Re: [Lse-tech] Re: 10.31 second kernel compile

yodaiken
2002-03-16T23:35:57Z

On Sat, Mar 16, 2002 at 02:05:17PM -0700, Richard Gooch wrote:
> > Why not? If you just ran vim on console you'd be more productive and
> > not need all those worthless processes.
>
> Yeah, right.

I was just trying to be nice.

> > At 4KB/page and 8bytes/pte a
> > 1G process will need at least 2MB of pte alone ! Add in the 4 layers,
> > the software VM struct, ...
>
> This isn't a dedicated bigass-image display box. It's a workstation.
> It's where I read email, hack kernels, write visualisation tools and
> stuff like that.
>
> And I can afford a few MiB of RAM for PTE's and such for *the one
> process which is mapping my huge data files*! That's effectively a
> small, one-time cost. Every other process doesn't have a significant
> PTE cost.

Well, it's a matter of target. I'm thinking about our customers who
do high grade image processing on a stream of gig+ bitmaps. They need
64 (some are already painfully stranded on Alphas) and they don't use these
boxes for email.

> > But sure, big pages are not always good.
>
> Hm. With wide TLB's, what are the benefits to big pages? One

tlb miss rates, mm structure overhead and setup/teardown, swap speed,

---------------------------------------------------------
Victor Yodaiken
Finite State Machine Labs: The RTLinux Company.
www.fsmlabs.com www.rtlinux.com