{"id":116505,"date":"2024-06-12T18:05:44","date_gmt":"2024-06-12T16:05:44","guid":{"rendered":"https:\/\/prohoster.info\/blog\/novosti-interneta\/v-yadre-linux-poyavitsya-vozmozhnost-ispolzovaniya-ebpf-dlya-sozdaniya-planirovshhikov-zadach"},"modified":"2024-06-12T18:05:44","modified_gmt":"2024-06-12T16:05:44","slug":"v-yadre-linux-poyavitsya-vozmozhnost-ispolzovaniya-ebpf-dlya-sozdaniya-planirovshhikov-zadach","status":"publish","type":"post","link":"https:\/\/prohoster.info\/cs\/blog\/news\/v-yadre-linux-poyavitsya-vozmozhnost-ispolzovaniya-ebpf-dlya-sozdaniya-planirovshhikov-zadach","title":{"rendered":"V j\u00e1d\u0159e Linuxu se objev\u00ed mo\u017enost vyu\u017eit\u00ed eBPF pro vytv\u00e1\u0159en\u00ed pl\u00e1nova\u010d\u016f \u00faloh","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"
Linus Torvalds vyj\u00e1d\u0159il ochotu za\u0159adit do j\u00e1dra Linux 6.11, jeho\u017e vyd\u00e1n\u00ed se o\u010dek\u00e1v\u00e1 na konci z\u00e1\u0159\u00ed, patche implementuj\u00edc\u00ed mechanismus «sched_ext» (SCX), kter\u00fd umo\u017e\u0148uje vyu\u017e\u00edvat eBPF pro vytv\u00e1\u0159en\u00ed pl\u00e1nova\u010d\u016f CPU pokr\u00fdvaj\u00edc\u00edch t\u00e9m\u011b\u0159 v\u0161echny aspekty pl\u00e1nov\u00e1n\u00ed prov\u00e1d\u011bn\u00ed \u00faloh a p\u0159id\u011blov\u00e1n\u00ed zdroj\u016f CPU. Takov\u00e9 pl\u00e1nova\u010de je mo\u017en\u00e9 dynamicky na\u010d\u00edtat a prov\u00e1d\u011bt uvnit\u0159 j\u00e1dra Linux ve virtu\u00e1ln\u00ed ma\u0161in\u011b eBPF, kde je d\u00edky pou\u017eit\u00ed JIT kompilace bajtk\u00f3d p\u0159ekl\u00e1d\u00e1n na strojov\u00e9 pokyny a vykon\u00e1v\u00e1 se s v\u00fdkonem zkompilovan\u00e9ho k\u00f3du.<\/p>\n
Navrhovan\u00e9 patche implementuj\u00ed novou t\u0159\u00eddu pl\u00e1nov\u00e1n\u00ed SCHED_EXT, pro kterou je stanovena priorita vol\u00e1n\u00ed j\u00e1drem mezi t\u0159\u00eddami SCHED_IDLE a SCHED_NORMAL, co\u017e br\u00e1n\u00ed v BPF obsluh\u00e1ch, p\u0159ipojen\u00fdch k SCHED_EXT, ovlivnit \u00falohy ji\u017e p\u0159ipojen\u00e9 k standardn\u00edmu pl\u00e1nova\u010di \u00faloh (SCHED_NORMAL), ale umo\u017e\u0148uje p\u0159ipojen\u00ed jednotliv\u00fdch \u00faloh k SCHED_EXT nebo p\u0159esun v\u0161ech proces\u016f s ni\u017e\u0161\u00ed prioritou, kter\u00e9 nejsou v re\u00e1ln\u00e9m \u010dase, k jeho zpracov\u00e1n\u00ed. Pokud k SCHED_EXT nejsou p\u0159ipojeny BPF obsluhy, v\u0161echny procesy p\u0159esunut\u00e9 do t\u0159\u00eddy SCHED_EXT budou zpracov\u00e1v\u00e1ny pomoc\u00ed pl\u00e1nova\u010de SCHED_NORMAL. Pr\u00e1ce BPF obsluh se skl\u00e1d\u00e1 z anal\u00fdzy front \u00faloh \u010dekaj\u00edc\u00edch na vykon\u00e1n\u00ed na CPU (jedna glob\u00e1ln\u00ed fronta a jedna fronta na ka\u017ed\u00e9 j\u00e1dro CPU) a v\u00fdb\u011bru \u00falohy, kter\u00e9 by m\u011bly b\u00fdt poskytnuty CPU zdroje p\u0159i uvoln\u011bn\u00ed fronty j\u00e1dra CPU.<\/p>\n
