[OE-core] qemuarm: should it really have TUNE_ARCH armv5te?
Martin Jansa
martin.jansa at gmail.com
Fri Sep 21 15:52:38 UTC 2012
On Sat, Sep 15, 2012 at 09:01:42AM +0200, Martin Jansa wrote:
> On Thu, Sep 13, 2012 at 01:58:31PM +0100, Richard Purdie wrote:
> > On Thu, 2012-09-13 at 14:14 +0200, Martin Jansa wrote:
> > > On Thu, Sep 13, 2012 at 11:42:06AM +0100, Richard Purdie wrote:
> > > > On Thu, 2012-09-13 at 08:20 +0200, Martin Jansa wrote:
> > > > > On Wed, Sep 12, 2012 at 03:33:03PM +0100, Richard Purdie wrote:
> > > > > > On Tue, 2012-09-11 at 15:01 +0200, Martin Jansa wrote:
> > > > > > > Hi,
> > > > > > >
> > > > > > > when building spitz and qemuarm (both produces packages in armv5te feed)
> > > > > > > resulting packages are tuned with -mtune=xscale (when built for spitz)
> > > > > > > or -mtune=arm926ej-s (when built for qemuarm).
> > > > > > >
> > > > > > > From
> > > > > > > https://bugzilla.yoctoproject.org/show_bug.cgi?id=1916#c5
> > > > > > > Firstly, if you go changing the tune parameters in a given machine,
> > > > > > > you are expected to use a different PACKAGE_ARCH. If you do that, you
> > > > > > > will get a different package feed for the different binaries,
> > > > > > > different WORKDIR and so on. This was always the way the package
> > > > > > > architectures was intended to work and nothing has changed there. Yes,
> > > > > > > you as the user changing various variables can create inconsistent
> > > > > > > package feeds. There are 101 ways you can do that, the simple answer
> > > > > > > is just don't. We're therefore unlikely to add MACHINE to DEPLOY_DIR
> > > > > > > or remove PACKAGE_ARCH, please just use it as its intended.
> > > > > > >
> > > > > > > Does qemuarm use oe-core as it's intended?
> > > > > > >
> > > > > > > Shouldn't spitz produce something like armv5te-xscale and qemuarm armv5te-arm926ejs?
> > > > > > > It would cause all recipes to build again (cannot share armv5te feed anymore),
> > > > > > > but at least it would build it and user will really get it on target, right now
> > > > > > > opkg upgrade can download some packages with xscale some with arm926ej-s.
> > > > > > >
> > > > > > > $ ~/bitbake/bin/bitbake-diffsigs
> > > > > > > stamps.1347348910/spitz/armv5te-oe-linux-gnueabi/linux-libc-headers-3.4.3-r0.do_configure.sigdata.04b364a15889fcff7502614f1c116abc
> > > > > > > stamps.1347348910/qemuarm/armv5te-oe-linux-gnueabi/linux-libc-headers-3.4.3-r0.do_configure.sigdata.656f0583be969b427f040f2e143bcb14
> > > > > > > basehash changed from 7fe9c0a3455dac20ba6a90ed337b097e to d8dd2ff8613d0aafe60bef1a1e9469a1
> > > > > > > Variable TUNE_CCARGS value changed from
> > > > > > > ${@bb.utils.contains("TUNE_FEATURES", "armv5", "-march=armv5${ARMPKGSFX_THUMB}${ARMPKGSFX_DSP}", "", d)}
> > > > > > > ${@bb.utils.contains("TUNE_FEATURES", "armv4", "-march=armv4${ARMPKGSFX_THUMB}", "", d)}
> > > > > > > ${@bb.utils.contains("TUNE_FEATURES", "thumb", "${ARM_THUMB_M_OPT}", "", d)}
> > > > > > > ${@bb.utils.contains("TUNE_FEATURES", "no-thumb-interwork", "-mno-thumb-interwork", "-mthumb-interwork", d)}
> > > > > > > ${@bb.utils.contains("TUNE_FEATURES", "vfp", bb.utils.contains("TUNE_FEATURES", "callconvention-hard", "-mfloat-abi=hard", "-mfloat-abi=softfp", d), "" ,d)}
> > > > > > > ${@bb.utils.contains("TUNE_FEATURES", "xscale", "-mtune=xscale", "", d)}
> > > > > > > to
> > > > > > > ${@bb.utils.contains("TUNE_FEATURES", "armv5", "-march=armv5${ARMPKGSFX_THUMB}${ARMPKGSFX_DSP}", "", d)}
> > > > > > > ${@bb.utils.contains("TUNE_FEATURES", "armv4", "-march=armv4${ARMPKGSFX_THUMB}", "", d)}
> > > > > > > ${@bb.utils.contains("TUNE_FEATURES", "thumb", "${ARM_THUMB_M_OPT}", "", d)}
