Re: [PATCH 0/3] Fix xz compression command and optimize compression time

[Saul Wold <sgw@linux.intel.com>]

On 07/12/2012 11:13 AM, Andrei Gherzan wrote:
> 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 0.
>
> The following changes since commit 90ad663909c0c8a405b22a510c9f957007d02669:
>
>    upstream_tracking: update boost (2012-07-09 17:21:38 +0100)
>
> are available in the git repository at:
>
>    git://git.yoctoproject.org/poky-contrib ag/xz
>    http://git.yoctoproject.org/cgit.cgi/poky-contrib/log/?h=ag/xz
>
> Andrei Gherzan (3):
>    image_types.bbclass: Fix COMPRESS_CMD for xz to redirect compressed
>      data to file
>    image_types.bbclass: Add XZ variable to set number of threads to be
>      used while compressing
>    image_types.bbclass: Default XZ_COMPRESSION_LEVEL to -e -6
>
>   meta/classes/image_types.bbclass |    5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
>

Merged into OE-Core

Thanks
	Sau!