On Mon, 12 Feb 2018 13:14:31 +0100 Viktor Mihajlovski <mihaj...@linux.vnet.ibm.com> wrote:
> From: Luiz Capitulino <lcapitul...@redhat.com> > > The query-cpus command has an extremely serious side effect: > it always interrupts all running vCPUs so that they can run > ioctl calls. This can cause a huge performance degradation for > some workloads. And most of the information retrieved by the > ioctl calls are not even used by query-cpus. > > This commit introduces a replacement for query-cpus called > query-cpus-fast, which has the following features: > > o Never interrupt vCPUs threads. query-cpus-fast only returns > vCPU information maintained by QEMU itself, which should be > sufficient for most management software needs > > o Make "halted" field optional: we only return it if the > halted state is maintained by QEMU. But this also gives > the option of dropping the field in the future (see below) > > o Drop irrelevant fields such as "current", "pc" and "arch" > > o Drop field "halted" since it can't be provided fast reliably > and is too volatile on most architectures to be really useful > > o Rename some fields for better clarification & proper naming > standard > > Signed-off-by: Luiz Capitulino <lcapitul...@redhat.com> > Signed-off-by: Viktor Mihajlovski <mihaj...@linux.vnet.ibm.com> > --- > cpus.c | 38 ++++++++++++++++++++++++++++ > hmp-commands-info.hx | 14 +++++++++++ > hmp.c | 21 ++++++++++++++++ > hmp.h | 1 + > qapi-schema.json | 70 > ++++++++++++++++++++++++++++++++++++++++++++++++++++ > 5 files changed, 144 insertions(+) Reviewed-by: Cornelia Huck <coh...@redhat.com>
