Date: Wed, 1 Oct 2014 15:12:30 -0600 From: Kim Shrier <kim@westryn.net> To: Luigi Rizzo <rizzo@iet.unipi.it> 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: <2FAAD083-7EAF-4E5F-A3D5-0AFB08C4ED9D@westryn.net> In-Reply-To: <CA%2BhQ2%2BhYY7AWE7jJWAg8uYER2LRSPz8TcVPuamsRBLj_WQyakw@mail.gmail.com> References: <CA%2BhQ2%2BhYY7AWE7jJWAg8uYER2LRSPz8TcVPuamsRBLj_WQyakw@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
Not sure if this is related. I was testing on 10.1 beta3 and I was copying 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 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’t noticed any slow down when transferring between machines 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 “dp->dp” or “rl->l_” instead of something normal like “select” 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=0 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=0) 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"
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?2FAAD083-7EAF-4E5F-A3D5-0AFB08C4ED9D>