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Re: [RESEND] tuning linux for high network performance?

To: bert hubert <ahu@xxxxxxx>
Subject: Re: [RESEND] tuning linux for high network performance?
From: Roy Sigurd Karlsbakk <roy@xxxxxxxxxxxxx>
Date: Wed, 23 Oct 2002 15:41:02 +0200
Cc: netdev@xxxxxxxxxxx, Kernel mailing list <linux-kernel@xxxxxxxxxxxxxxx>
In-reply-to: <20021023130101.GA646@xxxxxxxxxxxxxxx>
Organization: ProntoTV AS
References: <200210231218.18733.roy@xxxxxxxxxxxxx> <200210231306.18422.roy@xxxxxxxxxxxxx> <20021023130101.GA646@xxxxxxxxxxxxxxx>
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> '50 clients *each* streaming at ~4.4MBps', better make that clear,
> otherwise something is *very* broken. Also mention that you have an e1000
> card which does not do outgoing checksumming.

just to clearify

s/MBps/Mbps/
s/bps/bits per second/

> You'd think that a kernel would be able to do 250megabits of TCP checksums
> though.
>
> > ...adding the whole profile output - sorted by the first column this
> > time...
> >
> > 905182 total                                      0.4741
> > 121426 csum_partial_copy_generic                474.3203
> >  93633 default_idle                             1800.6346
> >  74665 do_wp_page                               111.1086
>
> Perhaps the 'copy' also entails grabbing the page from disk, leading to
> inflated csum_partial_copy_generic stats?

I really don't know. Just to clearify a little more - the server app uses 
O_DIRECT to read the data before tossing it to the socket.

> Where are you serving from?

What do you mean?

roy
-- 
Roy Sigurd Karlsbakk, Datavaktmester
ProntoTV AS - http://www.pronto.tv/
Tel: +47 9801 3356

Computers are like air conditioners.
They stop working when you open Windows.



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