Re: [fedora-arm] arm software floating point support going forward

2013-02-02 Thread Peter Robinson
On Fri, Feb 1, 2013 at 4:20 PM, Derek Atkins  wrote:
> Jon,
>
> Thanks for the reply.  I certainly don't have the hardware to host a v5
> koji.  All I own are 2 Sheevas and 2 Gurus (and not even the "Server
> Plus" models).  Moreover, one of my Sheevas is in "critical" production
> on my network so I can't really pull it away to perform other duties.
>
> I was actually looking at a Cubieboard to get some newer, more powerful
> hardware, because the Guru is way too low powered to run my MySQL
> instance.  I may even find that the Cubie is too low-powered, but
> obviously cannot test that until I have one or have access to one.
> Regardless, right now I don't have the budget to acquire new hardware,
> which is why I'd like to continue using what I already own.
>
> Not being intimately familiar with the various changes in the hardware I
> guess I just don't understand why we need so many target-specific
> distributions?  I thought the only issue was the floating point ABI
> issue, which would lead me to believe that we only would need two, FP
> and non-FP?  Is there really a significant speed improvement with
> e.g. v7 or v8 when compiled specifically vs. running e.g. v6 on a v7 or
> v8?  ISTR that measurements showed some but relatively insignificant
> speed differences, so why not just stay at the lowest level to support
> more hardware?

Basically ARMv7 is the current generation of chipsets. ARMv5 and ARMv6
is basically dead. ARMv5 SoCs are end of line in ARM and as they
require things like DDR1 they are getting expensive for manufacturers
to produce so available hardware is dwindling. They also only support
a max of 1gb of ram and are limited. ARM is moving all the remaining
users of v5 onto platforms like Cortex-A5 chips that use more modern
memory and are cheaper to produce.

There have never been that many ARMv5 platforms suitable to running
fedora with the kirkwood plugs basically being it, the HW isn't that
capable and availability will only shink with time. It's not an
insignificant amount of effort to support this platform. I think I as
the person that basically does all the kernel maintenance and all the
building of packages and the vast majority of fixing of the
problematic packages or chasing people to fix them I think I'm one of
the few that is able to quantify this time and effort.

To go with that there's frankly not a lot of people actually bothering
to test armv5 and this is categorised with the fact that some core
packages and functionality were broken in F-18 for quite some time and
not even reported so issues like that helped us make up our mind
whether it was critical to test.

F-17 download numbers I don't believe were large.

Ultimately we need to assess where our efforts are best directed to
get our best bang for our buck. Most of those that are doing
significant work on the platform are volunteers. The fact is that
while it is sad for us to be dropping the support I don't believe it's
the best way for those people that are doing their work for them to
invest their time for a platform that ARM themselves is dead with
limited machines available now and their availability in new products
moving forward it's basically extinct.

Regards,
Peter
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Re: [fedora-arm] arm software floating point support going forward

2013-02-01 Thread Derek Atkins
Jon,

Thanks for the reply.  I certainly don't have the hardware to host a v5
koji.  All I own are 2 Sheevas and 2 Gurus (and not even the "Server
Plus" models).  Moreover, one of my Sheevas is in "critical" production
on my network so I can't really pull it away to perform other duties.

I was actually looking at a Cubieboard to get some newer, more powerful
hardware, because the Guru is way too low powered to run my MySQL
instance.  I may even find that the Cubie is too low-powered, but
obviously cannot test that until I have one or have access to one.
Regardless, right now I don't have the budget to acquire new hardware,
which is why I'd like to continue using what I already own.

Not being intimately familiar with the various changes in the hardware I
guess I just don't understand why we need so many target-specific
distributions?  I thought the only issue was the floating point ABI
issue, which would lead me to believe that we only would need two, FP
and non-FP?  Is there really a significant speed improvement with
e.g. v7 or v8 when compiled specifically vs. running e.g. v6 on a v7 or
v8?  ISTR that measurements showed some but relatively insignificant
speed differences, so why not just stay at the lowest level to support
more hardware?

