Re: [gentoo-dev] preformance in gentoo

[Brian Jackson]

On Thursday 10 April 2003 02:44 am, Eske Christiansen wrote:
> On Thu, Apr 10, 2003 at 07:06:28AM +0800, William Kenworthy wrote:
> > But is it a "real" problem or just the way you have configured the
> > kernel?  One respondent suggested low latency: have you configured the
> > kernel the same as the redhat one?  Is large memory selected in gentoo
> > and not redhat etc?
>
> Don't you think that a syscall to tcp select that is 5 times slower is a
> problem. I do.

Not always, if reliability goes 5x it's well worth it to me in some cases.

>
> > Are you going to use it as a server or workstation: I would look at
> > first benchmarking same against same, then configuring gentoo for the
> > task and look at any advantages (e.g., low latency for instance, not
> > just raw speed which is more a server thing) you get there.  Does redhat
> > do Low Latency as standard in its workstation kernels?
>
> As I stated it, it is used in a cluster where the conection is a giga-
> bit ethernet. In that case I want TCP select to as fast as it can be.
> I can see that redhat can make i 5 times faster.
> If the gentoo kernel is not best performance kernel that is offered in
> gentoo don't you think that an update to the installation text is in order.

Sometimes speed comes at a sacrifice to other things notably stability and 
cleanliness(see recent discussions of vendor kernels on LKML archives to see 
Red Hat emplyees bad mouthing the cleanliness of RH kernels). Not everybody 
is solely interested in speed. I have made compromises on most of my servers 
that lean them more toward stability, because I don't like getting pages in 
the middle of the night because some kernel patch wasn't exactly right. It 
all depends on what you need. That is why most people are drawn to Gentoo. 
The installation documanetation should be taken as a bare minimum to get a 
system up and running, from there you are on your own to find out what suits 
you best. I personally wouldn't use the RH sources if somebody paid me, they 
change too many things. They can't keep up with all that stuff sometimes(no 
offense to the RH guys, I know it is a full time job just reading LKML not to 
mention getting some other work done during the day)

>
> What we could do in gentoo is to make a gentoo-soruces-workstation and a
> gentoo-sources-server, so we can get a kernel that fit the workstation use
> and a kernel optimized for raw speed.

There are already tons of different patchsets out there, people would be 
better off using one of them. I use aa kernels on most of my servers and a 
mixture of ck and wolk sources on most of my desktops. 

>
> eske
<snip>

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