Injiniyan Google ya ba da shawarar kariyar software na masu sarrafawa daga hare-haren LVI

Wani lokaci da ya gabata ya zama sananne game da wani sabon rauni a cikin speculated gine na Intel processors, wanda ake kira. Load Value Allurar (LVI). Intel yana da nasa ra'ayi game da haɗarin LVI da shawarwari don rage shi. Naku nau'in kariya daga irin waɗannan hare-haren shawara injiniya a Google. Amma dole ne ku biya tsaro ta hanyar rage aikin sarrafawa da matsakaicin 7%.

Mun lura a baya cewa haɗarin LVI ba ya cikin takamaiman tsarin da masu binciken suka gano ba, amma a cikin ainihin ƙa'idar harin tashar tashar LVI, wanda aka nuna a karon farko. Don haka, an buɗe sabon jagora don barazanar da babu wanda ya taɓa zargin a baya (akalla, ba a tattauna wannan a cikin sararin samaniya ba). Sabili da haka, ƙimar ci gaban ƙwararren ƙwararren Google Zola Bridges ya ta'allaka ne a cikin gaskiyar cewa facin sa yana rage haɗarin ko da sabbin hare-haren da ba a san su ba dangane da ka'idar LVI.

A baya a cikin GNU Project Assembler (Mai tattara GNU) an yi canje-canje waɗanda ke rage haɗarin raunin LVI. Waɗannan canje-canje sun ƙunshi ƙarawa umarnin shinge LFENCE, wanda ya kafa tsari mai tsauri tsakanin hanyoyin ƙwaƙwalwar ajiya kafin da bayan shamaki. Gwajin facin akan ɗayan na'urorin sarrafa ƙarni na Intel's Kaby Lake ya nuna raguwar aiki har zuwa 22%.

Mai haɓaka Google ya ba da shawarar facinsa tare da ƙarin umarnin LFENCE zuwa saitin mai tarawa na LLVM, kuma ya kira SESES kariyar (Speculative Execution Side Effect Suppression). Zaɓin kariyar da ya gabatar yana rage barazanar LVI da sauran makamantan su, misali, Specter V1/V4. Aiwatar da SESES tana ba mai tarawa damar ƙara umarnin LFENCE a wurare masu dacewa yayin ƙirƙirar lambar injin. Misali, saka su kafin kowace umarni don karantawa daga ƙwaƙwalwar ajiya ko rubutu zuwa ƙwaƙwalwar ajiya.

Umarnin LFENCE yana hana ƙaddamar da duk umarni masu zuwa har sai an kammala karatun ƙwaƙwalwar ajiyar baya. Babu shakka, wannan yana rinjayar aikin sarrafawa. Mai binciken ya gano cewa a matsakaici, kariyar SESES ta rage saurin kammala ayyuka ta amfani da ɗakin karatu mai kariya da kashi 7,1%. Matsakaicin raguwar yawan aiki a cikin wannan yanayin ya kasance daga 4 zuwa 23%. Hasashen farko na masu binciken ya kasance mafi rashin tunani, yana kira da a rage yawan aiki har sau 19.

source: 3dnews.ru