Thanks,

-derek

Jon Masters  writes:

> Derek,
>
> It is less "powers that be" than a collaborative effort/decision. We do not 
> have resources to justify keeping v5 alive but you are free to coordinate 
> with others and pick it up, in the same way that Seneca are to own v6 support 
> (maybe Seneca can even help with build system setup if you ask them). Do you 
> have any interest in driving that?
>
> You will find the ominous powers that be are in fact a bunch of us doing the 
> work who are overloaded enough to keep just v7 and v8 on track :) For those 
> who are devastated and have no v7 hardware, ping me off list and maybe I can 
> look into getting a couple of v7 boards out there.
>
> Jon.
> -- 
> Sent from my phone. Please excuse brevity.
>
> Derek Atkins  wrote:
>
> Quentin Armitage  writes:
>
>> since there has been no major objection i will disable building
>> armv5tel rpms in rawhide before the mass rebuild.
>> 
>> Dennis
>> 
>> I guess it's too late now, but I got a few days behind on my list emails. I
>> use 2 * Sheevaplugs and 2 * Dreamplugs with Fedora, and would be very
>> disappointed to see support for them being dropped from Fedora. For me, I
>> still see quite a lifetime in them for what they are doing.
>
> I've mentioned multiple times my hope to keep kirkwood support in
> Fedora, but alas it feels like the powers that be just don't care about
> us *plug users.  :(   If I want to continue using my plugs I guess I'll
> have to learn Debuntu.  :(
>
>> Quentin Armitage
>
> -derek

-- 
   Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory
   Member, MIT Student Information Processing Board  (SIPB)
   URL: http://web.mit.edu/warlord/PP-ASEL-IA N1NWH
   warl...@mit.eduPGP key available
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Re: [fedora-arm] arm software floating point support going forward

2013-02-01 Thread Jon Masters
Derek,

It is less "powers that be" than a collaborative effort/decision. We do not 
have resources to justify keeping v5 alive but you are free to coordinate with 
others and pick it up, in the same way that Seneca are to own v6 support (maybe 
Seneca can even help with build system setup if you ask them). Do you have any 
interest in driving that?

You will find the ominous powers that be are in fact a bunch of us doing the 
work who are overloaded enough to keep just v7 and v8 on track :) For those who 
are devastated and have no v7 hardware, ping me off list and maybe I can look 
into getting a couple of v7 boards out there.

Jon.
-- 
Sent from my phone. Please excuse brevity.

Derek Atkins  wrote:

Quentin Armitage  writes:

> since there has been no major objection i will disable building
> armv5tel rpms in rawhide before the mass rebuild.
> 
> Dennis
> 
> I guess it's too late now, but I got a few days behind on my list emails. I
> use 2 * Sheevaplugs and 2 * Dreamplugs with Fedora, and would be very
> disappointed to see support for them being dropped from Fedora. For me, I
> still see quite a lifetime in them for what they are doing.

I've mentioned multiple times my hope to keep kirkwood support in
Fedora, but alas it feels like the powers that be just don't care about
us *plug users.  :(   If I want to continue using my plugs I guess I'll
have to learn Debuntu.  :(

> Quentin Armitage

-derek
-- 
   Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory
   Member, MIT Student Information Processing Board  (SIPB)
   URL: http://web.mit.edu/warlord/PP-ASEL-IA N1NWH
   warl...@mit.eduPGP key available
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Re: [fedora-arm] arm software floating point support going forward

2013-01-31 Thread Brendan Conoboy

On 01/31/2013 07:21 AM, Quentin Armitage wrote:

I guess it's too late now, but I got a few days behind on my list
emails. I use 2 * Sheevaplugs and 2 * Dreamplugs with Fedora, and would
be very disappointed to see support for them being dropped from Fedora.
For me, I still see quite a lifetime in them for what they are doing.


Remember the plugs will be supported throughout the F18 lifecycle, so 
you still have over a year of support.


Others are welcome to pick up the torch and run an armv5tel koji 
server/builds.  We're all volunteers on this project, pursuing our 
individual interests.  If v5 is yours, feel free to chip in.


