[musl] Linux distribution for using RISC-V musl?

[musl] Linux distribution for using RISC-V musl?

[ardi]

Hi!

From what I'm reading, it seems like the RISC-V (64 bit) version of
musl is considered to be in working status as of now. I'd like to give
it a try with a RISC-V emulator, but first I'd wish to know which
Linux distribution(s) use the people who have been developing/testing
musl in RISC-V. Have they succeeded in completely replacing GNU libc
by musl in such distribution(s) ?

Also, I've read that QEMU is able to emulate multicore RISC-V CPUs.
Does musl support multicore RISC-V in 64bit? I mean, if I configure a
multicore RISC-V in QEMU and I try to build a parallel loop using
OpenMP for example, will such loop be parallelized if I'm using musl?

Thanks a lot,

ardi

Re: [musl] Linux distribution for using RISC-V musl?

[Szabolcs Nagy]

* ardi <ardillasdelmonte@gmail.com> [2021-04-10 14:08:31 +0200]:
> Also, I've read that QEMU is able to emulate multicore RISC-V CPUs.
> Does musl support multicore RISC-V in 64bit? I mean, if I configure a
> multicore RISC-V in QEMU and I try to build a parallel loop using
> OpenMP for example, will such loop be parallelized if I'm using musl?

yes.

this has not much to do with the libc though.
openmp uses pthreads, pthreads uses clone and
clone is implemented by the os in some way.
whether things are parallel is not in the hands
of the libc and the logic is not target dependent,
the libc works the same way on x86_64 as on riscv.
there can be target specific synchronization bugs
in the libc, but those are just bugs.

Re: [musl] Linux distribution for using RISC-V musl?

[ardi]

Really useful!! Thanks a lot!

On Sat, Apr 10, 2021 at 2:24 PM Szabolcs Nagy <nsz@port70.net> wrote:
>
> * ardi <ardillasdelmonte@gmail.com> [2021-04-10 14:08:31 +0200]:
> > Also, I've read that QEMU is able to emulate multicore RISC-V CPUs.
> > Does musl support multicore RISC-V in 64bit? I mean, if I configure a
> > multicore RISC-V in QEMU and I try to build a parallel loop using
> > OpenMP for example, will such loop be parallelized if I'm using musl?
>
> yes.
>
> this has not much to do with the libc though.
> openmp uses pthreads, pthreads uses clone and
> clone is implemented by the os in some way.
> whether things are parallel is not in the hands
> of the libc and the logic is not target dependent,
> the libc works the same way on x86_64 as on riscv.
> there can be target specific synchronization bugs
> in the libc, but those are just bugs.
>

Re: [musl] Linux distribution for using RISC-V musl?

[Nagakamira]

[-- Attachment #1: Type: text/plain, Size: 1057 bytes --]

Try ataraxia gnu/linux! But llvm lto have to be fixed.

вс, 11 апр. 2021 г., 00:17 ardi <ardillasdelmonte@gmail.com>:

> Really useful!! Thanks a lot!
>
> On Sat, Apr 10, 2021 at 2:24 PM Szabolcs Nagy <nsz@port70.net> wrote:
> >
> > * ardi <ardillasdelmonte@gmail.com> [2021-04-10 14:08:31 +0200]:
> > > Also, I've read that QEMU is able to emulate multicore RISC-V CPUs.
> > > Does musl support multicore RISC-V in 64bit? I mean, if I configure a
> > > multicore RISC-V in QEMU and I try to build a parallel loop using
> > > OpenMP for example, will such loop be parallelized if I'm using musl?
> >
> > yes.
> >
> > this has not much to do with the libc though.
> > openmp uses pthreads, pthreads uses clone and
> > clone is implemented by the os in some way.
> > whether things are parallel is not in the hands
> > of the libc and the logic is not target dependent,
> > the libc works the same way on x86_64 as on riscv.
> > there can be target specific synchronization bugs
> > in the libc, but those are just bugs.
> >
>

[-- Attachment #2: Type: text/html, Size: 1597 bytes --]

Re: [musl] Linux distribution for using RISC-V musl?

[ardi]

[-- Attachment #1: Type: text/plain, Size: 1532 bytes --]

Ataraxia looks really interesting: LLVM+musl+Toybox is the kind of
distribution I’d love to have. Is there any page explaining how to install
Ataraxia on RISCV? The docs only cover x86 and PPC, and besides the latest
RISCV release I found is from 2019 or so...

Also, regarding LLVM LTO, what’s the ticket for following that bug? I
searched for it and all what I found is.

Thanks!!


Nagakamira <nagakamira@gmail.com> wrote:

> Try ataraxia gnu/linux! But llvm lto have to be fixed.
>
> вс, 11 апр. 2021 г., 00:17 ardi <ardillasdelmonte@gmail.com>:
>
>> Really useful!! Thanks a lot!
>>
>> On Sat, Apr 10, 2021 at 2:24 PM Szabolcs Nagy <nsz@port70.net> wrote:
>> >
>> > * ardi <ardillasdelmonte@gmail.com> [2021-04-10 14:08:31 +0200]:
>> > > Also, I've read that QEMU is able to emulate multicore RISC-V CPUs.
>> > > Does musl support multicore RISC-V in 64bit? I mean, if I configure a
>> > > multicore RISC-V in QEMU and I try to build a parallel loop using
>> > > OpenMP for example, will such loop be parallelized if I'm using musl?
>> >
>> > yes.
>> >
>> > this has not much to do with the libc though.
>> > openmp uses pthreads, pthreads uses clone and
>> > clone is implemented by the os in some way.
>> > whether things are parallel is not in the hands
>> > of the libc and the logic is not target dependent,
>> > the libc works the same way on x86_64 as on riscv.
>> > there can be target specific synchronization bugs
>> > in the libc, but those are just bugs.
>> >
>>
>

[-- Attachment #2: Type: text/html, Size: 2467 bytes --]

Re: [musl] Linux distribution for using RISC-V musl?

