Date: Wed, 28 May 2014 21:49:59 -0700 From: Adrian Chadd <adrian@freebsd.org> To: Fred Pedrisa <fredhps10@hotmail.com> Cc: freebsd-current <freebsd-current@freebsd.org>, Jan Bramkamp <crest@rlwinm.de> Subject: Re: KQueue vs Select (NetMap) Message-ID: <CAJ-Vmokre=QHtVX5-vZD-hg-w6ZGj3j0YRVtbw29dfqXhLi2UQ@mail.gmail.com> In-Reply-To: <COL131-DS1365793231D36C08BC1079B0240@phx.gbl> References: <COL131-DS24C9EC384D928E5FEB71C3B0240@phx.gbl> <00c301cf7aee$b00caea0$10260be0$@rlwinm.de> <COL131-DS25BDC42287725E7A2D3344B0240@phx.gbl> <CAJ-VmomB=30k1T8u6p1Zd-eQhhkb1FygX87OrTpziHe0gYPC8w@mail.gmail.com> <COL131-DS1365793231D36C08BC1079B0240@phx.gbl>
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On 28 May 2014 21:48, Fred Pedrisa <fredhps10@hotmail.com> wrote: > Hello, > > Ok, but in practice, is there any performance gain by moving from select to kQueue implementation ? Or is it not significant at all ? > > -----Mensagem original----- > De: adrian.chadd@gmail.com [mailto:adrian.chadd@gmail.com] Em nome de Adrian Chadd > Enviada em: quinta-feira, 29 de maio de 2014 01:46 > Para: Fred Pedrisa > Cc: Jan Bramkamp; freebsd-current > Assunto: Re: KQueue vs Select (NetMap) > > The advantage is being able to include it in the rest of a kqueue IO loop where it's doing other things. > > > -a > > On 28 May 2014 20:53, Fred Pedrisa <fredhps10@hotmail.com> wrote: >> Hello, >> >> Yes, but kqueue support was added in recent commits as it says in the >> netmap changelog, is there any advantage ? >> >> -----Mensagem original----- >> De: owner-freebsd-current@freebsd.org >> [mailto:owner-freebsd-current@freebsd.org] Em nome de Jan Bramkamp >> Enviada em: quinta-feira, 29 de maio de 2014 00:30 >> Para: freebsd-current@freebsd.org >> Assunto: Re: KQueue vs Select (NetMap) >> >> >> On 29.05.2014 03:04, Fred Pedrisa wrote: >>> Hey Guys, >>> >>> >>> >>> How does kQueue performs over select with netmap ? >> You are asking for a comparison between apples and oranges. Netmap is >> an API for high performance access to the low-level features of modern >> NICs. It works on batches of frames in hardware queues. >> >> The kqueue() and kevent() system calls are an event notification API. >> It is mostly used by application dealing with a large amount of >> non-blocking sockets (or other file descriptors). It reduces overhead >> inherent in >> select() and poll() by preserving state between calls. It also >> supports multiple types of events (read ready, write ready, timer >> expired, async i/o, etc.). >> >> Afaik the netmap pseudo-device supports only select() and poll(). This >> is no performance problem because every thread will only deal with a >> small number of file descriptors to netmap devices. >> >> Netmap is designed to bypass the FreeBSD IP stack (for most frames). >> Kqueue is designed to scale to many sockets per process within the >> FreeBSD IP stack. >> _______________________________________________ >> freebsd-current@freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-current >> To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org" >> >> _______________________________________________ >> freebsd-current@freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-current >> To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org" >
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