--
Brendan Conoboy / Red Hat, Inc. / b...@redhat.com
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Re: [fedora-arm] arm software floating point support going forward

2013-01-31 Thread Till Maas
Hi,

On Thu, Jan 31, 2013 at 04:30:32PM +0100, Dan Horák wrote:

> Fedora provides all tools to run armv5tel as say tertiary architecture,
> just needs a volunteer with some hardware.

what is going to happen with the hardware used to build packages now for
kirkwood?

Regards
Till
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Re: [fedora-arm] arm software floating point support going forward

2013-01-31 Thread Derek Atkins
Quentin Armitage  writes:

> since there has been no major objection i will disable building
> armv5tel rpms in rawhide before the mass rebuild.
> 
> Dennis
> 
> I guess it's too late now, but I got a few days behind on my list emails. I
> use 2 * Sheevaplugs and 2 * Dreamplugs with Fedora, and would be very
> disappointed to see support for them being dropped from Fedora. For me, I
> still see quite a lifetime in them for what they are doing.

I've mentioned multiple times my hope to keep kirkwood support in
Fedora, but alas it feels like the powers that be just don't care about
us *plug users.  :(   If I want to continue using my plugs I guess I'll
have to learn Debuntu.  :(

> Quentin Armitage

-derek
-- 
   Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory
   Member, MIT Student Information Processing Board  (SIPB)
   URL: http://web.mit.edu/warlord/PP-ASEL-IA N1NWH
   warl...@mit.eduPGP key available
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Re: [fedora-arm] arm software floating point support going forward

2013-01-31 Thread Dan Horák
Quentin Armitage píše v Čt 31. 01. 2013 v 15:21 +: 
> On Mon, 2013-01-28 at 22:26 -0600, Dennis Gilmore wrote:
> 
> > El Fri, 25 Jan 2013 10:22:23 -0600
> > Dennis Gilmore  escribió:
> > > Hi all,
> > > 
> > > I wanted to kick off a discussion, I think that with the work that
> > > Seneca is doing for armv6hl to support the Raspberry Pi most of the
> > > need for building sfp has gone away. I would like us to drop support
> > > for sfp in F19 that means that anyone running a kirkwood based system
> > > would get supported software updates for approximately 13 months from
> > > now. with cubie boards and other devices coming around that are cheap
> > > and more powerful and similar options I think there is little benefit
> > > to continuing to support sfp.
> > > 
> > > Ive put in a request to get numbers of people using the arm and armhfp
> > > portions of mirrormanager to get some idea of the number of users out
> > > there, though i suspect most arm are raspberry pi and people building
> > > in mock.
> > 
> > since there has been no major objection i will disable building
> > armv5tel rpms in rawhide before the mass rebuild.
> > 
> > Dennis
> 
> I guess it's too late now, but I got a few days behind on my list
> emails. I use 2 * Sheevaplugs and 2 * Dreamplugs with Fedora, and would
> be very disappointed to see support for them being dropped from Fedora.
> For me, I still see quite a lifetime in them for what they are doing.

Fedora provides all tools to run armv5tel as say tertiary architecture,
just needs a volunteer with some hardware.


Dan


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Re: [fedora-arm] arm software floating point support going forward

2013-01-31 Thread Quentin Armitage
On Mon, 2013-01-28 at 22:26 -0600, Dennis Gilmore wrote:

> El Fri, 25 Jan 2013 10:22:23 -0600
> Dennis Gilmore  escribió:
> > Hi all,
> > 
> > I wanted to kick off a discussion, I think that with the work that
> > Seneca is doing for armv6hl to support the Raspberry Pi most of the
> > need for building sfp has gone away. I would like us to drop support
> > for sfp in F19 that means that anyone running a kirkwood based system
> > would get supported software updates for approximately 13 months from
> > now. with cubie boards and other devices coming around that are cheap
> > and more powerful and similar options I think there is little benefit
> > to continuing to support sfp.
> > 
> > Ive put in a request to get numbers of people using the arm and armhfp
> > portions of mirrormanager to get some idea of the number of users out
> > there, though i suspect most arm are raspberry pi and people building
> > in mock.
> 
> since there has been no major objection i will disable building
> armv5tel rpms in rawhide before the mass rebuild.
> 
> Dennis

I guess it's too late now, but I got a few days behind on my list
emails. I use 2 * Sheevaplugs and 2 * Dreamplugs with Fedora, and would
be very disappointed to see support for them being dropped from Fedora.
For me, I still see quite a lifetime in them for what they are doing.