> > > > > > > ${@bb.utils.contains("TUNE_FEATURES", "no-thumb-interwork", "-mno-thumb-interwork", "-mthumb-interwork", d)}
> > > > > > > ${@bb.utils.contains("TUNE_FEATURES", "vfp", bb.utils.contains("TUNE_FEATURES", "callconvention-hard", "-mfloat-abi=hard", "-mfloat-abi=softfp", d), "" ,d)}
> > > > > > > ${@bb.utils.contains("TUNE_FEATURES", "arm926ejs", "-mtune=arm926ej-s", "", d)}
> > > > > > >
> > > > > >
> > > > > > This is a tricky one. As others have mentioned, this is a tune
> > > > > > parameter, not an arch one and as such the binaries are compatible with
> > > > > > each other although they potentially are compiled differently with
> > > > > > different optimisations.
> > > > > >
> > > > > > As such, mixing the feeds is permitted and will not cause any real world
> > > > > > usage problem. As you point out, sstate is much more sensitive to this
> > > > > > kind of change and is correctly deciding the output is different though.
> > > > > >
> > > > > > I think my preferred approach would be to have the tune files do
> > > > > > something like:
> > > > > >
> > > > > > -mtune=${ARMV5TEDEFAULTTUNE}
> > > > > >
> > > > > > and then the user can set ARMV5DEFAULTTUNE to whatever the believe is a
> > > > > > appropriate. This would result in the package feed at least having a
> > > > > > consistent state of one tune and sstate would be happy. It then becomes
> > > > > > a distro policy decision which is what it should be. ARMV5TEDEFAULTTUNE
> > > > > > would default to the current values meaning the distro would then just
> > > > > > do:
> > > > > >
> > > > > > ARMV5TEDEFAULTTUNE_poky = "xscale"
> > > > > >
> > > > > > and hence make their decision. Of course the distro could also decide to
> > > > > > split the package architectures up which is equally fine.
> > > > > >
> > > > > > Does something like that sound like it would work?
> > > > >
> > > > > My solution seems to be a bit more flexible then this.
> > > >
> > > > Which cases does it enable which the above doesn't?
> > >
> > > To have separate binary feeds for some packages while keeping most of
> > > other packages in armv5te feed without any -mtune or with some
> > > ARMV5TEDEFAULTTUNE.
> >
> > Firstly, lets clearly define what the problems are. We want to have some
> > packages with the existing tune in separate feeds and have other
> > packages sharing (or have no) mtune values?
>
> The proble is, that tune-cpu.inc files sets different -mcpu while
> keeping the same PACKAGE_ARCH (first commit in my brach)
>
> > The reason I say that is that initially this looked like a problem with
> > sstate and the specific mtune values which is a relatively generic and
> > widespread issue. The problem described above is implementation of what
> > is very specific distro policy. I want to be clear about which
> > problem(s) we're solving as that is leading to confusion discussing it.
>
> sstate is "correctly" detecting -mcpu change and rebuild all packages
> with new mcpu, but resulting ipk are in the same arch -> user wont see
> which -mcpu was used to buld particular .ipk.
>
> > If the problem(s) we're solving are the distro feed one rather than
> > sstate, the problem is more specific the distro policy and I'd expect
> > the distro itself to be handling this and not the core.
>
> If I add those PACKAGE_ARCH setting to each tune* which sets new
> DEFAULTUNE them some distributions can see it as regression as e.g.
> xscale and arm926ejs feed will need twice as much space as now shared
> armv5te.
>
> Removin tune-cpu from machine config also seems bad, because of loosing
> the option to use correct -mcpu.