Mechanismus sched_ext zjednodu\u0161uje vytv\u00e1\u0159en\u00ed specifick\u00fdch pl\u00e1nova\u010d\u016f pro ur\u010dit\u00e9 \u00falohy, umo\u017e\u0148uje experimentovat s r\u016fzn\u00fdmi technikami a strategiemi pl\u00e1nov\u00e1n\u00ed a tak\u00e9 umo\u017e\u0148uje rychle vytv\u00e1\u0159et pracovn\u00ed prototypy a vym\u011b\u0148ovat pl\u00e1nova\u010de on-the-fly v pracovn\u00edch infrastruktur\u00e1ch. Nap\u0159\u00edklad pomoc\u00ed sched_ext lze vytvo\u0159it pl\u00e1nova\u010d, kter\u00fd zohled\u0148uje specifika ur\u010dit\u00e9 aplikace a dynamicky m\u011bn\u00ed strategii pl\u00e1nov\u00e1n\u00ed jej\u00edho vykon\u00e1v\u00e1n\u00ed v z\u00e1vislosti na stavu syst\u00e9mu a dal\u0161\u00edch faktorech. <\/p>\n
V sou\u010dasnosti se ji\u017e vyv\u00edj\u00ed asi des\u00edtka pl\u00e1nova\u010d\u016f zalo\u017een\u00fdch na sched_ext, jejich\u017e logika pl\u00e1nov\u00e1n\u00ed \u00faloh je definov\u00e1na v prostor u\u017eivatele a na\u010d\u00edt\u00e1na do j\u00e1dra ve form\u011b BPF program\u016f:<\/p>\n
\n
scx_layered — hybridn\u00ed pl\u00e1nova\u010d \u00faloh, kter\u00fd d\u011bl\u00ed \u00falohy do vrstev, p\u0159i\u010dem\u017e na ka\u017edou vrstvu se vztahuje vlastn\u00ed strategie pl\u00e1nov\u00e1n\u00ed. Nap\u0159\u00edklad scx_layered umo\u017e\u0148uje vy\u010dlenit do samostatn\u00e9 vrstvy n\u011bkter\u00e9 \u00falohy, pro kter\u00e9 budou poskytnuty ur\u010dit\u00e9 garantovan\u00e9 zdroje CPU, nebo zv\u00fd\u0161it prioritu jednotliv\u00fdch aplikac\u00ed. Pl\u00e1nova\u010d vyv\u00edj\u00ed spole\u010dnost Meta. Logika generace BPF pracuj\u00edc\u00ed v u\u017eivatelsk\u00e9m prostoru je naps\u00e1na v jazyce Rust.\n
scx_rustland — pl\u00e1nova\u010d optimalizovan\u00fd pro zvy\u0161ov\u00e1n\u00ed priorita interaktivn\u00edch \u00faloh na pozad\u00ed \u00faloh intenzivn\u011b zat\u011b\u017euj\u00edc\u00edch CPU. Nap\u0159\u00edklad v testu spu\u0161t\u011bn\u00ed hern\u00ed aplikace Terraria sou\u010dasn\u011b se sestaven\u00edm j\u00e1dra pl\u00e1nova\u010d scx_rustland umo\u017enil dos\u00e1hnout ve h\u0159e vy\u0161\u0161\u00edho FPS ne\u017e p\u0159i pou\u017e\u00edv\u00e1n\u00ed standardn\u00edho pl\u00e1nova\u010de EEVDF. Projekt vyv\u00edj\u00ed zam\u011bstnanec spole\u010dnosti Canonical. Logika generace BPF pracuj\u00edc\u00ed v u\u017eivatelsk\u00e9m prostoru je naps\u00e1na v jazyce Rust.\n