Quentin Armitage

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Re: [fedora-arm] arm software floating point support going forward

2013-01-30 Thread Dennis Gilmore
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1

On Tue, 29 Jan 2013 16:13:33 -0600
Dennis Gilmore  wrote:

> -BEGIN PGP SIGNED MESSAGE-
> Hash: SHA1
> 
> El Mon, 28 Jan 2013 22:26:19 -0600
> Dennis Gilmore  escribió:
> > -BEGIN PGP SIGNED MESSAGE-
> > Hash: SHA1
> > 
> > El Fri, 25 Jan 2013 10:22:23 -0600
> > Dennis Gilmore  escribió:
> > > Hi all,
> > > 
> > > I wanted to kick off a discussion, I think that with the work that
> > > Seneca is doing for armv6hl to support the Raspberry Pi most of
> > > the need for building sfp has gone away. I would like us to drop
> > > support for sfp in F19 that means that anyone running a kirkwood
> > > based system would get supported software updates for
> > > approximately 13 months from now. with cubie boards and other
> > > devices coming around that are cheap and more powerful and
> > > similar options I think there is little benefit to continuing to
> > > support sfp.
> > > 
> > > Ive put in a request to get numbers of people using the arm and
> > > armhfp portions of mirrormanager to get some idea of the number of
> > > users out there, though i suspect most arm are raspberry pi and
> > > people building in mock.
> > 
> > since there has been no major objection i will disable building
> > armv5tel rpms in rawhide before the mass rebuild.
> 
> the next rawhide compose will be hfp only

now that we have had a hfp only compose ive disabled building armv5tel
rpms in koji for f19

Dennis
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Re: [fedora-arm] arm software floating point support going forward

2013-01-29 Thread Dennis Gilmore
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1

El Mon, 28 Jan 2013 22:26:19 -0600
Dennis Gilmore  escribió:
> -BEGIN PGP SIGNED MESSAGE-
> Hash: SHA1
> 
> El Fri, 25 Jan 2013 10:22:23 -0600
> Dennis Gilmore  escribió:
> > Hi all,
> > 
> > I wanted to kick off a discussion, I think that with the work that
> > Seneca is doing for armv6hl to support the Raspberry Pi most of the
> > need for building sfp has gone away. I would like us to drop support
> > for sfp in F19 that means that anyone running a kirkwood based
> > system would get supported software updates for approximately 13
> > months from now. with cubie boards and other devices coming around
> > that are cheap and more powerful and similar options I think there
> > is little benefit to continuing to support sfp.
> > 
> > Ive put in a request to get numbers of people using the arm and
> > armhfp portions of mirrormanager to get some idea of the number of
> > users out there, though i suspect most arm are raspberry pi and
> > people building in mock.
> 
> since there has been no major objection i will disable building
> armv5tel rpms in rawhide before the mass rebuild.

the next rawhide compose will be hfp only

Dennis
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Re: [fedora-arm] arm software floating point support going forward

2013-01-28 Thread Dennis Gilmore
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1

El Fri, 25 Jan 2013 10:22:23 -0600
Dennis Gilmore  escribió:
> Hi all,
> 
> I wanted to kick off a discussion, I think that with the work that
> Seneca is doing for armv6hl to support the Raspberry Pi most of the
> need for building sfp has gone away. I would like us to drop support
> for sfp in F19 that means that anyone running a kirkwood based system
> would get supported software updates for approximately 13 months from
> now. with cubie boards and other devices coming around that are cheap
> and more powerful and similar options I think there is little benefit
> to continuing to support sfp.
> 
> Ive put in a request to get numbers of people using the arm and armhfp
> portions of mirrormanager to get some idea of the number of users out
> there, though i suspect most arm are raspberry pi and people building
> in mock.

since there has been no major objection i will disable building
armv5tel rpms in rawhide before the mass rebuild.

