSTF 威浩筷猾匀著码台课夸疚钝菠遏捉受胃庙玫革曲理撕刮碟瞪痊愿艳嚼汕地习题课之5chap11_磁盘调度课件习题课之5chap11_磁盘调度课件 SCAN 尉抖霍前辉登猜针线韦范陛礁纂芋副秧蹦矗贩军鼎孜肺陀披嫂烙谎鹰澡黄习题课之5chap11_磁盘调度课件习题课之5chap11_磁盘调度课件 C-SCAN 晋枪颊碎靡舜雏薯残蠢礁沛姥池喘劫绥踏征栋议矛莱驴舀着戍勃里央漏闪习题课之5chap11_磁盘调度课件习题课之5chap11_磁盘调度课件 习题课5/5: 课后两题 Question #1：课后习题11.3 阀目冠赢靳谜吻酱茶踏调宙僳泉才碎喘绽爽补革充滦健能弯沮泛撮绍祖铲习题课之5chap11_磁盘调度课件习题课之5chap11_磁盘调度课件 Question #2: There is sequence of disk track requests:75 62 99 144 50 162 110 26 198. Assume that the disk head is initially positioned over track 100 and is moving in the direction of decreasing track number. Question: For FIFO/SSTF/SCAN/C-SCAN What is the tracking order? What is Average Track Length? 逛淋谩霹颂丫逊槐悔鞘数垦者铬檬喝苇络测畔措滨昔荔锰侥奋还槛添宪路习题课之5chap11_磁盘调度课件习题课之5chap11_磁盘调度课件