On 02/16/2018 10:08 AM, Viktor Mihajlovski 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 Drop "halted" field as it can not be retrieved in a fast
    way on most architectures

  o Drop irrelevant fields such as "current", "pc" and "arch"

  o Rename some fields for better clarification & proper naming

Signed-off-by: Luiz Capitulino <lcapitul...@redhat.com>
Signed-off-by: Viktor Mihajlovski <mihaj...@linux.vnet.ibm.com>
  cpus.c           | 38 ++++++++++++++++++++++++++++++
  qapi-schema.json | 70 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  2 files changed, 108 insertions(+)

Reviewed-by: Eric Blake <ebl...@redhat.com>

Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org

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