U-Linus Benedict Torvalds ungunjiniyela wesoftware waseFinland-American, owaziwa ngokuqala nokugcina ukuthuthukiswa kwe-Linux kernel,
Ezinsukwini ezithile ezedlule U-Linus Torvalds wenza umbono wakhe waziwa ngokuqeda ukwesekwa for processor Architecture i486 ku-Linux kernel. Isakhiwo esidala kwaxoxwa ngaso ezinsukwini ezimbalwa ezedlule kuchungechunge olubheka ukuthi i-kernel ingaphatha kanjani kangcono uhlu lwakamuva lokusetshenziswa (LRU), indlela yokugcina umkhondo wamakhasi enkumbulo.
Ngesikhathi U-Torvalds uphenye ikhodi yabahlanganyeli, kubonakala sengathi sikhungathekile ngesidingo sokuhlanganisa izixazululo ezanele kuma-CPU amadala. Ngakho-ke, uphakamise ukuqeda ukusekelwa kwekhithi endala, okungase kube indlela elula yokulungisa izinkinga zenkumbulo.
“Sahlukana noxhaso lwe-i386 ngo-2012. Mhlawumbe sekuyisikhathi sokulahla i-i486 ngo-2022? ULinus Torvalds uthi
Sesivele senza (kuyavunywa ukuthi akulungile: ayiphephile nge-SMP, okungukuthi izosebenza kahle ngisho nalapho sibhekene nokufinyelela ngesikhathi esisodwa okuvela emiculweni eminingi yokubulawa, kodwa imishini ye-SMP Class 486 ayizange isekelwe nakuba yayikhona ngokobuchwepheshe)
Kufanele kukhunjulwe lokho uchungechunge lwe-i486 CPU lwakhululwa ngo-1989 futhi okwamanje kumbalwa kakhulu ukusatshalaliswa kweLinux okufana neGentoo, Slackware kanye ne-KNOPPIX kuyaqhubeka nokusekela lesi sakhiwo.
Ngokusho kukaTorvalds, izinkinga ezibangelwa ukusekela izakhiwo eziphelelwe yisikhathi ezisetshenziswa abantu abambalwa kungase kube lula ukuzixazulula ngokususa ukusekela kwazo. Ukuphathwa kwenkumbulo ye-LRU yamaphrosesa amadala nakho kungaba icala elinjalo.
Ngokweqiniso, anginandaba nokuthuthukisa izidingo eziyisisekelo okungenani zibe yi-M586TSC, ngishiye amanye alawo ma-clone "amanga e-Pentium" okuqala. Ngoba i-'rdtsc' cishe iyinkinga embi kakhulu kune-CMPXCHG8B.
Futhi yilokho konke kubilisa ku-cmpxchg8b, umyalo oqhathanisa bese ushintshanisa amabhayithi ayisishiyagalombili (noma amabhithi angu-64) olwazi kumemori yekhompyutha. Ilungu lohlu lwamakheli u-Peter Zijlstra uphakamise ukuthi i-Linux kufanele isekele kuphela amaphrosesa akwazi ukwenza lokhu, ishiye i-486-bit i32 ngemuva futhi okusho ukuthi ama-Linux kernels amasha azosebenza nge-hardware yeklasi ye-P5 noma entsha.
Umyalo we-cmpxchg8b umlandu wephutha le-'F00F' kusukela ku-Pentium yasekuqaleni, lapho i-CPU ethintekile ngaphandle kokunciphisa isistimu yokusebenza iyeke ukusebenza ize iqaliswe kabusha lapho iyalwa ukuba isebenzise umyalo.
Empeleni, angiqondi nhlobo ukuthi kungani izinhlamvu zamanje zisebenza ku-i486, njengoba kubukeka sengathi phuma_kuya_komsebenzisi_ukulungiselela -> i-arch_exit_to_user_mode_prepare, futhi igcina ngokuba nesitatimende esingenamibandela 'rdtsc'.
Ngicabanga ukuthi awukayiniki amandla.RANDOMIZE_KSTACK_OFFSET*? Ngamanye amazwi, imidiya yethu okungeyona eye-Pentium AYIKHOMELEKAYO FUTHI YEPHUKILE khona manje.
Ngokusho kwakhe, kuyangabazeka kakhulu ukuthi i-i486 hardware isasebenza. Akungabazeki ukuthi basekhona abantu abazimisele kangaka emhlabeni, abakholelwa ukuthi izinkinga eziwumphumela zinganqotshwa kalula, kodwa ngombono wokuthuthukiswa kwe-kernel, lesi sikhundla asifanele ngempela.
“Ngakho-ke angicabangi ukuthi i-hardware ye-i486-class isasebenza. Yebo, ngiqinisekile ukuthi kukhona (uMaciej uyisibonelo), kodwa ngokombono wokuthuthukiswa kwe-kernel, angicabangi ukuthi abalulekile ngempela. Ngesinye isikhathi, abantu baba nazo njengezingcezu zemnyuziyamu. Bangakwazi futhi ukuphatha ama-nuclei eminyuziyamu.
Kumele kushiwo ukuthi i-architecture I-i486 ikhishwe ngo-1989 futhi yathathelwa indawo yi-Intel's Pentium ngo-1993. I-Intel yalahla i-i486 ngo-2007 futhi namuhla isizindalwazi sayo esidumile semininingwane yomkhiqizo we-Ark ayiqukethe lutho ngomndeni womprosesa.
Labo abasasebenzisa amadivaysi kudala basula ukwenza lokho ngaphandle kokusekelwa, ngaphandle kokuba nethuba lokuthola ikhithi entsha noma ukuthi abathuthukisi be-software bacabange ngeplatifomu.
Ukuze uthole imininingwane eyengeziwe, i-Intel 80486 (i486, 486) iyi-microprocessor yomndeni we-x86, eyenziwe ngabakwa-Intel. Ikhishwe ngo-1989. Ngokwezakhiwo zeprosesa, i-80486 ifana kakhulu neyandulelayo, i-Intel 80386, ngokungezwa kwemiyalelo embalwa eyengeziwe. Ngakho-ke, i-architecture ye-CISC.
Ngokombono wesakhiwo esincane, kwakukhona intuthuko enkulu ngaleso sikhathi: imfundo ehlanganisiwe ehlanganisiwe nenqolobane yedatha, iyunithi yokucubungula yephoyinti elintantayo elihlanganisiwe (i-FPU), kanye nesixhumi esibonakalayo sebhasi esithuthukisiwe.
Ekugcineni ubalula for the abasebenzisi abanamasistimu anama-i486 processors bazokwazi ukusebenzisa izinguqulo ze-LTS ze-kernelezohlala iminyaka eminingi ezayo.
Ukusekelwa kwamamodeli amadala amaphrosesa namadivayisi kungase kususwe ku-Linux kernel ngenxa yezizathu ezihlukahlukene, njengokwenza lula nokuthuthukisa ikhodi, ukunciphisa inkimbinkimbi ye-kernel nokugcinwa, noma ukugxila kumadivayisi esimanjemanje nadumile. Ezinye izibonelo zamamodeli amadala angasuswa ekusekelweni kwe-Linux kernel zifaka:
Amaphrosesa amadala: njenge-Intel i386, i486, noma amanye amaphrosesa amadala we-AMD. Lawa maphrosesa madala kakhulu futhi awasekeli izici zakamuva ze-Linux kernel.
Imishini yakudala yama-peripheral: Okufana namadrayivu etheyiphu, ama-floppy drive, noma amanye amakhadi amadala omsindo noma evidiyo. Lawa madivayisi awavamile namuhla, ngakho-ke ukusekelwa kwawo kungase kuhoxiswe ukuze kuncishiswe ubunzima be-kernel.
Ubuchwepheshe obuphelelwe yisikhathi: njengosekelo lwephrothokholi yenethiwekhi ye-IPX, eyayivamise ukusetshenziswa kumanethiwekhi ekhompyutha emashumini eminyaka edlule. Njengoba ubuchwepheshe buthuthuka futhi bushintsha, ukusekela kobuchwepheshe obehlisiwe kungase kuhoxiswe ku-kernel.