On Tue, Apr 07, 2015 at 10:29:14AM -0600, Gary Thomas wrote:
> On 2015-04-07 10:19, Martin Jansa wrote:
> > On Tue, Apr 07, 2015 at 08:52:36AM -0600, Gary Thomas wrote:
> >> I'm building for multiple ARM i.MX6 platforms.  These have
> >> the same SoC, but slightly different peripherals. As far as
> >> I can tell, they should be able to share everything except
> >> for a few ${MACHINE} specific packages, e.g. the kernel and
> >> u-boot.
> >>
> >> Sadly, that doesn't seem to be the case.  The architecture
> >> specific packages are being split into two categories - plain
> >> ARM/Cortex-A9 and those that have i.MX6 specific optimizations.
> >> For example, after building a complete image (on the order of
> >> core-image-sato), I have this split:
> >> $ ls tmp/work/cortexa9hf-vfp-neon-amltd-linux-gnueabi/
> >> acl                  gst-player                 libsamplerate0         modutils-initscripts  shadow-sysroot
> >> alsa-utils           gst-plugins-bad            libsm                  mpeg2dec              shared-mime-info
> >> apmd                 gst-plugins-good           libsndfile1            mplayer2              speex
> >> atk                  gst-plugins-ugly           libsoup-2.4            mtdev                 sqlite3
> >> attr                 gstreamer                  libtheora              ncurses               startup-notification
> >> base-passwd          gstreamer1.0               libtirpc               neon                  strace
> >>      ...
> >> gst-ffmpeg           libpostproc                matchbox-wm            scrnsaverproto        zlib
> >> gst-fluendo-mpegmux  libproxy                   mkfontdir              settings-daemon
> >> gst-meta-base        libpthread-stubs           mkfontscale            shadow
> >>
> >> $ ls tmp/work/cortexa9hf-vfp-neon-mx6qdl-amltd-linux-gnueabi/
> >> alsa-lib      gst-plugins-base           imx-gpu-viv  libfslparser   libsdl      xf86-video-imxfb-vivante
> >> cairo         gstreamer1.0-plugins-bad   libdrm       libfslvpuwrap  mesa        xserver-xorg
> >> firmware-imx  gstreamer1.0-plugins-base  libfslcodec  libglu         pulseaudio
> >>
> >> It's the second category that is causing problems.  They do not
> >> seem to end up in any shareable sstate at all.  If I try to rebuild
> >> using only sstate, i.e. build my complete image to success, then
> >> remove 'tmp' and rebuild, using the sstate-cache from the first go,
> >> all of the above packages (alsa-lib, ..., xserver-xorg) are all
> >> rebuilt from scratch.  Those recipes do seem to end in my sstate-cache,
> >> but they are never reused from it.
> >>
> >> What would make this happen?  How can I prevent it?
> >>
> >> As is, sstate is not really shareable between these i.MX6 targets
> >> as so much is being rebuilt all the time...
> >>
> >> Any ideas or pointers gladly welcomed.
> >
> > Try openembedded-core/scripts/sstate-diff-machines.sh
> > to see why.
> >
> 
> Can this work if I build for the two machines in separate trees?

Yes, you can generate the report in each tree separately and then
compare them in one of them.

> Also, I'm really trying to find out why a build for the same machine
> doesn't reuse sstate, in the same build tree, back-to-back builds
> (no metadata changes)

Sorry, is "the same build tree" something else than "the two machines in
separate trees" or are you testing both?

-- 
Martin 'JaMa' Jansa     jabber: Martin.Jansa@gmail.com