[Regression][v3.10][v3.11] net: Kill link between CSUM and SG features.

[Regression][v3.10][v3.11] net: Kill link between CSUM and SG features.

[Joseph Salisbury]

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.


Thanks,

Joe

[0] http://pad.lv/1200243

Re: [Regression][v3.10][v3.11] net: Kill link between CSUM and SG features.

[Pravin Shelar]

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,
>
> Joe
>
> [0] http://pad.lv/1200243
>
> --
> To unsubscribe from this list: send the line "unsubscribe netdev" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [Regression][v3.10][v3.11] net: Kill link between CSUM and SG features.

[Joseph Salisbury]

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?


>
>
>> Thanks,
>>
>> Joe
>>
>> [0] http://pad.lv/1200243
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe netdev" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [Regression][v3.10][v3.11] net: Kill link between CSUM and SG features.

[Pravin Shelar]

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.

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?

Thanks.

>>
>>
>>> Thanks,
>>>
>>> Joe
>>>
>>> [0] http://pad.lv/1200243
>>>
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe netdev" in
>>> the body of a message to majordomo@vger.kernel.org
>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

Re: [Regression][v3.10][v3.11] net: Kill link between CSUM and SG features.

[Joseph Salisbury]

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.

>
> Thanks.
>
>>>
>>>> Thanks,
>>>>
>>>> Joe
>>>>
>>>> [0] http://pad.lv/1200243
>>>>
>>>> --
>>>> To unsubscribe from this list: send the line "unsubscribe netdev" in
>>>> the body of a message to majordomo@vger.kernel.org
>>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/

RE: [Regression][v3.10][v3.11] net: Kill link between CSUM and SG features.

[Haiyang Zhang]

> -----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

Re: [Regression][v3.10][v3.11] net: Kill link between CSUM and SG features.

[Joseph Salisbury]

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!