Date: Wed, 1 Oct 2014 23:15:53 +0200 From: Luigi Rizzo <rizzo@iet.unipi.it> To: Kim Shrier <kim@westryn.net> Cc: "freebsd-net@freebsd.org" <freebsd-net@freebsd.org>, Adrian Chadd <adrian@freebsd.org>, Elof Ofel <elofu17@hotmail.com>, "Alexander V. Chernikov" <melifaro@freebsd.org> Subject: Re: individual queue blocking entire rx unit on ixgbe (Re: How do I balance bandwidth over several virtual NICs?) Message-ID: <CA%2BhQ2%2Bi_Ujc-U7M6TRY%2BzZkgrhKzZF5%2BFTC2m6VCfVnBW0c5bg@mail.gmail.com> In-Reply-To: <2FAAD083-7EAF-4E5F-A3D5-0AFB08C4ED9D@westryn.net> References: <CA%2BhQ2%2BhYY7AWE7jJWAg8uYER2LRSPz8TcVPuamsRBLj_WQyakw@mail.gmail.com> <2FAAD083-7EAF-4E5F-A3D5-0AFB08C4ED9D@westryn.net>
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On Wed, Oct 1, 2014 at 11:12 PM, Kim Shrier <kim@westryn.net> wrote: > Not sure if this is related. I was testing on 10.1 beta3 and I was copyi= ng > approximately 250 GB of data to the test machine, I noticed that the > network would periodically slow down to about 4 mbits/sec or it would > pause for about 20 seconds and then continue at full speed. > > The ethernet interface on the test machine is: > > bge0: <Broadcom NetXtreme Gigabit Ethernet Controller, ASIC rev. > 0x57766001> mem 0xa0400000-0xa040ffff,0xa0410000-0xa041ffff irq 16 at > device 0.0 on pci1 > bge0: CHIP ID 0x57766001; ASIC REV 0x57766; CHIP REV 0x577660; PCI-E > =E2=80=8Bno that seems totally unrelated to this thread. We are talking specifically about the ixgbe / 82599 cheers luigi =E2=80=8B > > > The machine I am transferring from is using the em0 interface: > > em0: <Intel(R) PRO/1000 Network Connection 7.3.8> port 0xdc00-0xdc1f mem > 0xfb5e0000-0xfb5fffff,0xfb5dc000-0xfb5dffff irq 16 at device 0.0 on pci2 > > > I haven=E2=80=99t noticed any slow down when transferring between machine= s where > both sides are using the em driver. > > During the slow downs and pauses, when I had a top command running, > the process state would show up as =E2=80=9Cdp->dp=E2=80=9D or =E2=80=9Cr= l->l_=E2=80=9D instead of > something > normal like =E2=80=9Cselect=E2=80=9D or CPUn. > > If this is related, then maybe the problem is somewhere other than the > device > driver. > > Kim > > On Oct 1, 2014, at 3:48 AM, Luigi Rizzo <rizzo@iet.unipi.it> wrote: > > > reviving this thread: > > > > i am just running experiments on 10.1 beta3 and even > > setting dev.ix.*.fc=3D0 and flipping the interface up and down > > does not seem to help: if i read only from a subset of the > > queues, the entire rx unit stalls eventually. > > > > I need to drain all queues to keep moving. > > > > Just tested this with 8 instances of netmap-ipfw running > > on an 8-core machine (8 queues enabled). > > > > netmap-ipfw netmap:ix0-0 netmap:ix1-0 > > netmap-ipfw netmap:ix0-1 netmap:ix1-1 > > ... > > > > and the source on another box is blasting on multiple queues with > > > > pkt-gen -f tx -i ix0 -d 10.0.10.0-10.0.10.255 > > > > > > I going to look at the driver's code now to see if/how > > this issue can be addressed. > > > > cheers > > luigi > > > > > > On Tue, Sep 23, 2014 at 6:00 PM, Adrian Chadd <adrian@freebsd.org> > wrote: > > > >> Ah, this behaviour. > >> > >> It's called DROP_EN on the intel igb / ixgbe hardware. Grep the > >> drivers for that particular register bit/setting. > >> > >> Set that bit for an RX queue and it'll instruct the MAC to drop frames > >> destined if that RX ring is full to it and keep receiving on the other > >> rings. Otherwise yes, receiving on that ring with the ring full cuases > >> the MAC to stop receiving on all rings until that ring has free space. > >> > >> You flip this on with ixgbe and igb by disabling tx/rx flowcontrol > >> (sysctl dev.ix|igb.X.fc=3D0) before configuring the interface. > >> > >> > >> > >> -a > >> > > > > > > > > -- > > -----------------------------------------+-----------------------------= -- > > Prof. Luigi RIZZO, rizzo@iet.unipi.it . Dip. di Ing. dell'Informazione > > http://www.iet.unipi.it/~luigi/ . Universita` di Pisa > > TEL +39-050-2211611 . via Diotisalvi 2 > > Mobile +39-338-6809875 . 56122 PISA (Italy) > > -----------------------------------------+-----------------------------= -- > > _______________________________________________ > > 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" > > --=20 -----------------------------------------+------------------------------- Prof. Luigi RIZZO, rizzo@iet.unipi.it . Dip. di Ing. dell'Informazione http://www.iet.unipi.it/~luigi/ . Universita` di Pisa TEL +39-050-2211611 . via Diotisalvi 2 Mobile +39-338-6809875 . 56122 PISA (Italy) -----------------------------------------+-------------------------------
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