Re: [Qemu-devel] [PATCH v2 2/3] tests/vm: Do not abuse parallelism when KVM is not available

[Fam Zheng <famz@redhat.com>]

On Mon, 10/01 01:23, Philippe Mathieu-Daudé wrote:
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
> v2: Add get_default_jobs (Fam suggestion)
> ---
>  tests/vm/basevm.py | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/tests/vm/basevm.py b/tests/vm/basevm.py
> index 5a5fa09752..fc203e9f53 100755
> --- a/tests/vm/basevm.py
> +++ b/tests/vm/basevm.py
> @@ -202,6 +202,13 @@ class BaseVM(object):
>          return self._guest.qmp(*args, **kwargs)
>  
>  def parse_args(vm_name):
> +
> +    def get_default_jobs():
> +        if kvm_available():
> +            return multiprocessing.cpu_count() / 2
> +        else:
> +            return 1
> +
>      parser = optparse.OptionParser(
>          description="VM test utility.  Exit codes: "
>                      "0 = success, "
> @@ -214,7 +221,7 @@ def parse_args(vm_name):
>                        help="image file name")
>      parser.add_option("--force", "-f", action="store_true",
>                        help="force build image even if image exists")
> -    parser.add_option("--jobs", type=int, default=multiprocessing.cpu_count() / 2,
> +    parser.add_option("--jobs", type=int, default=get_default_jobs(),
>                        help="number of virtual CPUs")
>      parser.add_option("--verbose", "-V", action="store_true",
>                        help="Pass V=1 to builds within the guest")
> @@ -237,7 +244,7 @@ def main(vmcls):
>              return 1
>          logging.basicConfig(level=(logging.DEBUG if args.debug
>                                     else logging.WARN))
> -        vm = vmcls(debug=args.debug, vcpus=args.jobs)
> +        vm = vmcls(debug=args.debug, vcpus=args.jobs if kvm_available() else 0)

What's wrong with just using args.jobs? It defaults to 1 if kvm_available()
returns false, so I don't think we need another condition here.

>          if args.build_image:
>              if os.path.exists(args.image) and not args.force:
>                  sys.stderr.writelines(["Image file exists: %s\n" % args.image,
> @@ -248,7 +255,7 @@ def main(vmcls):
>              vm.add_source_dir(args.build_qemu)
>              cmd = [vm.BUILD_SCRIPT.format(
>                     configure_opts = " ".join(argv),
> -                   jobs=args.jobs,
> +                   jobs=args.jobs if kvm_available() else 1,

Again, can't we just use args.jobs?

>                     verbose = "V=1" if args.verbose else "")]
>          else:
>              cmd = argv
> -- 
> 2.19.0
> 

Fam