
brain phack schedular

brain phak schedular (bii. eff. ess.) haah eka prakriya schedular aahe joou august 2009 madhye linux karnalsathi purnapane nyayya schedular (see. eff. ess.) aanee oo. (1) schedularla paryay mhanoon tayar karnyat aala aahe. bii. eff. ess. heey anubhavi curnell programmer conn kolivas yanni tayar kele hote.
itar schedularchya tulanet bii. eff. ess. chaa uddesh schedularla eka sopa algoridam pradan karane haah aahe, jyala vishisht prakarchya sanganakeey kamachya bharala anuroop kamgiri karnyasathi huristics kinwa tuning parameterschya samayojanchi aavashyakta nahee. kolivasne thampane sangitale qee heey tune karnyayogya mapdand sarasari vaparkartyasathi samajoon ghene katheen hote, visheshtah ekmekanshi anek mapdandanchya parasparsanvadachya drushtine, aanee assa dawa keela qee asha tuning mapdandanchya vaparamule sahasa vishisht lakshyit prakarchya gananet sudharit kamgiri houu shakate, samanya babatit white kamgirichi kimmat. 16 korpeksha qamee asalelya linux desktop sangankanvar bii. eff. ess. neey pratisadatmakata sudharalyache nondavale gele aahe.
tyachya parichayanantar lagechach, naveen velapatrakartyane linux samudayamadhye "slashdot" varr disana mathalyanchi nirmiti kelee, aanee "linux masika" aanee "linux pro masika" madheel punravloknansah. sudharit kamgiri aanee pratisadatmakatebaddal vividh punaravalokne aalee asali taree, coone kolivasacha bii. eff. ess. laa mukhya reshechya karnalmadhye samakalit karnyacha hetu navhata.
saiddhantik rachana aanee karyakshamta.
2009 madhye, bii. eff. ess. sadar karnyat aale aanee tyanni moolatah duheri jodaleli yadee deta rachana vaparali hotee, parantu deta rachana rangasarkhi manali jaate. karya samavisht karane aahe. pudhil karya karyanvit karnyasathi karya shodhane hii sarvat white sthitee aahe. tee eka jaagtik dhavanyachi rang vaparte jee serve see. pii. yuu. vapartat. uchch velapatrak pradhanyakram asaleli kaame pratham amalat aanali jaatat. vastavik aanee samkalik pradhanya varg vagalata serve dhorananmadhye aabhasi antim mudatichya sutravar aadharit kaame aurder (kinwa vitarit) kelee jaatat aanee nivadali jaatat.
amalbajavaniche vartan heey ajunahi goal-robbin schedularche bharit bhinnata aahe, visheshtah jevha isochronus dhoranachya khalee kamanna samaan pradhanya asate. vaparkartyane vajavata yenyajoga goal robincha kalavadhi (velecha tukada) purvanirdharitapane 6 milisekandancha asato, joou manavanna shodhata yenyajoga kiman gadgada mhanoon nivadala gela hota. kolivasne assa dawa keela qee 6 mschya khalee kahihi arthaheen aahe aanee raund robbin timelissathi 300 mspeksha jaast kahihi thruputchya babatit nirathak aahe. heey mahattvache tune karnyayogya, throput aanee vilambata yanchyatil vinimay mhanoon raund robbin schedular tayar karoo shakate. realtime phipho vagalata serve kamanna ekach velecha tukada midato, jyamadhye anant velecha tukada asalyache manale jaate.
tyachya aar. dii. ess. ell. velapatrakat vaparlya gelelya prati see. pii. yuu. sathee bahu-rancue (raund robbin) pradhanya shrenipeksha duppat jodalelya yadichya mono-rancuseh jaanyache kaaran, anek see. pii. yuu. paristhitimadhye nishpakshata sulabh karnyasathi aanee bahu-rancue paristhititil pratyek rankyula tyachya swatachya vilambata aanee [karya] nishpakshata rakhavi lagnari jatilata door karnyasathi, kolivasne spasht kele. tyane dawa keela qee tyachya nantarchya muxchya punaravruttimadhye bii. eff. ess. saha nirdharak vilambanchi hummy denyat aalee hotee. see. pii. yuu. vadhavane aanee amalbajavanichya shodhasathi pudhil karyachya varchya bhagasah sambhavya lock condustration samasya (task node deta badalane, kadhoon takane, nirmitishi sambandhit) dekhil tyanni olakhali. mooks yanni tyaa samasya sodavanyacha prayatna keela.
