Preview:
DESCRIPTION
第五章 设 备 管 理. 5.1 I/O 系统 5.2 I/O 控制方式 5.3 缓冲管理 5.4 I/O 软件 5.5 设备分配 5.6 磁盘存储器的管理. 5.1 I/O 系统. 5.1.1 I/O 设备 1 . I/O 设备的类型 I/O 设备的类型繁多,从 OS 观点看,其重要的性能指标有 : 设备使用特性、数据传输速率、数据的传输单位、设备共享属性等。因而可从不同角度对它们进行分类。. 1) 按设备的使用特性分类 - PowerPoint PPT Presentation
Citation preview
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