Re: [Patch 0/5] Support windowsize to benefit tftp/pxe download performance.

[Laszlo Ersek <lersek@redhat.com>]

On 09/19/18 04:20, Wu, Jiaxin wrote:
>> On 09/17/18 07:43, Jiaxin Wu wrote:
>>> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=886
>>>
>>> The series patches are to support the TFTP windowsize option described in
>> RFC 7440.
>>> TFTP shell command and UEFI PXE driver will use the feature to benefit the
>> download
>>> performance.
>>
>> I tested this series, between two virtual machines running on my laptop.
>> The TFTP server program that I used was "tftp-server-5.2-22.el7.x86_64".
>> The downloaded file was 478,150,656 bytes in size. I built OVMF with
>> NETWORK_IP6_ENABLE, so that the last patch would take effect for both
>> PXEv4 and PXEv6.
>>
>> Before the series:
>> - PXEv4:  75 seconds (~ 6225 KB/s)
>> - PXEv6: 100 seconds (~ 4669 KB/s)
>>
>> After the series:
>> - PXEv4: 48 seconds (~ 9728 KB/s)
>> - PXEv6: 60 seconds (~ 7782 KB/s)
>>
>> These measurements are very rough (I didn't run them multiple times
>> etc), but I think they are still quite good indicators.
>>
>> For the testing, I used the UEFI boot options in UiApp, and not the
>> shell command, hence I have no feedback on patch #3.
>>
>> For patches #1, #2, and #5:
>>
>> Tested-by: Laszlo Ersek <lersek@redhat.com>
>>
> 
> Thanks the verification.
> 
> 
>> However, as I pointed out elsewhere in the thread, I think:
>>
>> - You might want to port the changes from patch#5 to
>> "MdeModulePkg/Universal/Network/UefiPxeBcDxe" as well, in a separate
>> patch (patch #6).
>>
>> - If not, then (a) we should document this feature difference in the INF
>> files of the UefiPxeBcDxe drivers, (b) patch #4 should be re-done so
>> that it target NetworkPkg, not MdeModulePkg.
>>
> 
> As I said in the previous email, normally, we only add the new feature into the combo driver. But I think that's depends on the request. If you want to include the feature into MdeModulePkg/Universal/Network/UefiPxeBcDxe since the OVMF platform might use it, I will create patch #6. If not, I will follow the comments (a)/(b).

I don't currently have a use case or "requirement" for the window size
feature to work in an OVMF build that does *not* have
NETWORK_IP6_ENABLE. So from my side, we can delay the porting until such
a need materializes (it might never materialize, of course!)

However, because this information -- i.e., the feature separation
between the IPv4-only, and the combined IPv4/IPv6 driver -- is new to
me, can we please document it somewhere in the code, for example, in the
INF files? We don't have to spell out the TFTP window size feature by
name, just the fact that NetworkPkg's UefiPxeBcDxe has more features in
general (even such features that are orthogonal to internet protocol
version, v4 vs. v6).

If such documentation already exists, then I missed it, sorry!

Thanks!
Laszlo

>> - Patch #4 (regardless of package DEC) should be extended with
>> documentation (both DEC and UNI).
>>
>> Thanks
>> Laszlo