Re: linux 2.2.19pre and thttpd (VM-global problem?)

[Petru Paler <ppetru@ppetru.net>]

On Fri, Dec 29, 2000 at 07:13:28PM +0100, Jakob Østergaard wrote:
> > > It can't scale in SMP.
> > 
> > No one said it does, but it works nicely on UP.
> 
> What ?

Maybe you got me wrong (my english isnt that good): I said that it does
not scale on SMP, but it works just fine on UP.

> The TCP stack is threaded, so things like checksum calculation will
> take advantage of multiple processors - right ?

Wrong. "Threaded" TCP/IP stack -> fine grained locking, not "multiple
threads".

> Thes rest of the work is roughly copying data that isn't already
> cached from the disk into memory.  Well, you have one disk so threads
> will buy you zero there.
> 
> Unless you do blocking I/O on the files or on the sockets, I fail to
> see how threads could possibly boost the performance on a web server
> that serves *static*only* pages.

They do boost performance on SMP (because you can have N (N=nr. of CPUs)
threads serving data).

> (The reason I'm curious is because I'm about a month away from implementing
>  something that would run high-bandwidth TCP transfers and I'm planning
>  on keeping it single-threaded - unless someone can tell me that's a bad
>  idea)

Keep it single threaded if you run on UP only...

--
Petru Paler, mailto:ppetru@ppetru.net
http://www.ppetru.net - ICQ: 41817235
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/