This allows to fall back to the original Unix.select if preferred. It could be
useful for debugging purposes too.
Signed-off-by: Zheng Li <dev@zheng.li>
Reviewed-by: David Scott <dave.scott@citrix.com>
To go beyond 1024 fds, we also need to raise the process limitation on max
open fds (usually defaults to 1024).
We need to know the system level max open fds so that we won't go above that.
Simply setting the limit to RLIM_INFINITY doesn't work on Linux 3.x (EPERM), a
patch on this went into the 2.x branch but not 3.x for some reason.
Signed-off-by: Zheng Li <dev@zheng.li>
Reviewed-by: David Scott <dave.scott@citrix.com>
Currently, oxenstored uses Unix.select underneath, so it doesn't work properly
if given a FD number >= 1024. This is a scalability bottleneck for hosts
running large number of VMs.
To remove this limitation, we implemented a poll-based mechanism but with the
same type signature as the Unix.select currently in use. So these two functions
can be interchangeable at any stage.
Signed-off-by: Zheng Li <dev@zheng.li>
Reviewed-by: David Scott <dave.scott@citrix.com>