Re: gif(4) MP-ify by psref [was Re: passive references]

[Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>]

Hi,

On 2016/05/20 22:02, Taylor R Campbell wrote:
>    Date: Fri, 20 May 2016 16:28:15 +0900
>    From: Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>
> 
>    I back to gif(4) MP-ify, since I could eliminate bottleneck of
>    MP-scalable bridge(4) to support wm(4) TX multiqueue.
> 
>    I rebase my gif(4) MP-ify patches and reflect latest psref(9) and
>    pslist(9) implementation. Here is the patch series.
>        http://www.netbsd.org/~knakahara/gif-psref/gif-psref.tgz
>    And here is the unified patch.
>        http://www.netbsd.org/~knakahara/gif-psref/unified-gif-psref.patch

I rebase and improve the patches. Here is the updated patch series.
    http://www.netbsd.org/~knakahara/gif-mpify/gif-mpify.tgz
And here is the unified patch.
    http://www.netbsd.org/~knakahara/gif-mpify/unified-gif-mpify.patch

> Nice!  I don't have time to review it right now, but I'll try to find
> some time in the next few days.  Have you done any throughput tests
> yet, or tried observing the effect of `ifconfig gif1 create' on the
> flow through gif0?  I'm particularly curious to see how bad it is to
> just encap drop packets while `ifconfig gif1 create' is running.

I measure the throughput, however the effect is very little, that is,
nearly equal to accidental error. Additionally I create 1024 gif(4)s,
and then measure gif0 throughput while doing "ifconfig gif1025 create". 
The "ifconfig gif1025 create" effect is less than 1 percent(about 0.2%)
degradation.
In contrast, "ifconfig gif1 create" become slow while it flow nearly
limit performance packets on gif0. It takes about 2 or 3 seconds.
Furthermore, "ifconfig gif1025 create" become very slow under the same
condition. It takes over 10 seconds, or over 20 seconds in worst case.
# of course, if gif0 has no flow, ifconfigs finish immediately


If there is no objection, I will commit them after a few days or a few
weeks.


Thanks,

-- 
//////////////////////////////////////////////////////////////////////
Internet Initiative Japan Inc.

Device Engineering Section,
IoT Platform Development Department,
Network Division,
Technology Unit

Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>