>
> That's my solution keeps all information "local" in tune file
> DEFAULTTUNE will be set to generic arm5te
> OPTDEFAULTTUN to xscale
>
> and distro then can choose which one to use by default or for some
> packages.. see my e-mail about it (I won't write it again because I'm
> writting from phone)
Even with last version of jansa/tune it does not really help with
rebuilds
$ bitbake-diffsigs stamps.1348241943/*/armv5te-oe-linux-gnueabi/linux-libc-headers-3.4.3-r0.do_configure*
basehash changed from 82dd3229952508550532e9ab37e78dc4 to 1d04ba204fe9afb1d346156dc066da93
Variable TUNE_CCARGS value changed from
${@bb.utils.contains("TUNE_FEATURES", "armv5", "-march=armv5${ARMPKGSFX_THUMB}${ARMPKGSFX_DSP}", "", d)}
${@bb.utils.contains("TUNE_FEATURES", "armv4", "-march=armv4${ARMPKGSFX_THUMB}", "", d)}
${@bb.utils.contains("TUNE_FEATURES", "thumb", "${ARM_THUMB_M_OPT}", "", d)}
${@bb.utils.contains("TUNE_FEATURES", "no-thumb-interwork", "-mno-thumb-interwork", "-mthumb-interwork", d)}
${@bb.utils.contains("TUNE_FEATURES", "vfp", bb.utils.contains("TUNE_FEATURES", "callconvention-hard", "-mfloat-abi=hard", "-mfloat-abi=softfp", d), "" ,d)}
${@bb.utils.contains("TUNE_FEATURES", "arm926ejs", "-mtune=arm926ej-s", "", d)}
to
${@bb.utils.contains("TUNE_FEATURES", "armv5", "-march=armv5${ARMPKGSFX_THUMB}${ARMPKGSFX_DSP}", "", d)}
${@bb.utils.contains("TUNE_FEATURES", "armv4", "-march=armv4${ARMPKGSFX_THUMB}", "", d)}
${@bb.utils.contains("TUNE_FEATURES", "thumb", "${ARM_THUMB_M_OPT}", "", d)}
${@bb.utils.contains("TUNE_FEATURES", "no-thumb-interwork", "-mno-thumb-interwork", "-mthumb-interwork", d)}
${@bb.utils.contains("TUNE_FEATURES", "vfp", bb.utils.contains("TUNE_FEATURES", "callconvention-hard", "-mfloat-abi=hard", "-mfloat-abi=softfp", d), "" ,d)}
${@bb.utils.contains("TUNE_FEATURES", "xscale", "-mtune=xscale", "", d)}
Hash for dependent task linux-libc-headers_3.4.3.bb.do_patch changed from 4d1f46fa912bc21421d343811acab517 to 663e25ca238e049eaff02fd288c5342e
So even if I let both machines using only armv5 thumb dsp TUNE_FEATURES it still
rebuilds e.g. linux-libc-headers.
We can merge all those
TUNE_CCARGS += "${@bb.utils.contains("TUNE_FEATURES", "xscale", "-mtune=xscale", "", d)}"
fragmets to arch-armv5-dsp.inc, but that doesn't look very correct too (imagine someone who
wants to add new tune-magicfoo in his BSP which adds another possible value for TUNE_FEATURES
but still uses armv5te feed.
Any idea?
Cheers,
>
> > > But -mtune=${ARMV5TEDEFAULTTUNE} in tune-arm926ejs.inc with
> > > xscale value set through ARMV5TEDEFAULTTUNE_disto doesn't look very
> > > intuitive.
> >
> > I'm not saying that it is. What I'm saying is that it puts the pain in
> > the place of the person trying to do the deep configuration and isn't
> > the first thing a new user hits and struggles with.
> >
> > We can add variables for *everything*. That doesn't mean that we should
> > and this is one case that I think the proposal complicates something
> > that is already too complicated, badly (under) documented and being
> > misused (see the number of patches I've seen recently abusing
> > DEFAULTTUNE).
> >
> > At least if the tune files and system was well documented I might feel
> > better about things but right now it isn't.
> >
> > > And how many .*DEFAUTTUNE variables distro should set?
> >
> > As soon as you enter the world of recipe specific tunings, I suspect a
> > number of variables are going to need to get set.
> >
> > Cheers,
> >
> > Richard
> >
>
> --
> Martin 'JaMa' Jansa jabber: Martin.Jansa at gmail.com
--
Martin 'JaMa' Jansa jabber: Martin.Jansa at gmail.com
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