Date: Tue, 25 Jun 2013 20:10:02 GMT From: Mark Johnston <markj@freebsd.org> To: freebsd-bugs@FreeBSD.org Subject: Re: kern/179975: igb(4) fails to do polling(4) Message-ID: <201306252010.r5PKA27Y065430@freefall.freebsd.org>
next in thread | raw e-mail | index | archive | help
The following reply was made to PR kern/179975; it has been noted by GNATS. From: Mark Johnston <markj@freebsd.org> To: Antoine Beaupre <anarcat@koumbit.org> Cc: bug-followup@freebsd.org Subject: Re: kern/179975: igb(4) fails to do polling(4) Date: Tue, 25 Jun 2013 16:10:10 -0400 On Tue, Jun 25, 2013 at 03:39:32PM -0400, Antoine Beaupre wrote: > > >Number: 179975 > >Category: kern > >Synopsis: igb(4) fails to do polling(4) > >Confidential: no > >Severity: serious > >Priority: medium > >Responsible: freebsd-bugs > >State: open > >Quarter: > >Keywords: > >Date-Required: > >Class: sw-bug > >Submitter-Id: current-users > >Arrival-Date: Tue Jun 25 19:50:00 UTC 2013 > >Closed-Date: > >Last-Modified: > >Originator: Antoine Beaupre > >Release: FreeBSD 9.1-RELEASE-p3 amd64 > >Organization: > Koumbit.org > >Environment: > System: FreeBSD rtr1.koumbit.net 9.1-RELEASE-p3 FreeBSD 9.1-RELEASE-p3 #0 r251605: Mon Jun 10 16:17:26 EDT 2013 root@rtr1.koumbit.net:/usr/obj/usr/src/sys/KOUMBIT1 amd64 > > >Description: > > the igb(4) driver doesn't work properly in polling mode, despite advertising that capability. > > [snip snip] > > This may be related with http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/155030 > > >Fix: > > No known fix. Workaround: > > ifconfig igb0 -polling > ifconfig igb0 polling > > It seems that cycling the polling configuration fixes the problem, at least temporarily. > > We have yet to put this server in production and would really, really appreciate some help here. We are a small non-profit ISP, but we are skilled enough to test patches on the kernel tree, and would be ready to offer a bounty (100$?) to see this problem fixed quickly. > > Our ETA for production is july 9th. Hello, Prior to the change in the above-mentioned PR, igb's polling mode only worked with a single queue enabled. I submitted a patch to get it to work with multiple queues, and it was committed in r239109. It didn't make it into 9.1 though, so igb's polling mode with multiple queues is broken. You have two options. The first is to apply the above revision to your driver and recompile the kernel. I can help you with this if you need it. The second is to tell igb to only use one queue, using the following lines in /boot/loader.conf: hw.igb.num_queues=1 You'll need to reboot to apply it. I don't think there's really much reason to have multiple queues enabled in polling mode, I just had a special use case. HTH, -Mark
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201306252010.r5PKA27Y065430>