Dennis
-BEGIN PGP SIGNATURE-
Version: GnuPG v2.0.19 (GNU/Linux)

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=SL8q
-END PGP SIGNATURE-
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Re: [fedora-arm] arm software floating point support going forward

2013-01-25 Thread Nicolas Pitre
On Fri, 25 Jan 2013, Josh Boyer wrote:

> On Fri, Jan 25, 2013 at 1:10 PM, Nicolas Pitre  wrote:
> > On Fri, 25 Jan 2013, Josh Boyer wrote:
> >
> >> On Fri, Jan 25, 2013 at 11:22 AM, Dennis Gilmore  wrote:
> >> > Hi all,
> >> >
> >> > I wanted to kick off a discussion, I think that with the work that
> >> > Seneca is doing for armv6hl to support the Raspberry Pi most of the
> >> > need for building sfp has gone away. I would like us to drop support
> >> > for sfp in F19 that means that anyone running a kirkwood based system
> >> > would get supported software updates for approximately 13 months from
> >> > now. with cubie boards and other devices coming around that are cheap
> >> > and more powerful and similar options I think there is little benefit
> >> > to continuing to support sfp.
> >>
> >> I'm not overly familiar with arm, but from a kernel standpoint you might
> >> be able to enable floating point emulation. That would let you run the
> >> hardfp binaries on the boards without an FPU.
> >
> > No, you can't.
> 
> OK.
> 
> > The only FP emulation the ARM kernel provide is for the antique FPA
> > instruction set that almost never got implemented in hardware, except
> > for a few exceptions that Linux never supported anyway.
> 
> Ah.  See, that would be where I point back to me knowning almost nothing
> about ARM ;).
> 
> > All modern EABI compliant binaries are using the VFP instruction set,
> > and the only thing the kernel implements is the processing of
> > exceptions for them.  To have a full VFP emulation support in the
> > kernel, significant development effort would be needed.
> 
> I find this slightly interesting to be honest.  In the embedded powerpc
> world, math emulation is used as a last ditch effort but it does exist.
> I would have thought the proliferation of ARM devices would generate some
> amount of interest in getting similar support in-kernel, but apparently
> not.

Thing is: a soft float library in user space is 8 to 25 times faster 
than any kernel emulation of machine FP instructions.  I know that 
as I wrote that soft-float library myself.  ;-)

Before EABI, it was common to have user space binaryes compiled for FPA 
and those instructions were always emulated by the kernel, since, as I 
said, there were no actual FPA hardware that Linux supported.

When EABI was introduced, it was decided to go with the soft-float 
library given the ABI was different anyway and performances were much 
better than any emulation.

That was before VFP became a reality.  With VFP hardware you then had 
the ability to still use the same procedure call convention but the 
ability to implement the intra procedure code using actual VFP 
instructions.  That is what most ARMv6+ binary distributions did prior 
the HF variant to remain compatible with the soft-float ABI.

But given that hardware VFP is now prevalent, going with full FP even at 
the function call level was implemented and deployed.



Nicolas
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Re: [fedora-arm] arm software floating point support going forward

2013-01-25 Thread Josh Boyer
On Fri, Jan 25, 2013 at 1:10 PM, Nicolas Pitre  wrote:
> On Fri, 25 Jan 2013, Josh Boyer wrote:
>
>> On Fri, Jan 25, 2013 at 11:22 AM, Dennis Gilmore  wrote:
>> > Hi all,
>> >
>> > I wanted to kick off a discussion, I think that with the work that
>> > Seneca is doing for armv6hl to support the Raspberry Pi most of the
>> > need for building sfp has gone away. I would like us to drop support
>> > for sfp in F19 that means that anyone running a kirkwood based system
>> > would get supported software updates for approximately 13 months from
>> > now. with cubie boards and other devices coming around that are cheap
>> > and more powerful and similar options I think there is little benefit
>> > to continuing to support sfp.
>>
>> I'm not overly familiar with arm, but from a kernel standpoint you might
>> be able to enable floating point emulation. That would let you run the
>> hardfp binaries on the boards without an FPU.
>
> No, you can't.

