Re: [gentoo-user] Re: Kernel compiles ... monitoring

[Alan McKinnon]

On Mon, 26 Sep 2011 18:04:24 -0500
Harry <hputnam3@×××××.com> wrote:

> Paul Hartman <paul.hartman+gentoo@×××××.com> writes:
>
> > On Mon, Sep 26, 2011 at 10:59 AM, Harry <hputnam3@×××××.com> wrote:
> >> How can one tell how far along a kernel compile is?  I can see the
> >> modules being
> >> built in /var/log/genkernel.log
> >>   (Aside: Please, no hysteria about using genkernel)
> >>
> >> But I'd like to know of some way to guesstimate how much of the
> >> process is completed.  Is there a list the compile has generated
> >> and is following somewhere under /usr/src/linux? Or some other way
> >> of knowing where the compile is in terms of percentage completed?
> >
> > All I can think of is: time it. Maybe you can create a wrapper
> > script to time it, record times (for successful builds only) and
> > measure progress based on estimated time remaining. Kind of like
> > what genlop does with emerge logs.
>
> Sounds like there is no real way unless as you say.  I've been
> wrestling with kernel build after kernel build trying to get a new
> install booted.  Many failures led me to finally resorting to
> genkernel... but you may know already that is a full day of compile at
> least.
>
> But I'm seeing really massive times even on the trimmed down kernels
> where I've set only known things I need.
>
> This is happening in a chroot from sysrescueCD on an older P4 with 2G
> ram.  But my god, I'm seeing hrs and hrs of compile time go by even on
> a lean mean menuconfig produced .config.
>
> Is this pretty normal?

No, that's very abnormal even for a P4. Something is badly wrong.

I get this in a VM with a clean set of kernel sources:

# genlop -t gentoo-sources
 * sys-kernel/gentoo-sources

     Sun Sep  4 23:08:52 2011 >>> sys-kernel/gentoo-sources-2.6.39-r3
       merge time: 6 minutes and 48 seconds.

The VM host is a flashy Samsung knock-off of an Apple Air with a nice
cpu (Intel(R) Core(TM) i5-2537M CPU @ 1.40GHz) and SSD.

The guest that did the compile is 1 cpu, 1G RAM and /var/tmp/portage
on the SSD. It's VirtualBox and while the compile was running I had 3
other VMs running and one of them was Windows7. Kernel compiles should
be quick, that same VM takes 90 minutes to build gcc.


My old ancient desktop was sort-of comparable to your P4, with IDE
disks and 1.5G RAM. Kernel compiles there took about 30-40 minutes.
sysrescueCD *shouldn't* make a difference as the entire chroot fs I
presume will be on hard disk.

What do your basics performance tools like top and friends say? See
what swap usage looks like outside the chroot while the compile is
running - is it thrashing? What speed are you getting for the hard disk
from hdparm -t -T?

How long does it take to build other big packages like gcc, glibc, 
maybe even binutils?


-- 
Alan McKinnnon
alan.mckinnon@×××××.com