Messages in this thread | | | Date | Wed, 17 Jul 2013 14:22:39 -0400 | From | Joseph Salisbury <> | Subject | Re: [Regression][v3.10][v3.11] net: Kill link between CSUM and SG features. |
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On 07/17/2013 01:45 PM, Haiyang Zhang wrote: > >> -----Original Message----- >> From: Joseph Salisbury [mailto:joseph.salisbury@canonical.com] >> Sent: Wednesday, July 17, 2013 8:31 AM >> To: Pravin Shelar >> Cc: davem@davemloft.net; ben.howard@canonical.com; >> edumazet@google.com; xiyou.wangcong@gmail.com; >> alexander.h.duyck@intel.com; jiri@resnulli.us; netdev@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.salisbury@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.salisbury@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 <pshelar@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 > That's great. Thanks, Haiyang!
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