OK.

> The only FP emulation the ARM kernel provide is for the antique FPA
> instruction set that almost never got implemented in hardware, except
> for a few exceptions that Linux never supported anyway.

Ah.  See, that would be where I point back to me knowning almost nothing
about ARM ;).

> All modern EABI compliant binaries are using the VFP instruction set,
> and the only thing the kernel implements is the processing of
> exceptions for them.  To have a full VFP emulation support in the
> kernel, significant development effort would be needed.

I find this slightly interesting to be honest.  In the embedded powerpc
world, math emulation is used as a last ditch effort but it does exist.
I would have thought the proliferation of ARM devices would generate some
amount of interest in getting similar support in-kernel, but apparently
not.

Anyway, I'm not opposed to dropping a kernel variant at all.  Makes some
things simpler.

josh
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Re: [fedora-arm] arm software floating point support going forward

2013-01-25 Thread Nicolas Pitre
On Fri, 25 Jan 2013, Josh Boyer wrote:

> On Fri, Jan 25, 2013 at 11:22 AM, Dennis Gilmore  wrote:
> > Hi all,
> >
> > I wanted to kick off a discussion, I think that with the work that
> > Seneca is doing for armv6hl to support the Raspberry Pi most of the
> > need for building sfp has gone away. I would like us to drop support
> > for sfp in F19 that means that anyone running a kirkwood based system
> > would get supported software updates for approximately 13 months from
> > now. with cubie boards and other devices coming around that are cheap
> > and more powerful and similar options I think there is little benefit
> > to continuing to support sfp.
> 
> I'm not overly familiar with arm, but from a kernel standpoint you might
> be able to enable floating point emulation. That would let you run the
> hardfp binaries on the boards without an FPU.

No, you can't.

The only FP emulation the ARM kernel provide is for the antique FPA 
instruction set that almost never got implemented in hardware, except 
for a few exceptions that Linux never supported anyway.

All modern EABI compliant binaries are using the VFP instruction set, 
and the only thing the kernel implements is the processing of 
exceptions for them.  To have a full VFP emulation support in the 
kernel, significant development effort would be needed.


Nicolas
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Re: [fedora-arm] arm software floating point support going forward

2013-01-25 Thread Sean Omalley
I have a lot of kirkwood, a pi, no armv7, and no $$ atm so Im not anxious to 
have support dropped. :) I do understand the dilemma..:) I think kirkwood is 
about the only popular armv5tel but there are other 926 chips running around, 
and the Cortex A5 only has an optional FPU. 

The part of the atomics issues are solved with libatomic which is part of the 
gcc 4.8, and there is something available to 4.7 as well but it isn't built in, 
you have to link it in. It is essentially a generic atomic functions, for cases 
where real atomics aren't available or fully supported and an attempt at 
helping make them more generically supported. 

I was unable to rebuild gcc from the srpm which stimied a few relevent tests. 

I was actually wondering if multi-lib support between the armv5tej and the 
armv6 might be possible?? Then you have a hard/soft float distribution for 
thumb1 and still can do tricks with jazelle. Then roll with armv7/armv8 as a 
multilib 64/32. 

For me, the kirkwood is faster for dev then the raspi is, and the problem with 
the raspi speed isn't all a Hard float issue. 

One thing that might be easier that would speed up the builders a bit might be 
to start precompiling the headers. The other would be to see if thumb1 is 
actually decently supported. I think you will see a bigger boost with thumb 
instructions then you will with hardfloat especially
given the io constraints on the raspi. 

thumb2 is actually much better supported and it actually makes more sense to 
test thumb2 on armv7l+. 

