Facebook yakagadzira yakavhurika PCIe kadhi ine atomic wachi

Mazuva mashoma apfuura nhau dzakaburitswa idzo Facebook yakaburitsa zviitiko zvine chekuita ne kusikwa kwe PCIe bhodhi, chii chakabatanidzwa lkumisikidzwa kweiyo diki atomiki wachi uye inogamuchira yeGNSS.

Iyo bhodhi yakatanga yakagadzirirwa sedare modular, ichibvumira kushandiswa kwemhando dzakasiyana dzekutengesa dziripo atomic wachi machipisi uye maGNSS module, senge SA5X, mRO-50, SA.45s, uye u-blox RCB-F9T. Orolia inotarisira kutanga kugadzirwa kwemabhodhi apera kugadzirirwa zvakatemwa.

Kadhi renguva iri kuvandudzwa sechikamu cheiyo yakawanda yepasirose nguva kifaa chirongwa inoitirwa kupa zvikamu zvekugadzirwa kwepuraimendi nguva maseva (Nguva Tenzi) (Vhura Nguva Server) iyo inogona kuitiswa mune yako zvivakwa uye kushandiswa, semuenzaniso, kuronga nguva yekufananidza munzvimbo dze data.

Uchishandisa yakamira sevha inokutendera iwe kuti usavimbe nevekunze network masevhisi kuwiriranisa iyo chaiyo nguva, uye kuvapo kweyakavakirwa-mukati maatomu wachi inopa yakakwira dziviriro mukuitika kwekutadza mukutambira dhata kubva kumasatelite masystem (semuenzaniso nekuda kwemamiriro ekunze kana kurwiswa).

Iyo nyowani yeNTP-yakavakirwa nguva yekuvakisa inoshandisa Stratum 1, chinhu chakakosha chakanangana neicho chiremera nguva sosi, senge yepasi rese satellite satellite system (GNSS) kana cesium wachi.

Izvo zvakasarudzika yeprojekti ndeyekuti kuvaka yekutanga nguva server, unogona kushandisa yakajairika server zvichibva pakuvakwa kweX86, iyo inosanganisira yakajairika kadhi network uye kadhi yenguva.

Pane akadaro server, chaiyo nguva ruzivo rwunogamuchirwa kubva kuma satellite kuburikidza neGNSS uye wachi yeatomiki inoshanda seyakagadzika oscillator, ichibvumira yakakwirira nhanho yekuchengetedzwa muchiitiko chekuti hapana ruzivo rwunogamuchirwa kuburikidza neGNSS. Iko kutsauka kunogoneka kubva panguva chaiyo kuitira kutadza kugamuchira dhata kuburikidza neGNSS pane bhodhi rakarongerwa inofungidzirwa kunge ingangoita mazana matatu nanosecond pazuva.

Iye ocp_pt mutyairi yakagadzirirwa Linux y inorongwa kuverengerwa mune huru Linux 5.15 kernel.

Mutungamiriri zvishandiso PTP POSIX maficha (/ dev / ptp2), GNSS kuburikidza serial port / dev / ttyS7, wachi yeatomic kuburikidza neiyo serial port / dev / ttyS8 nemidziyo miviri i2c / dev / i2c- *, iyo kugona kweiyo wachi yeharadhi (PHC) inogona kuwanikwa kubva kunzvimbo yemushandisi.

Pakutanga iyo NTP (Network Nguva Protocol) server, zvinokurudzirwa kushandisa Chrony neNTPd, uye kana uchitanga iyo PTP (Precision Time Protocol) server, zvinokurudzirwa kushandisa ptp4u kana ptp4l pamwe chete ne phc2sys stack kupa kopi yenguva kukosha kubva paatomu wachi kuenda kuneti kadhi.

Kufambisa yekushanda kweiyo GNSS inogamuchira uye neatomu wachi Izvo zvinogona kuitwa mune zvese Hardware uye software. Iyo Hardware mashandiro eiyo pairing module inoitwa pachishandiswa FPGA, uye software vhezheni inoshanda padanho rekutarisa kwakatarwa kweiyo mamiriro eGNSS inogamuchira uye neatomu wachi kubva kune maficha senge ptp4l uye chronyd.

Icho chikonzero chekuvandudzwa kwebhodhi rakavhurika pachinzvimbo chekushandisa yakagadzirira-kushandisa-mhinduro inowanika mumusika, ndiyo yakasarudzika hunhu hwezvigadzirwa zvakadaro, izvo zvisingatitenderi isu kuti tione kuti kuiswa kwacho kwakarurama, software yakatsanangurwa haiteerere nezvinodiwa zvekuchengetedza. .

Iyo bhodhi inogona kushandiswa kuronga basa rezvakasiyana nguva yekuyananisa maseva. Magadzirirwo, schematics, BOM, Gerber, PCB, uye maCAD mafaera anodikanwa ekugadzira bhodhi yakatumirwa paGitHub.

mabviro: https://engineering.fb.com