SPARC32 : SMP

[Olivier Danet]

I splitted the patch.

It was tested with an old Linux distro (RH 4.2) and with NetBSD.
The SMP kernel must be selected during install.

Here is, for example, a NetBSD/sparc32 image with SMP enabled :

temlib.org/pub/net702.qcow.bz2

qemu-system-sparc net702.qcow  -M SS-20 -vga cg3 -smp 2

This SMP mode used to work a while ago, but it has so far no practical purpose as enabling it slows down QEMU considerably.

[Mark Cave-Ayland]

On 09/01/17 20:40, Olivier Danet wrote:
> I splitted the patch.
>
> It was tested with an old Linux distro (RH 4.2) and with NetBSD.
> The SMP kernel must be selected during install.
>
> Here is, for example, a NetBSD/sparc32 image with SMP enabled :
>
> temlib.org/pub/net702.qcow.bz2
>
> qemu-system-sparc net702.qcow  -M SS-20 -vga cg3 -smp 2
>
> This SMP mode used to work a while ago, but it has so far no practical purpose as enabling it slows down QEMU considerably.

Thanks Olivier - these look good, so I've pushed them to master.

At the moment TCG only runs on a single CPU, so adding multiple CPUs
simply halves the work that each can do.

However the patchset for MTTCG (Multi-Threading TCG) is nearing
completion which will allow each virtual CPU to run in a separate
thread, and hence on a separate CPU. It would take a bit of work to
enable it for SPARC, but it's certainly not impossible:
https://lists.gnu.org/archive/html/qemu-devel/2017-01/msg05903.html.

ATB,

Mark.