scx_lavd — implementace algoritmu pl\u00e1nov\u00e1n\u00ed \u00faloh LAVD (Latency-criticality Aware Virtual Deadline), kter\u00fd zohled\u0148uje d\u016fle\u017eitost sni\u017eov\u00e1n\u00ed latenc\u00ed pro konkr\u00e9tn\u00ed \u00falohy a vyu\u017e\u00edv\u00e1 informace o pr\u016fb\u011bhu vykon\u00e1v\u00e1n\u00ed proces\u016f p\u0159i rozhodov\u00e1n\u00ed o p\u0159id\u011blov\u00e1n\u00ed zdroj\u016f CPU. Pl\u00e1nova\u010d vyv\u00edjej\u00ed spole\u010dnosti Igalia a Valve za \u00fa\u010delem sn\u00ed\u017een\u00ed latenc\u00ed v po\u010d\u00edta\u010dov\u00fdch hr\u00e1ch a interaktivn\u00edch \u00faloh\u00e1ch. Logika generace BPF pracuj\u00edc\u00ed v u\u017eivatelsk\u00e9m prostoru je naps\u00e1na v jazyce Rust.\n
scx_rusty, scx_rlfifo, scx_mitosis — p\u0159\u00edklady pl\u00e1nova\u010d\u016f s komponenty v u\u017eivatelsk\u00e9m prostoru napsan\u00fdmi v jazyce Rust, kter\u00e9 implementuj\u00ed vyv\u00e1\u017een\u00ed mezi skupinami \u00faloh v z\u00e1vislosti na z\u00e1t\u011b\u017ei, nejjednodu\u0161\u0161\u00ed FIFO pl\u00e1nova\u010d a pl\u00e1nova\u010d pro v\u00e1z\u00e1n\u00ed skupin \u00faloh na j\u00e1dra CPU.\n
scx_central, scx_flatcg, scx_nest, scx_pair, scx_qmap, scx_simple, scx_userland \u2014 p\u0159\u00edklady pl\u00e1nova\u010d\u016f s komponenty v u\u017eivatelsk\u00e9m prostoru v jazyce C, ilustruj\u00edc\u00ed r\u016fzn\u00e9 mo\u017enosti sched-ext.\n<\/ul>\n
P\u016fvodn\u011b byl mechanismus sched_ext navr\u017een k posouzen\u00ed v\u00fdvoj\u00e1\u0159i j\u00e1dra v roce 2022, po \u010dem\u017e bylo zve\u0159ejn\u011bno \u0161est verz\u00ed opravy. P\u0159esto\u017ee v z\u00e1kladn\u00edm j\u00e1dru nen\u00ed podpora, pro distribuce Ubuntu, Arch Linux, Fedora a NixOS je k dispozici mo\u017enost instalace sched_ext prost\u0159ednictv\u00edm dodate\u010dn\u00fdch bal\u00ed\u010dk\u016f. Spole\u010dnost Canonical zva\u017euje zahrnut\u00ed komponent\u016f sched-ext do Ubuntu 24.10 a spole\u010dnost Valve pracuje na integraci sched_ext do Steam Deck. Ve spole\u010dnosti Meta je pl\u00e1nova\u010d zalo\u017een\u00fd na sched_ext ji\u017e pou\u017e\u00edv\u00e1n v pracovn\u00ed infrastruktu\u0159e. <\/p>\n
Spole\u010dnost Google experimentuje s pou\u017eit\u00edm vlastn\u00edho r\u00e1mce ghOSt, kter\u00fd umo\u017e\u0148uje ovliv\u0148ovat rozhodnut\u00ed pl\u00e1nova\u010de \u00faloh pomoc\u00ed BPF program\u016f. V sou\u010dasn\u00e9 dob\u011b za\u010dalo \u00fasil\u00ed o portov\u00e1n\u00ed ghOSt na sched_ext. Google tak\u00e9 vyv\u00edj\u00ed port sched_ext pro ChromeOS s \u00famyslem jej vyu\u017e\u00edt k nasazen\u00ed hybridn\u00edho pl\u00e1nova\u010de scx_layered pro sn\u00ed\u017een\u00ed latenc\u00ed bez pou\u017eit\u00ed roz\u0161\u00ed\u0159en\u00ed pro provoz v re\u00e1ln\u00e9m \u010dase. Spole\u010dnost Oculus vyv\u00edj\u00ed port sched_ext pro Android. \n Zdroj: opennet.ru<\/a> <\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"