Performance issues due to the microkernel/multi-server system architecture?

IRC, freenode, #hurd, 2011-07-26

< CTKArcher> I read that, because of its microkernel+servers design, the
  hurd was slower than a monolithic kernel, is that confirmed ?
< youpi> the hurd is currently slower than current monolithic kernels, but
  it's not due to the microkernel + servers design
< youpi> the microkernel+servers design makes the system call path longer
< youpi> but you're bound by disk and network speed
< youpi> so the extra overhead will not hurt so much
< youpi> except dumb applications keeping doing system calls all the time
  of course, but they are usually considered bogus
< braunr> there may be some patterns (like applications using pipes
  extensively, e.g. git-svn) which may suffer from the design, but still in
  an acceptable range
< CTKArcher> so, you are saying that disk and network are more slowing the
  system than the longer system call path and because of that, it wont
  really matter ?
< youpi> braunr: they should sitll be fixed because they'll suffer (even if
  less) on monolithic kernels
< youpi> CTKArcher: yes
< braunr> yes
< CTKArcher> mmh
< youpi> CTKArcher: you might want to listen to AST's talk at fosdem 10
  iirc, about minix
< youpi> they even go as far as using an IPC for each low-level in/out
< youpi> for security
< braunr> this has been expected for a long time
< braunr> which is what motivated research in microkernels
< CTKArcher> I've already downloaded the video :)
< youpi> and it has been more and more true with faster and faster cpus
< braunr> but in 95, processors weren't that fast compared to other
  components as they are now
< youpi> while disk/mem haven't evovled so fast