On Fri, Feb 12, 2016 at 5:26 PM, Ryota Ozaki <ozaki.ry...@gmail.com> wrote: > 2016/02/11 2:36 "Taylor R Campbell" <campbell+netbsd-tech-k...@mumble.net>: >> >> Date: Wed, 10 Feb 2016 18:56:46 +0900 >> From: Ryota Ozaki <ozak...@netbsd.org> >> >> Thanks to introducing softint-based if_input, >> we can simplify bridge(4). >> >> Awesome! I love patches that have loads more -'s than +'s, and >> simplify locking schemes, and remove sketchy cpu_intr_p conditionals, >> and things like that. >> >> Here is a patch: >> http://www.netbsd.org/~ozaki-r/simplify-bridge.diff >> >> Remove cpu_intr_p from BRIDGE_RT_RENTER/REXIT too? > > Definitely I forgot them :-/ Fixed. > >> >> I wonder how much of a difference BRIDGE_MPSAFE really makes on >> uniprocessor systems. If this were new code I wouldn't have done any >> conditional compilation of that. I can't imagine the performance >> impact is very high: maybe a few more words of memory are used, but >> uniprocessor mutex acquisition should be pretty cheap. Maybe in a >> future patch we can eliminate all that. > > I agree. I'll do that soon.
...not so much soon though, I prepared patches: http://www.netbsd.org/~ozaki-r/bridge-psz-list.diff http://www.netbsd.org/~ozaki-r/bridge-default-mpsafe.diff The first one introduces membar to list operations used in bridge for pserialize, and the other one removes BRIDGE_MPSAFE switch and make bridge MP-safe by default. The first one should be revisited once we have the official API of list operations for pserialize. ozaki-r