[Nagakamira]

[-- Attachment #1: Type: text/plain, Size: 1749 bytes --]

lto on riscv64 is broken I will revert the commit when I will have free
time and make it work

пн, 12 апр. 2021 г., 13:30 ardi <ardillasdelmonte@gmail.com>:

> Ataraxia looks really interesting: LLVM+musl+Toybox is the kind of
> distribution I’d love to have. Is there any page explaining how to install
> Ataraxia on RISCV? The docs only cover x86 and PPC, and besides the latest
> RISCV release I found is from 2019 or so...
>
> Also, regarding LLVM LTO, what’s the ticket for following that bug? I
> searched for it and all what I found is.
>
> Thanks!!
>
>
> Nagakamira <nagakamira@gmail.com> wrote:
>
>> Try ataraxia gnu/linux! But llvm lto have to be fixed.
>>
>> вс, 11 апр. 2021 г., 00:17 ardi <ardillasdelmonte@gmail.com>:
>>
>>> Really useful!! Thanks a lot!
>>>
>>> On Sat, Apr 10, 2021 at 2:24 PM Szabolcs Nagy <nsz@port70.net> wrote:
>>> >
>>> > * ardi <ardillasdelmonte@gmail.com> [2021-04-10 14:08:31 +0200]:
>>> > > Also, I've read that QEMU is able to emulate multicore RISC-V CPUs.
>>> > > Does musl support multicore RISC-V in 64bit? I mean, if I configure a
>>> > > multicore RISC-V in QEMU and I try to build a parallel loop using
>>> > > OpenMP for example, will such loop be parallelized if I'm using musl?
>>> >
>>> > yes.
>>> >
>>> > this has not much to do with the libc though.
>>> > openmp uses pthreads, pthreads uses clone and
>>> > clone is implemented by the os in some way.
>>> > whether things are parallel is not in the hands
>>> > of the libc and the logic is not target dependent,
>>> > the libc works the same way on x86_64 as on riscv.
>>> > there can be target specific synchronization bugs
>>> > in the libc, but those are just bugs.
>>> >
>>>
>>

[-- Attachment #2: Type: text/html, Size: 2971 bytes --]

Re: [musl] Linux distribution for using RISC-V musl?

[Khem Raj]

Hi Ardi

RV64/musl combo is well supported in OpenEmbedded/Yocto perhaps
buildroot also supports this combo well
you can try Yoe Distro which is based on Yocto

https://github.com/YoeDistro/yoe-distro

On Sat, Apr 10, 2021 at 5:09 AM ardi <ardillasdelmonte@gmail.com> wrote:
>
> Hi!
>
> From what I'm reading, it seems like the RISC-V (64 bit) version of
> musl is considered to be in working status as of now. I'd like to give
> it a try with a RISC-V emulator, but first I'd wish to know which
> Linux distribution(s) use the people who have been developing/testing
> musl in RISC-V. Have they succeeded in completely replacing GNU libc
> by musl in such distribution(s) ?
>
> Also, I've read that QEMU is able to emulate multicore RISC-V CPUs.
> Does musl support multicore RISC-V in 64bit? I mean, if I configure a
> multicore RISC-V in QEMU and I try to build a parallel loop using
> OpenMP for example, will such loop be parallelized if I'm using musl?
>
> Thanks a lot,
>
> ardi

Re: [musl] Linux distribution for using RISC-V musl?

[ardi]

Thanks a lot, Khem,

However, I feel like Yocto is beyond reach of my current skills.
Someday I'll dig into low-level details of distributions, and I feel
really tempted to build a Linux from scratch (a la "Aboriginal Linux"
http://landley.net/aboriginal/ ), but for the moment my skill is more
into user-land development (with some internal compiler skills) than
into distribution engineering. So I feel more prone to just use
available images that I can just feed into QEMU (or other emulators).

Kind regards and thanks a lot,

Ardi



On Sat, Apr 10, 2021 at 4:17 PM Khem Raj <raj.khem@gmail.com> wrote:
>
> Hi Ardi
>
> RV64/musl combo is well supported in OpenEmbedded/Yocto perhaps
> buildroot also supports this combo well
> you can try Yoe Distro which is based on Yocto
>
> https://github.com/YoeDistro/yoe-distro
>
> On Sat, Apr 10, 2021 at 5:09 AM ardi <ardillasdelmonte@gmail.com> wrote:
> >
> > Hi!
> >
> > From what I'm reading, it seems like the RISC-V (64 bit) version of
> > musl is considered to be in working status as of now. I'd like to give
> > it a try with a RISC-V emulator, but first I'd wish to know which
> > Linux distribution(s) use the people who have been developing/testing
> > musl in RISC-V. Have they succeeded in completely replacing GNU libc
> > by musl in such distribution(s) ?
> >
> > Also, I've read that QEMU is able to emulate multicore RISC-V CPUs.
> > Does musl support multicore RISC-V in 64bit? I mean, if I configure a
> > multicore RISC-V in QEMU and I try to build a parallel loop using
> > OpenMP for example, will such loop be parallelized if I'm using musl?
> >
> > Thanks a lot,
> >
> > ardi