[OE-core] [PATCH 0/3] Fix xz compression command and optimize compression time

[Koen Kooi]

Any volunteers to test this on a system with >4 real cores? 

Op 12 jul. 2012, om 20:13 heeft Andrei Gherzan het volgende geschreven:

> 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(-)
> 
> -- 
> 1.7.9.5
>