tyanantar kolivasne 2016 madhye bii. eff. ess. chya v0.480 prakashanatil rachana vagalanyachya yadeet badalali. yaveli yamule velapatrakachi karyakshamta badalali. tyanni karya samavisht karane, karya shodhane;, saha, karya kadhoon taknyasathi nondavale.
aabhasi mudat.
aabhasi antim mudatiche sootra mhanje bhavishyatil antim mudatichi vel, jee sadhyachya velenusar (niphi units kinwa nanosecond jiffies, antargat curnell time countermadhye) changlya patalichya offsetvar aadharit scale keleli goal robbin timesleys aahe. aabhasi mudat keval aurder suchavate parantu ekhade karya bhavishyatil niyojit velenusarach chalel yachee hummy dett nahee.
pratham eka prathamik gunottar shodh sarani tayar kelee jaate. heey punaravrutti kramavar aadharit aahe. pratyek changlya patalivar 10 takke vaadh hote. heey graph kelele asalyas teey parabolic namunyache anusaran karate aanee nistej karye domain mhanoon 0 teey 39 (sarvoch teey sarvat qamee changlya pradhanyashi sambandhit) aanee shreni mhanoon 128 teey 5089 paryant halanare varg karya mhanoon vitarit kelee jaatat. halnara bhag aabhasi antim mudatichya sutratil chalmadhun yeto jyache sanket kolivasne dile aahet.
karyache chhan-teey-nirdeshank mapping karya chhan-20 pasoon mapp kele aahe.. 19 teey nirdeshank 0.. 39 haah prayo resho lookup tablemadhye input mhanoon vaparla jaeel. heey mapping function heey macrow inn schedude aahe.karnalchya shirshakat etch. antargat curnell amalbajavani 100 aanee 140 sthir pradhanyachya shrenisah kinchit bhinn aahe parantu vaparkarte teey-20 mhanoon pahatil.. 19 chhan.
aabhasi mudat yaa achook sutravar aadharit aaheh
paryayi,
chhanche karya mhanoon yu64 purnank nanosecondanmadhye aabhasi mudat kuthe aahe aanee nifijmadhye sadhyachi vel jee aahe, anukramanikeche karya mhanoon prayo resho table lookup aahe, heey karyache chhan-teey-nirdeshank mapping karya aahe, milisekandanmadhye goal robbin timeslice aahe, nanosecondanchya drushtine 1 milisekandancha sthirank aahe, kaaran formula _ 1 chya rupantaran ghatakacha andaje vilamb qamee karato parantu kolivas andaje tyaa pramanasah bases 2 sthirank vaparato. aabhasi mudat purvi nakaratmak chhan mulyanshi sambandhit aahe yacha arth lahan moolye. mothya moolye darshavtat qee aabhasi mudat nantar sakaratmak chhan mulyanshi sambandhit mage dhakalali jaate. jevha jevha kalmaryada sampate tevha teey heey sootra vaparte.
aadhar 2 madheel 128 heey aadhar 10 madheel 100 shhee aanee bahudha 'chhadm 100' shhee sambandhit aahe. bases 2 madheel 115 bases 10 madheel 90 shhee sambandhit aahe. kolivas "phasta shifts" sathee 128 vaparato, kaaran divisionmadhye rait shift bases 2 aahe.
velapatrak dhorane.
see. pii. yuu. karye kitee vaparu shakatat heey nirdharit karnyasathi bii. eff. ess. velapatrak dhorane vaparte. bii. eff. ess. 4 velapatrak starancha (jyanna velapatrak dhorane kinwa velapatrak varg mhanatat) vapar karate, jeey sarvottam teey sarvat white asha kramvarit dile jaatat, jeey shirshasthani asalelya karyanchi nivad kashee kelee jaate aanee pratham tyanchi amalbajavani kashee kelee jaate heey tharavatat.
pratyek karyache eka vishesh moolya asate jyala priya mhanatat. v0.462 aavruttimadhye (-keey. 4 curnell patchsetmadhye vaparale jaate), ekoon 103 "pradhanya ranga" (urf prio) kinwa parvanagi moolye aahet jee tee gheu shakatat. konatihi vastavik vishesh mahitee rachana pradhanyachi rang mhanoon vaparali gelee nahee parantu keval duppat jodaleli yadich vaparali gelee. qamee prayo moolya mhanje teey adhik mahatvache aahe aanee pratham karyanvit hote.
vastavik veleche dhoran.
vastavik veleche dhoran vastavik velechya kamansathi tayar kele gele hote. heey dhoran soochit karate qee chaloo asalelya karyanmadhye vyatyay aanala jaau shakat nahee (i.eae. purvaniyojit) qamee pradhanya asalelya karyadvare kinwa qamee pradhanya dhoran starandvare. schedularne realtime dhoranantargat vicharat ghetalele pradhanya varg mhanje schedue _ rr aanee schedue _ phipho asey chinhankit kelele aahet. schedular realtime raund robbin (schedue _ rr) aanee realtime phipho (schedue _ phipho) yanna vegalya paddhatine hatalato.
yaa aarakhadyane pahilya 100 sthir pradhanya ranganchi mandani kelee. 
amalbajavanisathi nivadalele karya heey 100 ranganpaiki sarvat qamee mulyachya prayochya karya upalabdhata aanee phipho velapatrakavar aadharit aahe.
kontyanvar, prakriyeche pradhanya samanya dhoranat qamee kele jaeel.
visheshadhikar nasalelya vaparavar (i.eae. schedularcha gair-mool vaparkarta) jyala real time policy klassathi vinanti karoon coll keela jaato, schedular karyala isochronus dhoranat utarvel.
samkalik dhoran.
isochronus dhoran heey mool nasalelya vaparkartyansathi jawalpas vastavik velechya kamgirisathi tayar kele gele hote.
rachana 1 pradhanya rang tayar karate jee purvanirdharitapane chhadm-vastavik vel karye mhanoon chalate, parantu vastavik velechi degree mhanoon tune kelee jaau shakate.
dhoranatil vartan ekhadya karyala samanya dhoranat utaravu shakate jevha teey online cpu aanee timer resolution adhik 1 tikchya sankhyeparyant mojalya gelelya 5 sekandanchya tune karnyayogya sansadhan hatalani takkevaripeksha (purvanirdharitapane 70 takke) jaast asate. bahu-rancue designmule sootra mukesmadhye badalale gele. achook sutre ashee aaheth
sambhru undaranchi ekoon sankhya kuthe aahe, timer frequency aahe, online cpuchi sankhya aahe, hii dashanshat navhe tarr sampoorn sankhya mhanoon tune karnyayogya sansadhan hatalanichi takkewari aahe. timerchi varanvarta purvanirdharitapane 250 varr seet kelee jaate aanee karnalmadhye sampadan karnyayogya asate, parantu sahasa sarvharsathi 100 heartz aanee parasparsanvadi desktopsathi 1000 hertzwer tune kelee jaate. 250 heey santulit moolya aahe. 100 banavaleli kaame vastavik velepramane vagatat aanee 0 neey tee chhadm-vastavik vel banavali nahee aanee madhalya konatyahi goshtila chhadm-vastavik vel asey mhatale jaate.
jyaa karyasathi sarvat aadhi aabhasi mudat hotee teey karya amalbajavanisathi nivadle gele hote, parantu jevha anek isochronus karye astitvat asatat, tevha teey goal robbin mhanoon velapatrakbaddha karatat jyamule karye ekapathopath eka suyogya goal robbin moolya (purvanirdharit mhanoon 6 mss) chalvu shakatat.
