[OE-core] Results for xz compression with different -T and and -e

[Andrei Gherzan]

On Thu, Jul 12, 2012 at 7:19 PM, Koen Kooi <koen at dominion.thruhere.net>wrote:

>
> Op 12 jul. 2012, om 17:51 heeft Andrei Gherzan het volgende geschreven:
>
> > On Thu, Jul 12, 2012 at 6:40 PM, Koen Kooi <koen at dominion.thruhere.net>
> wrote:
> >
> >
> > Op 12 jul. 2012 om 17:29 heeft Andrei Gherzan <andrei at gherzan.ro> het
> volgende geschreven:
> >
> > > Hello,
> > >
> > > Koen suggested to add -T to xz commands. We have this option
> implemented in our current version .1alpha.
> > >
> > > -T threads, --threads=threads
> > >               Specify the number of worker threads to use.  Setting
> threads to
> > >               a special value 0 makes xz use as many threads as there
> are  CPU
> > >               cores  on  the system.  The actual number of threads can
> be less
> > >               than threads if the input file is not big enough  for
>  threading
> > >               with  the  given  settings or if using more threads
> would exceed
> > >               the memory usage limit.
> > >
> > > -------------------
> > >
> > > Memory: 7.8 GiB
> > > Processor:: Intel® Core™ i5-2540M CPU @ 2.60GHz × 4
> > >
> > > File to compress: 1.9G
> > >
> > > xz -f -k -e -9 --check=crc32 (current configuration)
> > > Memory: 673Mb
> > > real    6m37.170s
> > > user    6m35.389s
> > > sys     0m0.884s
> > > Compressed file size: 3.4Mb
> > >
> > > xz -f -k -e -9 -T 4 --check=crc32
> > > Memory: Cannot allocate memory
> > >
> > > xz -f -k -e -8 -T 4 --check=crc32
> > > Memory: 1.8G
> > > real    3m24.462s
> > > user    12m8.502s
> > > sys     0m2.180s
> > > Compressed file size: 3.4Mb
> > >
> > > xz -f -k -T 4 --check=crc32 (-e defaults to -6)
> > > Memory: 471Mb
> > > real    1m9.265s
> > > user    4m8.972s
> > > sys     0m0.944s
> > > Compressed file size: 3.4Mb
> > >
> > > So my conclusion would be to use the default -e -6 with -T 4.
> >
> > Out of curiousity, what does -T0 give you?
> >
> >
> > Exactly the same as -T 0.
>
> I don't see that in the results above :)


Sorry. Wanted to type -T 4. :)
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openembedded.org/pipermail/openembedded-core/attachments/20120712/f71efb72/attachment-0002.html>