[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] [Qemu-ppc] [PATCH RFC v1 0/3] Enable MTTCG on PPC64

From: G 3
Subject: Re: [Qemu-devel] [Qemu-ppc] [PATCH RFC v1 0/3] Enable MTTCG on PPC64
Date: Thu, 6 Apr 2017 09:47:55 -0400

On Apr 6, 2017, at 9:32 AM, Cédric Le Goater wrote:

On 04/06/2017 03:28 PM, G 3 wrote:

On Apr 6, 2017, at 9:26 AM, Cédric Le Goater wrote:

Hello Nikunj,

On 04/06/2017 12:22 PM, Nikunj A Dadhania wrote:
The series enables Multi-Threaded TCG on PPC64

Patch 01: Use atomic_cmpxchg in store conditional
      02: Handle first write to page during atomic operation
03: Generate memory barriers for sync/isync and load/store conditional

Patches are based on ppc-for-2.10

Tested using following:
./ppc64-softmmu/qemu-system-ppc64 -cpu POWER8 -vga none - nographic -machine pseries,usb=off -m 2G -smp 8,cores=8,threads=1 -accel tcg,thread=multi f23.img

I tried it with a Ubuntu 16.04.2 guest using stress --cpu 8. It looked
good : the CPU usage of QEMU reached 760% on the host.

What was your guest operating system?

The guest is an Ubuntu 16.04.2 and the host is an Ubuntu 17.04.


Thank you for the information.

What you could do is run QEMU in emulation mode (non-kvm mode) and time how long it takes Ubuntu to boot up with one emulated core vs how long it takes to boot up on say 4 emulated cores. This would be a good start:

Boot up times:

one core:

two cores:

four cores:

eight cores:

reply via email to

[Prev in Thread] Current Thread [Next in Thread]