samkalik dhoranache heey vartan keval bii. eff. ess. aanee emm. yuu. kyu. ess. ess. sathee adviteey aahe aanee itar see. pii. yuu. schedularmadhye lagoo kele jaau shakat nahee.
samanya dhoran.
samanya dhoran niyamit vaparasathi tayar kele gele hote aanee teey purvanirdharit dhoran aahe. navyane tayar keleli kaame samanyatah samanya mhanoon chinhankit kelee jaatat. 
eka pradhanya rang tayar keleli rachana aanee karye lavkar aabhasi mudatichya aadhare pratham amalat aananyasathi nivadali jaatat.
nishkriy pradhanya dhoran.
nishkriy pradhanya heey vitarit karyakram aanee transcodersarkhya parshvabhoomi prakriyansathi tayar kele gele hote jenekarun agrabhagachya prakriya kinwa yaa velapatrak dhoranachya vareel prakriya akhanditpane chaloo shaktil.
1 pradhanya rang aanee karye nishchit kelelya aarakhadyala anishchit sansadhananchi pakad talhanyasathi aapoaap samanya dhoranat badhati dilee jaau shakate.
samaan pradhanya dhoranat rahana itarambarobar nishkriy pradhanya asalele pudhil karyanvit karya lavkar aabhasi mudatiparyant nivadle jaate.
purvagrah.
jevha uchch pradhanya dhoranasah navyane tayar kelele karya (mhanje.eae. uchch prayo) chee sadhya suru asalelya karyapeksha aadhichi aabhasi mudat asate-jee kalbahya kelee jaeel aanee ranget mage thewali jaeel. descheduled mhanje tyachi aabhasi mudat adyayavat kelee aahe. jevha kamacha serve vel vaya jaato tevha tyacha vel jastit jaast goal robinchya pramanat punha bharala jaato. jarr schedularla heey kaam sarvat lavkar aabhasi mudatisah uchch prayovar aadhalale, tarr serve tarkik cpu (hyperthreaded coor/smt threads) vyast asateel tarach teey sadhya suru asalelya qamee mahattvachya karyachya jaagi karyanvit hoil. jarr naan vaparlele tarkik cpu asel tarr schedular shakya titka kaal purvpraptila vilamb karel.
jarr ekhade kaam nishkriy pradhanya dhoran mhanoon chinhankit kele asel, tarr teey itar nishkriy dhoran chinhankit kelelya kamanna dekhil purvaniyojit karoo shakat nahee, parantu tyaeivaji sahkari bahukarya vapara.
karya niyojan, anek coor.
jevha anusuchakala naun-unicor pranalivar jaage honyache karya sapadel, tevha tyala karya konatya tarkik see. pii. yuu. varr chalvayache heey tharvave lagel. schedular bahutek nishkriy hyperthreaded coor (kinwa nishkriy ess. emm. tii. dhage) laa pradhanya deto, pratham tyach see. pii. yuu. varr jyavar karya karyanvit kele jaate, nantar multicore see. pii. yuu. chaa dusra nishkriy coor, nantar tyach neuma nodavareel itar see. pii. yuu., nantar serve vyast hyperthreaded coor/ess. emm. tii. dhage/tarkik see. pii. yuu. ekach neuma nodavar purvavat kele jaatat, nantar dusra (durastha) neuma node aanee pradhanya yadeet sthan deela jaato. heey vishesh scan karya sthalantarit karnyachya parinami vilambit overhead qamee karnyasathi astitvat aahe.
purvprapti kram vareel parichheda sarkhach aahe. preamption kram haah hyperthreaded coor/ess. emm. tii. units aahe, joou pratham tyach multicorver, nantar multicoremadhil dusra coor, nantar tyach neuma nodavareel dusra see. pii. yuu. aahe. jevha teey dusya durastha neuma nodmadhye purvaniyojit karnyasathi ekhadya karyasathi scan karate, tevha yantratil serve tarkik cpu (hyperthreaded coor/smt dhagyansah) serve vyast aahet asey gruheet dharoon, qamee teey samaan prayo kinwa nantarchya aabhasi mudatisah konatehi vyast dhage heey purvaniyojit asate. purvaniyojit karnyasathi aanee uchch pradhanya dhoran asalelya karyasah tarkik cpu talhanyasathi, jeey teey purvaniyojit karoo shakat nahee, velapatrakartyala qamee kinwa kadachit samaan pradhanya dhoran karyasah (aavashyak asalyas nantarchya aabhasi mudatisah) yogya karyasathi scan karave lagel. durastha nishkriy sankhya ekkasathi scanning karnyapeksha sthanik purvpraptichi shreni jaast asate.
