On Thu, 8 Feb 2018 09:29:28 +0000 Daniel P. Berrangé <berra...@redhat.com> wrote:
> On Wed, Feb 07, 2018 at 12:50:14PM -0500, Luiz Capitulino wrote: > > Signed-off-by: Luiz Capitulino <lcapitul...@redhat.com> > > --- > > qapi-schema.json | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/qapi-schema.json b/qapi-schema.json > > index 82d6f12b53..0665a14dba 100644 > > --- a/qapi-schema.json > > +++ b/qapi-schema.json > > @@ -526,6 +526,10 @@ > > # > > # Returns a list of information about each virtual CPU. > > # > > +# WARNING: This command incurs a performance penalty for latency > > +# sensitive workloads and hence it's not recommended to > > +# to be used in production. Use query-cpus-fast instead > > I suggest being more explicit about exactly what the problem is, so people > understand implications if they choose to still use it. ie I'll add your text. > > This command causes vCPU threads to exit to userspace, which causes > an small interruption guest CPU execution. This will have a negative > impact on realtime guests and other latency sensitive guest workloads. > It is recommended to use query-cpus-fast instead of this command to > avoid the vCPU interruption. > > Regards, > Daniel
