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Date: Tue, 17 Apr 2001 21:24:43 +0300
From: Pekka Pietikainen <pp@evil.netppl.fi>
To: Jan Kasprzak <kas@informatics.muni.cz>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Possible problem with zero-copy TCP and sendfile()
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In-Reply-To: <20010417170206.C2589096@informatics.muni.cz> <E14pXxg-0002cI-00@the-village.bc.nu> <20010417181524.E2589096@informatics.muni.cz>
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On Tue, Apr 17, 2001 at 06:15:24PM +0200, Jan Kasprzak wrote:
> 	Some more progress: I now downgraded to proftpd without sendfile().
> The CPU usage is now nearly 100% (with ~170 FTP users; with sendfile()
> it was under 50% with >320 FTP users). But nevertheless, the downloaded
> images now seem to be OK.
> 
> 	Should I try the stock 2.4.3 without zero-copy patches?
It might also be useful to try 2.4.3+zc with the dev->features |=
NETIF_F_SG; in the 3c59x driver taken out (so it won't use zero-copy)

Since it starts from the beginning instead of corrupting random packets I
doubt it's a hardware problem, though.

-- 
Pekka Pietikainen



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