Re: [Qemu-devel] [PATCH 07/10] monitor: Expose pvrdma device statistics counters

[Yuval Shaia]

On Thu, Jan 31, 2019 at 07:17:16AM -0600, Eric Blake wrote:
> On 1/31/19 7:08 AM, Yuval Shaia wrote:
> > Signed-off-by: Yuval Shaia <address@hidden>
> > ---
> >  hmp-commands-info.hx | 14 ++++++++++++++
> >  monitor.c            |  6 ++++++
> >  2 files changed, 20 insertions(+)

Hi Eric,

> 
> Commit message should state WHY this is being added as an HMP-only
> command, and does not have a QMP counterpart.  It may be okay if the
> interface is only designed to be useful to developers, but having that
> justification in the git log is important.

Thanks for your review.

See, i need this interface mainly for development/debug purposes, to help
troubleshot problems and to give insights to what device "is doing".

Trace points are great but not effective in high load.
QMP as i see it, and correct me if i'm wrong, is used to report management
events etc and also here, is not effective in high load.

I choose this interface as it is interactive, i.e. whenever i need the info
i trigger 'info pvrdmastats' command from the monitor console.

During my research i notice that some devices (or families) have nice user
interface via virsh (blkstat, ifstat, memstat etc). Is it the preferred way
for non-devel/debug purposes?

If this is the correct method for this purpose then let me know and i'll
update the git log message accordingly.

Thanks.

> 
> -- 
> Eric Blake, Principal Software Engineer
> Red Hat, Inc.           +1-919-301-3226
> Virtualization:  qemu.org | libvirt.org
>