[yocto] sstate black hole?

[Gary Thomas]

On 2015-04-07 10:33, Martin Jansa wrote:
> 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?
>

Both actually, but at the moment the most interesting problem
is for a given machine that sstate is not being [re]used for
these recipes.

-- 
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Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
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