debloat-testing: Kitten not eaten - was Re: [Bloat] Please enter issues into the issue tracker - Issue system organisation needed.

[Jim Gettys]

On 02/24/2011 06:18 PM, Dave Täht wrote:
> Jim Gettys<jg at freedesktop.org>  writes:
>
>> On 02/24/2011 01:31 PM, Dave Täht wrote:
>>
>>> There is a debloat-testing Linux kernel repo up at:
>>>
>>> http://git.infradead.org/debloat-testing.git
>>>
>>> It builds, I haven't booted into it yet. The patch set is pretty minor,
>>> if you already have a Linux-2.6 tree it pays to use:
>>>
>>> git clone --references your_existing_tree  git://git.infradead.org/debloat-testing.git
>>>
>>> (Doesn't have SFB yet, either. John?)
>>
>> I built it; it booted, worked on my eDP display, and did my usual ping
>> + scp test (to a local system, so that the 802.11 would be saturated).
>>
>> OOTB, it controls the latency quite decently (no more than a few
>> milliseconds), but the drop rate on the ICMP running at the same time
>
> This brings the iwl driver down from 130+ms to a few ms!?

rtt min/avg/max/mdev = 0.646/3.631/32.951/5.487 ms

>
> How many more orders of magnitude do you need for *awesome*, rather than decent?

Well, we have to do some computation from first principles here.  I 
happened to be running G, so there is about 20Mbps goodput available.

If we have 1 packet queued to keep the interface busy all the time, that 
should insert something like a 1/2 of one millisecond of latency to 
another flow (if I did my math right).

So being in the 3-4ms range is still off by a bit.  But we're now much 
closer to where we should be, that where we started, so consider this 
major progress.

>
>> is quite high (~25%).  Pretty uncontrolled experiment; my son is home
>> ;-).
>
> That IS high. Perhaps the iwl and the linvilles alg are competing
> overmuch. Does your card do aggregation?
>
No clue; its a iwl6200agn; which is pretty recent; but I was running g.

Running n, I'm still getting high icmp (~25%) loss rates; the bandwidth 
goodput is staying about the same.  Then again, it's only running at 
54Mbps, so that makes sense.

rtt min/avg/max/mdev = 0.671/2.439/6.018/1.411 ms
			- Jim