On Thu, Jun 30, 2016 at 03:13:58PM +0100, Daniel P. Berrange wrote:
On Thu, Jun 30, 2016 at 04:10:01PM +0200, Martin Kletzander wrote:
This almost reverts b7200d723648. The size is increased from 11M to 13M and the compression is sped up from 2 minutes to 17 seconds.
At the expense of download and decompression time.
The compression level is removed because -9 doesn't allow multiple threads to be spawned. Effectively speeds up distcheck as well.
1) For distcheck, any level over 1 is a waste of time, since we're throwing it away. 2) For regular libvirt distribution, any time spent compressing results in greater overall time savings, because the file is downloaded and decompressed many times. So, should we keep moderate defaults here, with anyone wantintg to do 1) or 2) properly supplying their own XZ_OPT? Or create a different set of targets with lower compression settings for development purposes (e.g. quick-distcheck, quick-rpm).
ACK, the space saving over .gz is already massive, so 11 vs 13 MB is nothing.
The xz man page recommends against using -9 in general anyway
That is due to the memory constraints, so it transitively recommends against using libvirt :) Using -e is recommended to decrease file size by spending more CPU time at compression time without increasing the requirements for the decompressor. And a good idea to use when distributing software tarballs, which is why it is the automake default and it's what we were using before I touched it in b7200d723648.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com> --- Makefile.am | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/Makefile.am b/Makefile.am index 99ee4763c5cd..50c358c30d2c 100644 --- a/Makefile.am +++ b/Makefile.am @@ -22,7 +22,7 @@ GENHTML = genhtml SUBDIRS = . gnulib/lib include/libvirt src daemon tools docs gnulib/tests \ tests po examples
-XZ_OPT ?= -9ev +XZ_OPT ?= -v -T0 export XZ_OPT
ACLOCAL_AMFLAGS = -I m4
NACK * this removes -e form the default distribution, which is worse than what we had before b7200d723648 and unsafe for the freeze * slow 'make distcheck' is not a user-visible bug. Jan