Does anyone know when the arch started supporting multiple thumb executions per 
clock? 

I =would= like to see a full set of packages compiled on all the supported 
platforms asap. Getting the kinks worked out is just going to help the whole 
process moving forward for everyone. 



- Original Message -
> From: Josh Boyer 
> To: Dennis Gilmore 
> Cc: arm@lists.fedoraproject.org
> Sent: Friday, January 25, 2013 12:18 PM
> Subject: Re: [fedora-arm] arm software floating point support going forward
> 
> On Fri, Jan 25, 2013 at 11:22 AM, Dennis Gilmore  wrote:
>>  Hi all,
>> 
>>  I wanted to kick off a discussion, I think that with the work that
>>  Seneca is doing for armv6hl to support the Raspberry Pi most of the
>>  need for building sfp has gone away. I would like us to drop support
>>  for sfp in F19 that means that anyone running a kirkwood based system
>>  would get supported software updates for approximately 13 months from
>>  now. with cubie boards and other devices coming around that are cheap
>>  and more powerful and similar options I think there is little benefit
>>  to continuing to support sfp.
> 
> I'm not overly familiar with arm, but from a kernel standpoint you might
> be able to enable floating point emulation. That would let you run the
> hardfp binaries on the boards without an FPU.  It would be a performance
> hit for things doing FP heavy computation, but you could continue
> supporting those boards that way.
> 
> josh
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Re: [fedora-arm] arm software floating point support going forward

2013-01-25 Thread Josh Boyer
On Fri, Jan 25, 2013 at 11:22 AM, Dennis Gilmore  wrote:
> Hi all,
>
> I wanted to kick off a discussion, I think that with the work that
> Seneca is doing for armv6hl to support the Raspberry Pi most of the
> need for building sfp has gone away. I would like us to drop support
> for sfp in F19 that means that anyone running a kirkwood based system
> would get supported software updates for approximately 13 months from
> now. with cubie boards and other devices coming around that are cheap
> and more powerful and similar options I think there is little benefit
> to continuing to support sfp.

I'm not overly familiar with arm, but from a kernel standpoint you might
be able to enable floating point emulation. That would let you run the
hardfp binaries on the boards without an FPU.  It would be a performance
hit for things doing FP heavy computation, but you could continue
supporting those boards that way.

josh
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Re: [fedora-arm] arm software floating point support going forward

2013-01-25 Thread Brendan Conoboy

On 01/25/2013 08:22 AM, Dennis Gilmore wrote:

Hi all,

I wanted to kick off a discussion, I think that with the work that
Seneca is doing for armv6hl to support the Raspberry Pi most of the
need for building sfp has gone away. I would like us to drop support
for sfp in F19 that means that anyone running a kirkwood based system
would get supported software updates for approximately 13 months from
now. with cubie boards and other devices coming around that are cheap
and more powerful and similar options I think there is little benefit
to continuing to support sfp.


I've been thinking the same thing.  This still gives people on kirkwood 
plugs over a year of active support, and Pi users will continue to have 
support via armv6hl.  Another added benefit is that this will free up 
rawhide build systems which can be used by other Fedora communities who 
want to run projects on the ARM boxes (COPR, infra, etc).



Ive put in a request to get numbers of people using the arm and armhfp
portions of mirrormanager to get some idea of the number of users out
there, though i suspect most arm are raspberry pi and people building
in mock.


That'll be some great information to have. It would be interesting to 
know Seneca's Pi download stats, too.


--
Brendan Conoboy / Red Hat, Inc. / b...@redhat.com
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Re: [fedora-arm] arm software floating point support going forward

