Vatauri ve AMD vachangobva kuburitswa pachishandiswa chinyorwa chinyorwa umo icho chinoziviswa ruzivo rwekuongorora kunoitwa pamusoro pekuchengetedza kwe iyo tekinoroji yekugadzirisa PSF (Predictive Store Forwarding) inoitwa muma processor e Zen 3 dzakateerana.
Chidzidzo dzidziso yakasimbisa kushanda kweiyo Specter-STL yekurwisa nzira (Specter-v4) kune tekinoroji yePSF, inozivikanwa muna Chivabvu 2018, asi mukuita, hapana matemplate ekodhi anokwanisa kumutsa kurwisa haasati awanikwa, uye njodzi yakatarwa inoonekwa seisina basa.
The Record ataurwa kune nyanzvi yeGraz University of Technology, Daniel Gruss uyo akawana kuti AMD PSF inogona kutambura kune akasiyana emakosi echikamu kurwisa, ayo mumakore apfuura akagadzira zvakawanda.
Rangarira kuti iyo Specter-v4 kurwisa (Yekufungidzira Chitoro Kupfuura) inovimba nekudzosa data iro rakachengetwa mushure mekurasa mhedzisiro yekufungidzira kuisirwa mashandiro nekugadzirisa kumwe kuverenga nekunyora mashandisiro uchishandisa zvisina kunangana kugadzirisa.
Kana basa rekuverenga rikaenderera kune yekunyora kushanda (semuenzaniso, mov [rbx + rcx], 0x0; mov rax, [rdx + rsi]), kukanganisa kwenzira yekuverenga kunogona kunge kuchitozivikanwa Nekuda kwekuita kwakafanana (kuverenga mashandiro anoitwa kazhinji uye kuverenga kunogona kuitwa kubva cache) uye processor inogona kuverenga zvisirizvo usati wanyora, pasina kumirira kukanganisa kweasina kunyorera kunyora gwara kuti riverengwe.
Iyi ficha inobvumidza kuverenga kuraira kuti uwane iyo yapfuura kukosha munzira ipi neipi apo oparesheni yekuchengetedza ichakamirira. Kana paine kukanganisa kwekufungidzira, kukundikana kwekufungidzira kucharaswa, asi maratidziro ekuitwa kwayo acharamba ari mu processor cache uye anogona kudzoserwa achishandisa imwe yemaitiro ekugadzirisa zvemukati zvecache zvinoenderana neshanduro yekuongorora munguva yekuwana yakachengetwa uye isina-cached dhata.
Yakawedzerwa kune AMD Zen 3 processor, iyo tekinoroji PSF inogadziridza iyo Yekuchengetedza-Ku-Mutoro-Yekutumira nzira (STLF), inoita nenzira yekufungidzira mashandiro ekuverenga zvichienderana nekufungidzira kwehukama pakati pekuverenga nekunyora mashandiro. Iine STLF yechinyakare, processor inoita "mutoro" kushanda pane iyo data yakadzoserwa zvakananga kubva kumurairi wekare we "chitoro", isina kumirira kunyorwa chaiko kwemhedzisiro mundangariro, asi ichiona kuti kero dzinoshandiswa mu "mutoro" y Iyo "chitoro" mirairo inowirirana.
PSF optimization inogadzira kero yekufungidzira uye inoita "mutoro" mashandiro usati wapedza kero yeruzivo kuverenga, kana chitoro / mutoro peya yakambotorwa ichinyengedza kero. Kana fungidziro ikatadza, nyika inodzoka, asi iyo data inoramba iri mune cache.
Kurwiswa kwePSF chete zvinokwanisika mukati mehurongwa hwekuremekedzwa kwevezera rako, inongovhara chete mamiriro ezvino maitiro uye yakavharirwa nekero nzvimbo yekutsiva nzira kana Hardware sandbox michina. Nekudaro, software sandbox yekuzvipatsanura matekinoroji mune maitiro anogona kuve anogona kukanganiswa nenyaya.
Kurwiswa uku kunotyisidzira masisitimu akadai se mabhurawuza, kodhi yekumisikidza michina, uye maJIT anomhanya yechitatu-bato kodhi mukati meimwe nzira (semhedzisiro yekurwisa, isina kuvimbwa sandbox kodhi inogona kuwana kune imwe dhata pane ino maitiro).
AMD yakapa nzira dzakasiyana siyana dzekudzima PSF zvizere kana kusarudza, asi kupihwa njodzi isina basa kune akawanda manyorerwo, zvakakurudzira kuti usaremadza kuita uku nekukasira.
Zvekusarudzira kuchengetedza kwemaitiro ekuita kodhi isina kuvimbika iri yoga, zvinokurudzirwa kudzima PSF nekumisikidza iyo MSR bits "SSBD" uye "PSFD", kunyangwe shinda yega yega. Kune iyo Linux kernel, zvigamba zvakagadzirwa pamwe nekuitwa kwe "psfd" uye "nopsfd" yekuraira sarudzo sarudzo dzinodzora PSF kuvhura uye kudzima.
Kune avo vanofarira kugona kuziva chirevo, vanogona kubvunza chinotevera chinongedzo.