Re: erlang:system_info(cpu_topology) strange behavior
Frank Muller <[email protected]>
| Newsgroups | gmane.comp.lang.erlang.general |
|---|---|
| Message-ID | <CAFA6GnBK1bashF-v=rrXXVjjSMUCZsLivRba+SGsBfg=YvkzEw@mail.gmail.com> |
Thanks Rickard. 8 oct. 2020 at 19:47, Rickard Green <[email protected]> wrote > On Thu, Oct 8, 2020 at 7:36 PM Frank Muller <[email protected]> > wrote: > >> Answering my own question. >> >> The second attempt worked because I was under “root”. >> >> Attaching to the release with -remsh failed because the node was running >> under user “orca” which has less privileges. >> >> Is this an expected behavior? >> >> /Frank >> >> > The runtime system gets the information about cpu topology by reading > files under /sys/devices/system/. If it cannot read and parse the files > there, it will fail to detect the cpu topology. Seems like only root is > allowed to read that part of the file-system in your case. > > Regards, > Rickard Green > > > >> Frank<[email protected]> >> >>> Hi guys, >>> >>> When I attached (-remsh) to my release application (/opt/orca), this >>> call returns undefined: >>> >>> ([email protected])1> erlang:system_info(cpu_topology). >>> undefined >>> >>> If try this instead, the call seems to work as expected: >>> >>> $ /opt/orca/erts-10.7.2.4/bin/erl >>> 1> erlang:system_info(cpu_topology). >>> [{processor,[{core,[{thread,{logical,0}}, >>> {thread,{logical,4}}]}, >>> {core,[{thread,{logical,1}},{thread,{logical,5}}]}, >>> {core,[{thread,{logical,2}},{thread,{logical,6}}]}, >>> {core,[{thread,{logical,3}},{thread,{logical,7}}]}]}] >>> >>> >>> I’m on Ubuntu16 LTS kernel 4.4.0, Erlang 22.3.4.11. >>> >>> Help appreciated >>> >>> /Frank >>> >> > > -- > Rickard Green, Erlang/OTP, Ericsson AB >