On Friday 27 July 2007 10:33:53 am Jeremy Huntwork wrote:
> On Fri, Jul 27, 2007 at 10:25:31AM -0400, kas wrote:
> > that the book changed that much. 64 bit was run from the CD whereas the
> > 32 bit build was run from the CD installed on a hard drive.
>
> This would kind of skew the accurateness of your test. Reads performed
> on a CD filesystem are noticeably slower than those from a hard disk. As
> you build /tools you are continuously reading and making use of items on
> the host system, in other words, the LiveCD. Since your SBU is measured
> by the first program you build, binutils, you would end up having a
> higher SBU for a system built from the CD than one from an internal
> disk.
>
> Of course, as the build progresses and you begin using more and more
> items on the hard-disk only, (first in /tools and then in chroot), the
> read time would increase.
>
> --
> JH
Ok, so I didn't think that the CD was making much difference as the activity
led was never on for more than a flash ... but I had to be sure so I ran from
the r1952 LiveCD to do a 32 bit jhalfs-2.2 build on the same hardware (yes, I
removed 2.1 and untarred 2.2 in its place). As before, I didn't build a
kernel. So I was using a slightly different kernel but everything else was
the same. The same swap partition was mounted in both cases.
32-bit build using the r1952 LiveCD
-----------------------------------
Book version is: SVN-20070726
Using logs/028-binutils-pass1 to obtain the SBU unit value.
The SBU unit value is equal to 151.428 seconds.
Total time required to build the systen: 76.144 SBU
Total Installed files disk usage
(including /tools but not /sources): 538912 KB or 526.29 MB
Build time comes out 192 minutes ... CD access time was lost in the noise as
the run from the hard drive took 192 mins also ... the same as the 32-bit
build from the LiveCD installed to a partition.
It is what it is ... I had hoped and fully expected 64-bit building to be a
little faster. 068-GCC took almost 9.5 minutes longer on the 64-bit build
(54:37 vs 64:02 minutes) by itself. Riddle me that, Batman.
Note that the disk space usage between this run and the 64-bit run are fairly
close ... 64-bit using somewhat more ... but my earlier 32-bit run showed
much greater usage ... seems like something is broken now or was before.
For reference, here is the data from the 64-bit build.
for 64 bit build excluding grub and no kernel build
---------------------------------------------------
Book version is: SVN-x86_64-20070725
Using logs/028-binutils-pass1 to obtain the SBU unit value.
The SBU unit value is equal to 169.741 seconds.
Total time required to build the systen: 73.876 SBU
Total Installed files disk usage
(including /tools but not /sources): 610256 KB or 595.96 MB
(209 minutes)
Jeremy, I'm not trying to rain on your parade ... I want to figure out if I am
doing something wrong or if we are building incorrectly ... or if gcc is (you
fill in the blank).
Bummer,
K
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