4 ms·

Lightweight meaning 0.5kb for a BEAM process vs 1024kb for a JVM thread. A goroutine in Go is 2kb for comparison sake.

• masklinn 8y ago
  > lightweight meaning 0.5kb for a BEAM process It's quite a bit more than that. According to the offical doc[0] it's 309 words without SMP or HiPE, on my machine (with both) it's 336 words. That's 1.2~1.3k on a 32b system and 2.4~2.6 on a 64b system. [0] http://erlang.org/doc/efficiency_guide/processes.html http://erlang.org/doc/efficiency_guide/processes.html
  • derefr 8y ago
    Production Erlang systems tend to take advantage of hibernating many of their “millions of processes”, though, since it’s a rare architecture where those million processes are all hot. If you look at the memory usage of such systems, it’s a lot less than that figure would imply, mainly because of process hibernation.
    • masklinn 8y ago
      That is true, best-case scenario (a process storing no data whatsoever) hibernating can remove the 233 words minimal heap (and stack) preallocated, yielding 76 words without hipe or smp, or 103 with them, for 304 / 608 / 412 / 824 bytes (nothing/32, nothing/64, hipe+smp/32, hipe+smp/64).
  • brightball 8y ago
    I came across that number a couple of years ago when I was doing research for a presentation. It may have been from a book but I'll see if I can dig up the source.
    • masklinn 8y ago
      As derefr notes, it might have been the size of a hibernating (rather than live) process. It's 0.3~0.4k on 32b systems, though 0.6~0.8 on 64b ones.