smp and kernel poll

Mikael Pettersson <>
Thu May 18 15:02:59 CEST 2006


Christophe Romain writes:
 > in erts/emulator/sys/unix/sys.c:37 we can see
 > #if defined(ERTS_SMP) && defined(USE_KERNEL_POLL)
 > #  error "smp support and kernel poll currently not supported (use 
 > poll)"
 > #endif
 > 
 > I would like to apply epoll patch from sipphone
 > http://developer.sipphone.com/ejabberd/erlang_epoll_patch/
 > and I wonder if there is an issue with SMP.

If I remember correctly from our SMP task group meetings,
the issue is not that epoll causes breakage, but that unix/sys.c
is an #ifdef mess so we want to limit the number of APIs we use.
One plan that was mentioned was to standardise on one API in sys.c
(say poll()) and to emulate it if e.g. select() or epoll() is the
underlying API, but that emulation is probably not implemented yet.

/Mikael



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