On Thu, Sep 07, 2023 at 10:56:21AM +0200, Ahmad Fatoum wrote: > On 06.09.23 17:08, Jules Maselbas wrote: > > This change will select the arm64 BCJ filter for aarch64 instead of > > the arm filter which was always selected for arm based architectures. > > > > The selected filter is also tested, by looking if it is present in > > the long help message of xz, this is because the arm64 BCJ filter is > > a recent addition to xz. > > > > Signed-off-by: Jules Maselbas <jmaselbas@xxxxxxxx> > > How much of an improvement is BCJ=--arm over BCJ=""? In my case using the --arm BCJ on a aarch64 barebox is slightly worst than no BCJ at all. $ xz -vkf --check=crc32 --lzma2=dict=32MiB barebox.bin 100 % 84.7 KiB / 236.9 KiB = 0.357 $ xz -vkf --check=crc32 --arm --lzma2=dict=32MiB barebox.bin 100 % 85.5 KiB / 236.9 KiB = 0.361 $ xz -vkf --check=crc32 --arm64 --lzma2=dict=32MiB barebox.bin 100 % 81.0 KiB / 236.9 KiB = 0.342 > I wonder if we should fallback from --arm64 to --arm. > > Cheers, > Ahmad > > > --- > > scripts/xz_wrap.sh | 5 ++++- > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > diff --git a/scripts/xz_wrap.sh b/scripts/xz_wrap.sh > > index 7a2d372f48..5b5f3adcff 100755 > > --- a/scripts/xz_wrap.sh > > +++ b/scripts/xz_wrap.sh > > @@ -16,8 +16,11 @@ case $SRCARCH in > > x86) BCJ=--x86 ;; > > powerpc) BCJ=--powerpc ;; > > ia64) BCJ=--ia64; LZMA2OPTS=pb=4 ;; > > - arm) BCJ=--arm ;; > > + arm) BCJ=--arm$S64 ;; > > sparc) BCJ=--sparc ;; > > esac > > > > +# clear BCJ filter if unsupported > > +xz -H | grep -q -- $BCJ || BCJ= > > + > > exec xz --check=crc32 $BCJ --lzma2=$LZMA2OPTS,dict=32MiB > > -- > Pengutronix e.K. | | > Steuerwalder Str. 21 | http://www.pengutronix.de/ | > 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | > Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | >
