Re: kernel wishlist for web server performance (fwd)

[Marc Slemko <ma...@znep.com>]

---------- Forwarded message ----------
Date: Mon, 9 Mar 1998 20:47:45 -0500 (EST)
From: Yiming Hu <hu...@ele.uri.edu>
To: freebsd-hackers@FreeBSD.ORG
Subject: Re: kernel wishlist for web server performance

 
>That is 50ish times the sustained speed of most disk drives.  And 25
>times faster than the fastest generally deployed network technology
>(100BaseT).
> 
>Anyway, we're talking at most 2-4% savings here at the cost of a huge
>amount of kernel bloat.
> 
>Warner
 
Well, in some systems, avoiding copying can result in a BIG save. 
I'm not sure about FreeBSD, but my experience on AIX shows that 
Apache can benefit a lot from "transfer-file" type system calls.
I believe that you can save more than 20-30% of CPU overhead on
a busy server.
 
I have a technology report at
 
    ftp://ele.uri.edu/pub/hu/TR10970001.ps.Z
 
which discusses this topic.  MIT's ServerOS paper is another good 
reference.
 
BTW, such a system call will not only improve Web server performance,
but also speed up file server performance, which also ships
large volume of data from the file-system (cache) to the network.
 
-Yiming 


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Re: kernel wishlist for web server performance (fwd)

[Marc Slemko <ma...@worldgate.com>]

Some interesting stuff in there, but some of it seems a bit... unsupported
and speculative, and it isn't always clear that the real issues behind
some of this stuff are understood.

On Fri, 20 Mar 1998, Marc Slemko wrote:

> 
> 
> ---------- Forwarded message ----------
> Date: Mon, 9 Mar 1998 20:47:45 -0500 (EST)
> From: Yiming Hu <hu...@ele.uri.edu>
> To: freebsd-hackers@FreeBSD.ORG
> Subject: Re: kernel wishlist for web server performance
> 
>  
> >That is 50ish times the sustained speed of most disk drives.  And 25
> >times faster than the fastest generally deployed network technology
> >(100BaseT).
> > 
> >Anyway, we're talking at most 2-4% savings here at the cost of a huge
> >amount of kernel bloat.
> > 
> >Warner
>  
> Well, in some systems, avoiding copying can result in a BIG save. 
> I'm not sure about FreeBSD, but my experience on AIX shows that 
> Apache can benefit a lot from "transfer-file" type system calls.
> I believe that you can save more than 20-30% of CPU overhead on
> a busy server.
>  
> I have a technology report at
>  
>     ftp://ele.uri.edu/pub/hu/TR10970001.ps.Z
>  
> which discusses this topic.  MIT's ServerOS paper is another good 
> reference.
>  
> BTW, such a system call will not only improve Web server performance,
> but also speed up file server performance, which also ships
> large volume of data from the file-system (cache) to the network.
>  
> -Yiming 
> 
> 
> To Unsubscribe: send mail to majordomo@FreeBSD.org
> with "unsubscribe freebsd-hackers" in the body of the message
>