Date: Thu, 29 May 2014 01:48:11 -0300 From: Fred Pedrisa <fredhps10@hotmail.com> To: "'Adrian Chadd'" <adrian@freebsd.org> Cc: 'freebsd-current' <freebsd-current@freebsd.org>, 'Jan Bramkamp' <crest@rlwinm.de> Subject: RES: KQueue vs Select (NetMap) Message-ID: <COL131-DS1365793231D36C08BC1079B0240@phx.gbl> In-Reply-To: <CAJ-VmomB=30k1T8u6p1Zd-eQhhkb1FygX87OrTpziHe0gYPC8w@mail.gmail.com> References: <COL131-DS24C9EC384D928E5FEB71C3B0240@phx.gbl> <00c301cf7aee$b00caea0$10260be0$@rlwinm.de> <COL131-DS25BDC42287725E7A2D3344B0240@phx.gbl> <CAJ-VmomB=30k1T8u6p1Zd-eQhhkb1FygX87OrTpziHe0gYPC8w@mail.gmail.com>
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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=20 > 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=20 > 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=20 > 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.=20 > It is mostly used by application dealing with a large amount of=20 > non-blocking sockets (or other file descriptors). It reduces overhead=20 > inherent in > select() and poll() by preserving state between calls. It also=20 > supports multiple types of events (read ready, write ready, timer=20 > 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=20 > 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=20 > FreeBSD IP stack. > _______________________________________________ > freebsd-current@freebsd.org mailing list=20 > 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=20 > http://lists.freebsd.org/mailman/listinfo/freebsd-current > To unsubscribe, send any mail to = "freebsd-current-unsubscribe@freebsd.org"
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