jevha curnell madhyasth cpu frequency scaling (urf cpu frequency governor) chya parinami cpucha veg qamee hoto tevha ekhade kaam anaichhikpane purvavat kele jaate, tevha vastavik vel dhoran mhanoon chinhankit kelele vagalata karya vishesharitya 'chikat' chinhankit kele jaate. chinhankit chikatpana heey soochit karato qee karyat ajunahi naan vaparlela vel aahe aanee karya tyach see. pii. yuu. paryant maryadit aahe. jevha jevha see. pii. yuu. scaling governorne qamee vegane see. pii. yuu. surr kele asel tevha heey kaam chikat chinhankit kele jaeel. nishkriy chikat kelele karya ektar yogayogane purn jee. etch. zed. vegane karyanvit karnyasathi parat yeil kinwa karya chalavalelya samaan see. pii. yuu. nasalelya sarvottam nishkriy see. pii. yuu. varr karyanvit karnyasathi punarnirdharit kele jaeel. heey kaam itar thikani sthalantarit karane isht nahee, parantu teey kaam dusya see. pii. yuu. kinwa neuma nodavar sthalantarit karnyasathi overheadmule vadhalelya vilambamule teey nishkriy karane isht aahe. heey chikat vaishishtya kolivaschya patchset 4.8-ck1 shhee sambandhit bfschya (v0.512) shevatchya punaravruttimadhye kadhoon taknyat aale aanee teey mukesmadhye astitvat navhate.
velapatrak sadhan.
visheshadhikarprapt vaparkarta schedudal programs prakriyeche pradhanya dhoran badaloo shakato kinwa teey programdvarech kele jaate. pradhanya varg code staravar keval rutsathi upalabdh asalelya sed _ setscheduler sarkhya syscall saha hatalala jaau shakato, joou sedtool vaparato.
manke.
eka samkalin abhyasat, lekhakane linux curnell v3.6.2 aanee anek kamgiri-aadharit antim bindu vaparoon bfschi tulana cfsshe kelee. yaa abhyasacha uddesh vanilla linux karnalmadhil purnapane yogya schedularche (see. eff. ess.) aanee see. keey. 1 patchsets patch kelelya sambandhit karnalmadhil bii. eff. ess. chey moolyankan karane haah hota. farak astitvat aahet qaa aanee kamgirivar aadharit metricks vaparoon teey kitee pramanat mojatat heey pahanyasathi saat vegvegalya yantrancha vapar karnyat aala. tarkik cpuchi sankhya 1 teey 16 paryant hotee. heey antim-bindu bfschya prathamik rachana uddishtanmadhye kadhihi ghatak navhate. parinam utsahavardhak hote.
bii. eff. ess. saha see. keey. 1 patch sanchasah patch kelelya karnalani chachani kelelya jawaljawal serve kamgiri-aadharit mapdandanvar see. eff. ess. vaparoon vanilla karnala mage takale. mothya chachani sanchasah pudhil abhyas keela jaau shakato, parantu moolyankan kelelya 7 sanganakanchya chhotya chachani sanchavar aadharit, prakriya ranganmadhil hii vaadh, karyakshamta/veg, ekunach, see. pii. yuu. prakarapasoon (mono, dual, kwad, hyperthreaded ii.) swatantra aahet.), cpu architecture (32-biit aanee 64-biit) aanee cpu multiplicity (mono kinwa dual saket).
