PowerPoint 5.1 I/O 5.2 I/O 5.3 5.4 I/O 5.5 5.6 5.1 I/O 5.1.1 I/O 1I/O 1) 2) 3) 4) (2) (3) () 2 5-1 1) 2) 5.1.2 1 1) 2) 3) 4) 5) 6) 2 1) 2) 3) I/O 5-2 5.1.3 I/O I/OI/O(I/O)I/OI/O: I/OCPU 2 5-3ABCDE…N…AA1A2A3…BB1B2B3…()A1B1C1D1 …A2B2C2D2 … A3B3C3D3 … 5-3 2) (Block Selector Channel) 3) (Block Multiplexor Channel) 3“” 5-4 I/O “”5-512341121“” 5-5 I/O 5.1.4 5-6 I/O 1ISAEISA 2) EISA(Extended ISA) 2(Local Bus) 1) VESA(Video Electronic Standard Association) VESA32132 Mb/s2090486VESA24Pentium 2) PCI(Peripheral Component Interface) 5.2 I/O 5.2.1 I/O 5-7 I/O 5.2.2 I/O I/OCPUCPUI/OCPUCPUI/O100 ms0.1 msI/OCPU99.9 ms—CPU99.9 ms0.1 msCPU 5.2.3 (DMA)I/O (1) CPUI/O (2) 2DMA 5-8 DMA DMA (2) (MAR) (3) (DR) 3DMA DMA()(DR)()MARMAR1DC11DC0()DMA5-9DMA 5-9 DMA 5.2.4 I/O 1I/O I/ODMACPU()()CPUI/OCPU()I/OI/OI/OCPUI/O 2 (2) ()() (3) () (5) RR=0R=1 81389280103411731405830588960430056500 5.3.1 (2) CPUCPU5-10(a)CPU9.6 Kb/sCPU9.6 Kb/s100 μsCPUCPU100 μs8()5-10(b)CPU1/885-10(c)CPU800 μs 5-10 5.3.2 5-11 2(Double Buffer) 5-12 5-13 5.3.3 1 5-14 2 (2) ReleasebufCReleasebufC()CRReleasebufG 3 (1) NextiNextgRReleasebuf (2) NextgNextiReleasebufI/O 5.3.4 1 : () : (3) outqF(outq)L(outq) 2GetbufPutbuf (1) Addbuf(typenumber)numberBtype MS(type)RS(type)GetbufPutbuf Procedure Getbuf(type) 3 5-15 (1) Getbuf(emq)emqhinPutbuf(inqhin)inq (2) Getbuf(inq)inq(sin)Putbuf(emqsin)emq (3) Getbuf(emq)emqhoutPutbuf(outqhout)outq (4) Getbuf(outq)soutPutbuf(emqsout) 5.4 I/O I/O I/O I/O 1) OSI/O 2) 3) 4) 5) 6) I/O I/OI/OI/OI/OI/O I/OI/O 5-16(I/O) (1) I/O (2) (3) I/O (4) CPU 5-16 I/O 5.4.2 1() 2CPU 5-17 3 4 5 I/OI/OI/O4I/OUNIX45-18 5-18 5.4.3 1 I/O (2) I/OI/O (3) I/OI/OI/O (4) 2 (2) I/OI/O (3) () 3 : (3) I/OI/OI/ODMA (5) (6) MMUDMA 4 “” 2) I/O 3) 4) 5) 6) I/O I/OI/OI/O/() 5.4.4 1 1) 2) I/O 2 (1) : (2) ()readwrite 3 1) 5-19 2) LUT 5.4.5 I/O CCwriteI/OCC 5.5.1 1(DCT) 5-20 typedeviceid (2) /“1”“1” (3) DCT (4) 2 5-21 COCTCHCTSDT 5.5.2 : 1 (1) (2) (3) () 2 3 1) 2) 5.5.3 1 1) 2) 2 1) 2) 5.5.4 SPOOLing 1SPOOLing 2SPOOLing SPOOLing (2) CPU (3) SPiSPoI/OSPiCPUSPo 5-22 SPOOLing 3 4SPOOLing (2) SPOOLingI/O (3) SPOOLing 5.6 5.6.1 1 5-23 10 GB816()16 383()63 5-24()30600512 (2) 512 5-24 2 1) 2) 3 1) Ts Ts = m ×n +s mm=0.2m≤0.12 ms530 ms 2) Tr 300 r/min720015 000 r/min15 000 r/min4 msTr2 ms 300 r/min600 r/minTr50100 ms 3) Tt Tt/b: /20 ms10 MB/s10 KB21 ms100 KB30 ms1050%80 MB/s() 5.6.2 5-259I/OFCFS()55.3FCFSI/O 5-25 FCFS 2(SSTFShortest Seek Time First) 5-26SSTF95-255-26SSTFFCFSSSTFFCFS 5-26 SSTF 3(SCAN) 2) SCAN 5-27 SCAN 4(CSCAN) CSCAN2TT + SmaxTSmax()5-28CSCAN9 5-28 CSCAN 5NStepSCANFSCAN 1) NStepSCAN 2) FSCAN 5.6.3 1 2 3 1) 2) 3) LRULRULRU(LRU) 4 UNIX(update)SYNCSYNC30 s30 sMS-DOS: “”(write-through cache)MS-DOS 5.6.4 I/O 1(Read-ahead) 2 3 ()4 4 5.6.5 1 ……NN1NI/ON-15-29 5-29 2RAID (2) RAID 184 4 50% (3) RAID 3766/7RAID 3 (4) RAID 5/(Spiral)RAID 5I/O (5) RAID 6RAID 7RAIDRAID 6RAID 3RAID 5RAID 7RAID 6 3RAID (2) I/OI/ON-1(N)I/O (3) /RAID1/31/31/N50% rN b T CPU