2013-01-25 Thread Peter Robinson
On Fri, Jan 25, 2013 at 4:37 PM, Gordan Bobic  wrote:
> On Fri, 25 Jan 2013 10:22:23 -0600, Dennis Gilmore  wrote:
>>
>> Hi all,
>>
>> I wanted to kick off a discussion, I think that with the work that
>> Seneca is doing for armv6hl to support the Raspberry Pi most of the
>> need for building sfp has gone away. I would like us to drop support
>> for sfp in F19 that means that anyone running a kirkwood based system
>> would get supported software updates for approximately 13 months from
>> now. with cubie boards and other devices coming around that are cheap
>> and more powerful and similar options I think there is little benefit
>> to continuing to support sfp.
>>
>> Ive put in a request to get numbers of people using the arm and armhfp
>> portions of mirrormanager to get some idea of the number of users out
>> there, though i suspect most arm are raspberry pi and people building
>> in mock.
>
>
> I am inclined to agree.
>
> At the same time, however, this poses a few related questions?
>
> With essentially dropping armv5tel, does it make sense to replace
> it with what is very obviously going to be an arch with extremely
> short-lived support-worthyness? Or would it be better to just drop
> everything less than armv7hl and be done with it, and free up all
> the resources for focusing on the primary target?
>
> The focus question is particularly important considering that in
> the near future there will also be the 64-bit ARM arch to support.
>
> Or to put it another way - if armv5tel is drop-worthy, does
> what is essentially one device (the Pi) warrant the maintenance
> of an arch all by itself? If the answer to this is close to
> yes, then what about dropping armv7hl in favour of armv6hl as
> the only supported 32-bit ARM arch?

We're not really replacing it. There's currently 3 arches across 2
koji instances. armv5tel and armv7 are on the "official" Fedora ARM
secondary and the armv6hl is a project being run by Seneca. We'd be
dropping armv5tel from the "official" project leaving only armv7 there
with Seneca continuing to run the armv6hl project separately. armv6hl
won't be added to the "official" Fedora ARM secondary infra.

This is in preparation of promoting armv7 to a primary architecture at
which point the Fedora ARM secondary will remain around for the
lifecycle of F-17 - F-19 for building of updates. Once F-19 (or what
ever the last armv7 release of Fedora ARM is as a secondary arch) is
EOL that infra would be decommissioned. The armv6hl infra will remain
as long as Seneca and others believe it's worth time in maintaining.

> What is the performance gap, hardware being equal, between:
>
> armv5tel -> armv6hl
> armv6hl -> armv7hl
>
> The answer to that question seems like it ought to factor
> into any decision made.
>
> Do any of the long standing issues of armv5tel (atomics?) go
> away when using armv6hl?

Yes, atomics is supported on armv6hl.
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Re: [fedora-arm] arm software floating point support going forward

2013-01-25 Thread Gordan Bobic
On Fri, 25 Jan 2013 10:22:23 -0600, Dennis Gilmore  
wrote:

Hi all,

I wanted to kick off a discussion, I think that with the work that
Seneca is doing for armv6hl to support the Raspberry Pi most of the
need for building sfp has gone away. I would like us to drop support
for sfp in F19 that means that anyone running a kirkwood based system
would get supported software updates for approximately 13 months from
now. with cubie boards and other devices coming around that are cheap
and more powerful and similar options I think there is little benefit
to continuing to support sfp.

Ive put in a request to get numbers of people using the arm and 
armhfp

portions of mirrormanager to get some idea of the number of users out
there, though i suspect most arm are raspberry pi and people building
in mock.


I am inclined to agree.

At the same time, however, this poses a few related questions?

With essentially dropping armv5tel, does it make sense to replace
it with what is very obviously going to be an arch with extremely
short-lived support-worthyness? Or would it be better to just drop
everything less than armv7hl and be done with it, and free up all
the resources for focusing on the primary target?

The focus question is particularly important considering that in
the near future there will also be the 64-bit ARM arch to support.

Or to put it another way - if armv5tel is drop-worthy, does
what is essentially one device (the Pi) warrant the maintenance
of an arch all by itself? If the answer to this is close to
yes, then what about dropping armv7hl in favour of armv6hl as
the only supported 32-bit ARM arch?

What is the performance gap, hardware being equal, between:

armv5tel -> armv6hl
armv6hl -> armv7hl

The answer to that question seems like it ought to factor
into any decision made.

Do any of the long standing issues of armv5tel (atomics?) go
away when using armv6hl?

Gordan
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