Date: Mon, 3 Oct 2011 13:21:56 +0300 From: Sami Halabi <sodynet1@gmail.com> To: Jack Vogel <jfvogel@gmail.com> Cc: "freebsd-net@freebsd.org" <freebsd-net@freebsd.org>, Hooman Fazaeli <fazaeli@sepehrs.com> Subject: Re: em(4) high latency w/o msix Message-ID: <CAEW%2Boga2_m=2C9pDmw4Epp3TgZZXHoOstOg2XfzNRqcR7P4DkA@mail.gmail.com> In-Reply-To: <CAFOYbckcT3H4%2BU=-anhA0jUpQRE6vQDgr31H8MQn%2BOVy%2BTw%2B6Q@mail.gmail.com> References: <4E886A3B.7000502@sepehrs.com> <CAFOYbcnUbdrCYyDdSeYOWVNL_vhH_zA1d5B=mgrkoUijHXj-SQ@mail.gmail.com> <4E896999.3020001@sepehrs.com> <CAFOYbckcT3H4%2BU=-anhA0jUpQRE6vQDgr31H8MQn%2BOVy%2BTw%2B6Q@mail.gmail.com>
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Hi, Sorry for the questuion. what are the benefits of MSIX ? i don't have on my FREEBSD 8.1-R a sysctl hw.em.msix ... i have em card 82751EB. is msix NIX related? Thanks in advance, Sami On Mon, Oct 3, 2011 at 11:20 AM, Jack Vogel <jfvogel@gmail.com> wrote: > Can you try the driver in 8.2 and possibly stable/8 to see the behavior > there. > > And, just curious, why are you disabling MSIX? > > Jack > > > On Mon, Oct 3, 2011 at 12:51 AM, Hooman Fazaeli <fazaeli@sepehrs.com> > wrote: > > > ** > > Hi Jack > > > > The hardware is a PCIe network appliance with 3 port modules. The ports I > > have > > used in the test are 82574L residing on a 4 port module. Anyway, as I > noted > > in last mail, the stock 7.3-RELEASE driver does not expose this problem > on > > the same hardware. > > > > > > On 10/2/2011 7:38 PM, Jack Vogel wrote: > > > > On what hardware? > > > > Jack > > > > > > On Sun, Oct 2, 2011 at 6:42 AM, Hooman Fazaeli <fazaeli@sepehrs.com > >wrote: > > > >> > >> Latest em(4) driver from HEAD seems to have high latency > >> when MSIX is disabled. > >> > >> With MSIX enabled (hw.em.enable_msix=1): > >> > >> # ping -c5 192.168.1.83 > >> PING 192.168.1.83 (192.168.1.83): 56 data bytes > >> 64 bytes from 192.168.1.83: icmp_seq=0 ttl=64 time=0.055 ms > >> 64 bytes from 192.168.1.83: icmp_seq=1 ttl=64 time=0.076 ms > >> 64 bytes from 192.168.1.83: icmp_seq=2 ttl=64 time=0.066 ms > >> 64 bytes from 192.168.1.83: icmp_seq=3 ttl=64 time=0.051 ms > >> 64 bytes from 192.168.1.83: icmp_seq=4 ttl=64 time=0.063 ms > >> > >> --- 192.168.1.83 ping statistics --- > >> 5 packets transmitted, 5 packets received, 0.0% packet loss > >> round-trip min/avg/max/stddev = 0.051/0.062/0.076/0.009 ms > >> > >> With MSIX disabled: > >> > >> # ping -c5 192.168.1.83 > >> PING 192.168.1.83 (192.168.1.83): 56 data bytes > >> 64 bytes from 192.168.1.83: icmp_seq=0 ttl=64 time=0.180 ms > >> 64 bytes from 192.168.1.83: icmp_seq=1 ttl=64 time=0.164 ms > >> 64 bytes from 192.168.1.83: icmp_seq=2 ttl=64 time=0.169 ms > >> 64 bytes from 192.168.1.83: icmp_seq=3 ttl=64 time=0.172 ms > >> 64 bytes from 192.168.1.83: icmp_seq=4 ttl=64 time=0.167 ms > >> > >> --- 192.168.1.83 ping statistics --- > >> 5 packets transmitted, 5 packets received, 0.0% packet loss > >> round-trip min/avg/max/stddev = 0.164/0.170/0.180/0.005 ms > >> > >> As you see, w/o MSIX, RTT increases by a factor of 3. > >> > >> I also tested the following drivers: > >> - igb(4) from HEAD: OK. > >> - Stock 7.3-RELEASE: OK. > >> - Stock 7.4-RELEASE: problem exist. > >> > >> Any ideas? > >> > >> > >> > >> > >> > > > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org" > -- Sami Halabi Information Systems Engineer NMS Projects Expert
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