Re: Cloning speed comparison, round II

From: Linus Torvalds <torvalds@osdl.org>
Date: Nov 12, 2005, 22:03 UTC
Message-ID: <Pine.LNX.4.64.0511121352500.3263@g5.osdl.org>
In-Reply-To: <20051112212030.GH30496@pasky.or.cz>

On Sat, 12 Nov 2005, Petr Baudis wrote:

> 
>  From kernel.org to machine X, it takes 20s, and from machine X to my
> home machine, it takes 20s. From kernel.org to my home machine, it takes
> 5 minutes.

That's a twilight zone moment ;)

The pack-file writer is even trying to be good about not doing lots of small writes (it should chunk things up into 8kB chunks) so it should actually be a nice network app and send full-sized TCP frames from the very beginning (and nagle should mean that it continues to do so even around the chunk boundaries, assuming the server is fast enough at generating the data).

But it's entirely possible that one of the paths between the machine has some logic that prioritizes known stream types - gives higher priority to http/ssh over "unknown" protocols. That's a bad thing to do (the whole point of the internet is that the smarts is in the end-points, not in the network), but with so much of the packets whizzing by being virus-generated crap, some places apparently do things like that.

			Linus