Support specififying non-default batch size #9
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Provide new interfaces to allow calling `sendmmsg` and `recvmmsg` with a non-default batch size, specified by API clients as a generic constant during compile time. This is presently 1024 on Linux and FreeBSD. The default batch size is increased to 128 on these platforms. Also update to minimally support FreeBSD. Not all Linux features are supported yet.
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| @@ -1084,6 +1224,8 @@ fn prepare_msg<B: AsPtr<u8>>( | |||
| }; | |||
| encoder.push(libc::IPPROTO_IP, libc::IP_PKTINFO, pktinfo); | |||
| } | |||
| #[cfg(target_os = "freebsd")] | |||
| Source::Interface(_) => (), // Not yet supported on FreeBSD | |||
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should we just disallow the variant itself on freebsd? if not, maybe some comment on Interface to indicate it can't be used with freebsd
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There's a way to do it, but I just didn't have time to investigate/verify. I don't have a FreeBSD development system, so I was mainly checking under cross (just to make sure it at least compiles).
See: rust-lang/libc#1583
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It might make sense to switch this to unimplemented!() (which is a bit stronger way to disallow it). Would need some corresponding documentation.
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thanks! quinn mentions the default batch size was "arbitrary", any reason behind the increase to 128 for the default? |
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My guess was that they just picked a reasonable default for the situation. In our use case, we easily exceed even the system cap (1024), so we're willing (and able) to forfeit some stack space to reduce the calls. However, small device applications might prefer a much smaller default to minimize the risk of stack overflows. |
Provide new interfaces to allow calling
send_mmsgandrecv_mmsgwith a non-default batch size, specified by API clients as a generic constant during compile time. This is presently 1024 on Linux and FreeBSD. The default batch size is increased to 128 on these platforms.Also update to minimally support FreeBSD. Not all Linux features are supported yet.