Hi Somnath,

gem5 is a single-threaded simulator, for the most part. There is some
support for assigning event queues to multiple threads, but it isn't fully
fleshed out except in very limited circumstances (e.g., two systems
connected via ethernet).

However, there are a number of different ways to speed up simulation,
especially for fast-forwarding to the region of interest (ROI). A few are
listed below.
1. Use checkpoints. You can run until the beginning of the ROI then take a
checkpoint. In the future, you can just load that checkpoint.
2. Fast-forward with a simpler CPU model (e.g., atomic or simple timing)
then switch to a detailed CPU model when you reach the region of interest.
3. Use the KVM CPU. If your native host machine uses the same ISA as the
simulated system you can use the virtualization support in KVM to
fast-forward gem5's execution at native speeds. For instance, I can boot
linux with 32 simulate cores in about 20 seconds with the KVM CPU.

IIRC, you can use up to 64 CPUs with gem5, the number may be different. You
need to make sure to use a Linux kernel that is compiled to use that many
CPUs, though.

Cheers,
Jason

On Tue, Feb 21, 2017 at 4:58 AM Mukherjee, Somnath <somn...@ti.com> wrote:

> Hi,
>
> I need some help from the community. Is there a way we can run / spawn the
> gem5 simulator on multiple host CPUs?
>
> I am booting Ubuntu on gem5 and looks like it’s running very slow when I
> run a few programs once the Linux is boot-ed.
>
> Is there a way I can make the gem5 run / boot  Ubuntu on multiple host
> CPUs?
>
> Or is the execution of gem5 mostly serial?
>
>
>
> Regards,
>
> Somnath Mukherjee
>
> Bangalore
>
>
> _______________________________________________
> gem5-users mailing list
> gem5-users@gem5.org
> http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
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