On Thu, Apr 10, 2025 at 09:59:07AM -0400, Joel Fernandes wrote:
> Hello,
> Currently with my ARM machine of 288 CPUs, I am only seeing 56 of them used
> at a
> time. Any ideas if this is a bug or I am doing something wrong?
I regularly run with 80 CPUs, but perhaps the script's check for the
number of CPUs is broken on ARM? It currently relies on this:
getconf _NPROCESSORS_ONLN
(See identify_qemu_vcpus() in functions.sh.)
What should it be doing instead on ARM?
Huh. 56 does not go evenly into 288, either. Search me!
Thanx, Paul
> I started a batch of 36 SRCU-P runs, which is exactly 1 batch:
>
> $ sudo tools/testing/selftests/rcutorture/bin/kvm.sh --duration 120 --allcpus
> --configs "10*SRCU-P" --dryrun batches
> 1 SRCU-P 8
>
>
> 1 SRCU-P.2 8
>
> 1 SRCU-P.3 8
>
> 1 SRCU-P.4 8
>
> 1 SRCU-P.5 8
>
> 1 SRCU-P.6 8
>
> 1 SRCU-P.7 8
>
> 1 SRCU-P.8 8
>
> 1 SRCU-P.9 8
>
> 1 SRCU-P.10 8
>
> But, when I run it via:
> $ sudo tools/testing/selftests/rcutorture/bin/kvm.sh --duration 240 --cpus 288
> --configs "36*SRCU-P"
>
> ps shows me only 7 qemu instances of 8 CPUs each. However, weirdly it is only
> 1
> thread for each instance (thus its not even 56 CPUs, but rather 7 or so).
>
> 1496915 root 20 0 1684276 256996 66816 R 90.9 0.2 8:38.06
> qemu-system-aarch64 -enable-kvm -display none -no-reboot -smp 8 -net none
> -machine virt,gic-version=host -cpu host+
> 1496913 root 20 0 1684276 256996 66816 R 89.7 0.2 8:50.53
> qemu-system-aarch64 -enable-kvm -display none -no-reboot -smp 8 -net none
> -machine virt,gic-version=host -cpu host+
> 1496929 root 20 0 1684276 256996 66816 R 89.3 0.2 8:44.53
> qemu-system-aarch64 -enable-kvm -display none -no-reboot -smp 8 -net none
> -machine virt,gic-version=host -cpu host+
> 1496938 root 20 0 1684276 256996 66816 R 82.8 0.2 8:46.03
> qemu-system-aarch64 -enable-kvm -display none -no-reboot -smp 8 -net none
> -machine virt,gic-version=host -cpu host+
> 1496922 root 20 0 1684276 256996 66816 R 82.1 0.2 8:57.83
> qemu-system-aarch64 -enable-kvm -display none -no-reboot -smp 8 -net none
> -machine virt,gic-version=host -cpu host+
> 1496908 root 20 0 1684276 256996 66816 R 81.5 0.2 8:50.59
> qemu-system-aarch64 -enable-kvm -display none -no-reboot -smp 8 -net none
> -machine virt,gic-version=host -cpu host+
> 1496920 root 20 0 1684276 256996 66816 R 63.6 0.2 8:51.46
> qemu-system-aarch64 -enable-kvm -display none -no-reboot -smp 8 -net none
> -machine virt,gic-version=host -cpu host+
>
> Thanks.
>
>