shivay, samanya workstation aanee laptopche pratinidhitva karananya intell coor 2 jodee aanee coor aay 7 sarkhya anek "aadhunik" cpuver, bfsne serve nikashanvar vanilla karnalmadhil cfspeksha satatyane kamgiri kelee. karyakshamta aanee veg qamee teey madhyam hota.
dattak.
bii. eff. ess. haah khaleel desktop linux vitaranansathi purvanirdharit velapatrak aaheh
yavyatirikt, googalchya android vikas bhandarachya prayogik shakhet bii. eff. ess. jodanyat aale aahe. andh chachanimadhye sudharit vaparkarta anubhav naan disalyane tyacha samavesh froyo prakashanamadhye karnyat aala nahee.
mooks.
bii. eff. ess. laa muxchya bajoone nivrutt karnyat aale aahe, jyala aupcharikpane multiple kyu skiplist schedular mhanoon olakhale jaate, jee tyach sankalpanechi punarlikhit amalbajavani aahe. prathamik lekhakane august 2021 chya akheris muxveril kaam sodoon dile.
saiddhantik rachana aanee karyakshamta.
mukes hii dvidishatmak sthir shrenibaddha 8 stariy vagalanyachi yadee vaparte aanee kaame sthir pradhanya [ranga] (velapatrak dhoranacha sandarbh) aanee aabhasi mudtinusar kramvarit dilee jaatat. cashelinemadhil arreymadhye basnyasathi 8 nivadanyat aale. karya kadhoon taknyas gatee denyasathi duppat jodaleli deta rachana rachana nivadali gelee. ekhade kaam kadhoon taknyasathi double skip lists fakt oo (1) aanee vilyam pagchya mool designchi sarvat white sthitee asate.
karya samavisht karane aahe. amalbajavani shodhanyache pudhil karya mhanje, see. pii. yuu. chee sankhya kuthe aahe. amalbajavanisathi pudhil karya prati rancue aahe, parantu velapatrakarta cpumadhye karya nishpakshata rakhanyasathi, vilamb kinwa santulan rakhanyasathi (see. pii. yuu. chaa vapar aanee cashey cohensey tyach sankhya nodavar jastit jaast karnyasathi jeey sankhya nodesmadhye pravesh karatat), mhanoon shevati itar pratyek runcuechy tapasani karato. tee hatalu shakanari jastit jaast karye mhanje prati see. pii. yuu. prati runcue 64 hazar karye aahet. heey kahee sanrachananmadhye anek task runcue vaparte, eka runcue prati see. pii. yuu., tarr tyache purvavarti bii. eff. ess. serve see. pii. yuu. sathee fakt eka task runcue vaparat hote.
vagalanyachya yadimadhye gradient mhanoon kaame asha prakare aurder kelee jaatat qee real time dhoran pradhanya pratham yete aanee nishkriy dhoran pradhanya shevati yete. samanya aanee nishkriy pradhanya dhoran ajunahi aabhasi mudtinusar kramvarit aanale jaate jeey chhan moolye vaparte. vastavik aanee samkalik dhoranatmak kaame changlya mulyankade durlaksh karoon phipho kramane chalavali jaatat. tyach killisah naveen kaame phipho kramane thewali jaatat mhanje naveen kaame yadichya shevati thewali jaatat (i.eae. sarvat varche node anulamb), aanee 0 vya staravaril kinwa samoril-khalchya bhagat asalelya karyanna varchya jawalchya aanee haid nodapasoon sarvat door asalelya karyanpurvi aadhi amalat aanale jaate. samavisht kelelya kramvarisathi vaparali jaanari killi ektar sthir pradhanya kinwa aabhasi mudat asate.
vaparkarta bahu-kormadhye runcuse samayik karane nivadu shakato kinwa prati tarkik cpu runcue thevu shakato. rankyujchi rachana samayik karnyacha andaj haah thruputchya vinimayasah vilamb qamee karane haah hota.
muxney sadar keleli eka naveen vaganuk mhanje, jevha veleche dastaivaj vaparale gele, tevha milisekandanpeksha qamee achukatesathi uchch resolution timercha vapar karane, parinami karyanche punarnirdharan karane.