Katswiri wa Google adakonza zoteteza mapulogalamu a mapurosesa ku ma LVI

Kale zidadziwika za chiwopsezo chatsopano pamapangidwe ongoyerekeza a ma processor a Intel, omwe amatchedwa. Load Value jekeseni (LVI). Intel ili ndi malingaliro ake pazowopsa za LVI ndi malingaliro ochepetsera. Njira yanu yodzitetezera ku zigawenga zoterezi analimbikitsa injiniya ku Google. Koma muyenera kulipira chitetezo pochepetsa magwiridwe antchito a purosesa ndi 7%.

Tidawona kale kuti kuopsa kwa LVI sikuli m'makina enieni omwe adapezeka ndi ochita kafukufuku, koma mu mfundo yomwe idawukira mbali ya LVI, yomwe idawonetsedwa koyamba. Chifukwa chake, njira yatsopano idatsegulidwa pazowopseza zomwe palibe amene adazikayikirapo kale (osachepera, izi sizinakambidwe pagulu). Chifukwa chake, phindu la chitukuko cha katswiri wa Google Zola Bridges lili mu mfundo yakuti chigamba chake chimachepetsa chiopsezo cha kuukiridwa kwatsopano kosadziwika kutengera mfundo ya LVI.

M'mbuyomu mu GNU Project Assembler (GNU Assembler) kusintha kwapangidwa komwe kumachepetsa chiopsezo cha chiwopsezo cha LVI. Zosintha izi zidaphatikizapo kuwonjezera chotchinga malangizo LFENCE, yomwe idakhazikitsa ndondomeko yokhazikika pakati pa zofikira zokumbukira zisanachitike komanso pambuyo pa chotchinga. Kuyesa chigamba pa imodzi mwama processor a Intel's Kaby Lake kunawonetsa kuchepa kwa magwiridwe antchito mpaka 22%.

Wopanga Google adakonza chigamba chake ndikuwonjezera malangizo a LFENCE ku LLVM compiler set, ndikutcha chitetezo SESES (Speculative Execution Side Effect Suppression). Njira yachitetezo yomwe adafuna imachepetsa ziwopsezo zonse za LVI ndi zina zofananira, mwachitsanzo, Specter V1/V4. Kukhazikitsa kwa SESES kumalola wopanga kuti awonjezere malangizo a LFENCE m'malo oyenera panthawi yopanga makina. Mwachitsanzo, alowetseni patsogolo pa malangizo aliwonse owerengera kuchokera pamtima kapena kulemba pamtima.

Malangizo a LFENCE amalepheretsa kutsata malangizo onse mpaka zomwe zidawerengedwa kale zitatha. Mwachiwonekere, izi zimakhudza magwiridwe antchito a mapurosesa. Wofufuzayo adapeza kuti pafupifupi, chitetezo cha SESES chinachepetsa liwiro la kumaliza ntchito pogwiritsa ntchito laibulale yotetezedwa ndi 7,1%. Kuchepetsa zokolola pankhaniyi kudachokera 4 mpaka 23%. Kuneneratu koyambirira kwa ofufuzawo kunali kokayikitsa kwambiri, kuyitanitsa kuchepa kwa magwiridwe antchito ka 19.

Source: 3dnews.ru