> -----Original Message----- > From: Joseph Salisbury [mailto:joseph.salisb...@canonical.com] > Sent: Wednesday, July 17, 2013 8:31 AM > To: Pravin Shelar > Cc: da...@davemloft.net; ben.how...@canonical.com; > eduma...@google.com; xiyou.wangc...@gmail.com; > alexander.h.du...@intel.com; j...@resnulli.us; net...@vger.kernel.org; > LKML; KY Srinivasan; Haiyang Zhang > Subject: Re: [Regression][v3.10][v3.11] net: Kill link between CSUM and SG > features. > > On 07/16/2013 04:50 PM, Pravin Shelar wrote: > > On Tue, Jul 16, 2013 at 12:53 PM, Joseph Salisbury > > <joseph.salisb...@canonical.com> wrote: > >> On 07/16/2013 02:29 PM, Pravin Shelar wrote: > >>> On Tue, Jul 16, 2013 at 11:09 AM, Joseph Salisbury > >>> <joseph.salisb...@canonical.com> wrote: > >>>> Hi Pravin, > >>>> > >>>> A bug was opened against the Ubuntu kernel[0]. After a kernel > >>>> bisect, it was found that reverting the following commit resolved this > bug: > >>>> > >>>> commit ec5f061564238892005257c83565a0b58ec79295 > >>>> Author: Pravin B Shelar <pshe...@nicira.com> > >>>> Date: Thu Mar 7 09:28:01 2013 +0000 > >>>> > >>>> net: Kill link between CSUM and SG features. > >>>> > >>>> > >>>> The regression was introduced as of v3.10-rc1. > >>>> > >>>> I see that you are the author of this patch, so I wanted to run > >>>> this by you. I was thinking of requesting a revert for v3.11, but > >>>> I wanted to get your feedback first. > >>>> > >>>> > >>> This issue was reported before and turning off sg solves problem for > >>> HyperV driver. Drivers (intel and bnx2x) that I tested works fine > >>> with this patch. Have you seen the issue on any other NIC? > >> Thanks for the feedback. We have only seen it on Intel hardware. > >> Can you send a pointer to the patch? If so, we can provide some > >> additional testing. Do you plan on submitting the patch for inclusion in > 3.11? > >> > >> > > What I mean is I do not see any problem with the patch that you have > > pointed out on ixgbe and bnx2x platforms. HyperV problem went away > > with disabling sg by ethtool utility. > Yes, we also see that the problem goes away when disabling sg with ethtool. > There was a significant improvement in throughput with sg enabled, so it's > unfortunate it must be disabled. > > > > > Can you also give me more information about regression you are seeing > > like driver name, features of the NIC set and features of device > > without this patch. Does any other NIC than HyperV having this issue? > > Some details info about the HyperV guest can be seen here: > http://paste.ubuntu.com/5884549/ > > In that output, you will see that scatter-gather is off, which was done > manually. > > Only a HyperV NIC is having this issue. I have submitted a patch which has been accepted, and queued for -stable branch as well: http://patchwork.ozlabs.org/patch/259596/ It removes the NETIF_F_SG flag from the hv_netvsc driver, which doesn't currently support SG mode.
Thanks, - Haiyang -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
