????1.1 Linux????????
??????????????????????????????????Ч??????????????????????????Ч?????С?
????Linux??????????UNIX????????????????????????????ж???????????????????????????л????????????????????
??????????У??????????Linux????????????????????????????????????Linux?????δ????????????????????
????1.1.1 ????????
??????????????????????????????????????????y??????Linux????????????κ?????????????????
??????????????Linux???????е???????task_struct????????y????????????????????????????????????????н??????е?????????????????????????????????????????????????y???????????????????????к?????????????????????1-2????????????????????????


?????1-2 task_struct????

????1.1.2 ?????????????
?????????????????????????????紴???????С??????????????Щ??λ????????????????????????Ρ?????????????????????????????????????????


?????1-3????????????????????

????????????????????μ????????????????????????????? ???fork()?????á???fork()????????????????????′?????????????????????????????????μ????id?????????????????????????????????С?????????????????????????б???????????????????????????
????exec()??????????μ?????????????????????????????????д??????μ??????????????????????????????????￡?????????μ?????????????????
??????????????????д????????????????????????????????????????????????????????????????????????????????????????????????????????????Ч????μ?????????????????????????????????
????????????????????????????????exit()???????????exit()?????????????????????????????????????丸??????????????????????????????????????????page 7??“Zombie processes”????
??????????????????????丸??????????????????wait()???????????????????????????????????????????????????????????????????????
????1.1.3 ???
??????????????????????????????????е???????????????????е????????????????С?????????????????????????????楨???????????????????????????????????????????????????????????????Light Weight Process??LWP???????????????????????????????????????????????????????????????????????л????????????????Ρ?
????????????????????????????????????????????????????????????????????????????棬???????????????????????????????????????????????????


????
?1-4 ????????

???????????Linux????У???????UNIX????????????????POSIX?????????Linux?????????м?????????????????????????????
????LinuxThreads
????LinuxThreads???Linux???2.0?????????????????????LinuxThreads???Щ??????????POSIX?????Native POSIX Thread Library??NPTL?????????LinuxThreads??LinuxThreads???????Linux??????а??н?????????
????Native POSIX Thread Libary??NPTL??
????NPTL??????????????????NPTL??POSIX???????????Linux???2.6????????????磬?μ?clone()?????á???????????????????б?LinuxThreads?????????????????
????NPTL??LinuxThreads???Щ????????????????LinuxThreads?????????????NPTL????й?????
????Next Generation POSIX Thread??NGPT??
????NGPT?????IBM??????POSIX????????????????β?????δ?????п????????
???????LD_ASSUME_KERNEL?????????????????????????????????????
????1.1.4 ???????????nice?
????????????????????????????????????????????????????????????CPU?????????????и??????????????????и?????????????????????
????????????????????????????????????????????????????????????????????????????y????nice?????侲?????????????и????????????????????и???????????????????????????ж??????
????Linux????19?????????????-20?????????????nice????????0????????nice??????????????????????????????????root??????????su??????root?????С?
????1.1.5 ???????л?
????????????й????У??????????????????????????????????????????С???????е??????????????е??????????????????????л???????????н????????????????棬???????????н??????????????????????????С??????????????????????????????????????????????л?????????????л???????????????л??????????????????????ζ???????????????????棬??μ?????????????????????????????
?????1-5 ????????????л???ι?????


?????1-5 ???????л?

????1.1.6 ?ж????
?????ж???????????????????????ж??????I/O?豸??????????????????????????????????????????????????ж????????????????????????磬???????????????????????????????ж???????У???????????????ж?????????Щ?豸??????????????????????????????????ж??????????????????л??????????????μ??ж????????????ζ???ж??????????????л????????????ж??????????????????
??????Linux??????У?????????????ж????ж???????????????豸???????????I/O?ж?????????????ж???????ж??????ж???????ж????????????????????TCP/IP??????SCSIЭ??????????????????/proc/interrupts????в???ж??????????
?????????????????У??ж????????????????????ж?????????????????????????????????????????????4.4.2??“CPU???ж?????????”??
????1.1.7 ??????
?????????????????????????????????????????????
??????????????????????????????Щ??????????￡?
????TASK_RUNNING
??????????￡????????????CPU?????л???????е?????У????ж??У???
????TASK_STOPPED
??????????μ??????Щ??????SIGINT??SIGSTOP???????????????????????????????У?????SIGCONT??
????TASK_INTERRUPTIBLE
??????????￡??????????????????Щ????????????????????????TASK_INTERRUPTIBLE???????????????????????????????????ж??????????????TASK_INTERRUPTIBLE????????????????????????????ж??
????TASK_UNINTERRUPTIBLE
??????TASK_INTERRUPTIBLE??????????????????TASK_UNINTERRUPTIBLE????????ж??????TASK_UNINTERRUPTIBLE??????????????????????κβ????????TASK_UNINTERRUPTIBLE?????????????????????I/O??????