Re: [2.6.16-gitX] heavy performance regression in ipw2200 wirelessdriver

From: Andrew Morton
Date: Wed Mar 22 2006 - 22:12:13 EST


"Alessandro Suardi" <alessandro.suardi@xxxxxxxxx> wrote:
>

Pleeeeze try to cc the right people.

> Driver - or firmware ? Don't know - since the new git snapshots run
> 1.1.1 which requires newer firmware from http://ipw2200.sourceforge.net.
>
> Symptom -> my new FC5 partition with 2.6.16-git kernels connects via
> VNC viewer to my bittorrent box over wireless (ipw2200 to a D-Link
> G604T router/AP); Dell D610 runs FC5, BT box is a K7-800 running
> FC3 with a 2.6.16-rc5-git8 kernel (15+ days uptime...).
>
> I also run Firefox on the bittorrent box; noticed today (2.6.16-git5) that
> the screen refresh of pages with images was from time to time very
> slow (close to unusable).
>
> Rebooted into my FC4 partition with a 2.6.16 kernel, everything much
> snappier. So I ran a scp test from my BT server to the laptop, three
> times in a row the same file - a 38MB .flac with the laptop in the same
> physical position (ie, no signal variation). Results...
>
> FC5 - 2.6.16-git3:
>
> [asuardi@donkey melua_2004-09-23_Berlin]$ scp KM_9-23-04_17_The\
> Closest\ Thing\ to\ Crazy.flac 192.168.1.8:/tmp
> asuardi@xxxxxxxxxxx's password:
> KM_9-23-04_17_The Closest Thing to Crazy.flac 100% 38MB 971.3KB/s 00:40
> [asuardi@donkey melua_2004-09-23_Berlin]$ scp KM_9-23-04_17_The\
> Closest\ Thing\ to\ Crazy.flac 192.168.1.8:/tmp
> asuardi@xxxxxxxxxxx's password:
> KM_9-23-04_17_The Closest Thing to Crazy.flac 100% 38MB 1.3MB/s 00:29
> [asuardi@donkey melua_2004-09-23_Berlin]$ scp KM_9-23-04_17_The\
> Closest\ Thing\ to\ Crazy.flac 192.168.1.8:/tmp
> asuardi@xxxxxxxxxxx's password:
> KM_9-23-04_17_The Closest Thing to Crazy.flac 100% 38MB 626.7KB/s 01:02
>
>
> FC4 - 2.6.16:
>
> [asuardi@donkey melua_2004-09-23_Berlin]$ scp KM_9-23-04_17_The\
> Closest\ Thing\ to\ Crazy.flac 192.168.1.8:/tmp
> asuardi@xxxxxxxxxxx's password:
> KM_9-23-04_17_The Closest Thing to Crazy.flac 100% 38MB 1.5MB/s 00:25
> [asuardi@donkey melua_2004-09-23_Berlin]$ scp KM_9-23-04_17_The\
> Closest\ Thing\ to\ Crazy.flac 192.168.1.8:/tmp
> asuardi@xxxxxxxxxxx's password:
> KM_9-23-04_17_The Closest Thing to Crazy.flac 100% 38MB 1.7MB/s 00:23
> [asuardi@donkey melua_2004-09-23_Berlin]$ scp KM_9-23-04_17_The\
> Closest\ Thing\ to\ Crazy.flac 192.168.1.8:/tmp
> asuardi@xxxxxxxxxxx's password:
> KM_9-23-04_17_The Closest Thing to Crazy.flac 100% 38MB 1.7MB/s 00:22
>
> Bottom line - old driver has better performance than the new one,
> but most noticeably delivers consistent performance.
>
> I will be available for testing starting Thursday 30th as I'll be on
> the road since then. Of course if the problem is identified and
> fixed earlier, I won't cry ;)

Well. It's not a huge regression. It's a 50%ish regression. We've done
worse ;)

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