Roel Janssen <r...@gnu.org> skribis: > Ludovic Courtès writes: > >> I agree that we could do a lot more things with a faster ‘guix >> environment’. My guess is that it won’t be easy to go optimize, and >> very hard to go below 1 second. We should profile that and see what can >> be done. > > FWIW, on our NFS-mounted /gnu, the 'guix environment' command takes at > least 20 seconds, but for any reasonably big environment it takes more > than one minute. The biggest bottleneck here is the disk latency. > Could it be that 'guix environment' accesses many files? If we could > reduce that, it would speed things up (at least for us ;)).
Interesting. Does guix-daemon access /gnu over NFS too? Could you send the output of (first run the same command without ‘strace’): strace -c guix environment --ad-hoc coreutils --pure -- true On my laptop I get: --8<---------------cut here---------------start------------->8--- $ strace -c guix environment --ad-hoc coreutils --pure -- true % time seconds usecs/call calls errors syscall ------ ----------- ----------- --------- --------- ---------------- 37.84 0.017268 1 14036 10965 stat 15.13 0.006904 1 9990 read 14.02 0.006398 1 10000 write 8.75 0.003991 3991 1 wait4 6.06 0.002764 1 5218 4 lstat 4.73 0.002157 1 1930 136 open 2.58 0.001176 1 1794 close 2.08 0.000949 1 1717 3 lseek 2.04 0.000932 1 689 mmap 1.89 0.000861 1 645 mprotect 1.71 0.000781 4 189 32 futex […] --8<---------------cut here---------------end--------------->8--- We stat a lot mostly to access all the Guix modules. Are they on NFS too? Thanks, Ludo’.
