From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:51684) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gqZGz-0000Jr-7C for qemu-devel@nongnu.org; Mon, 04 Feb 2019 03:06:33 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gqZGw-0006Za-2j for qemu-devel@nongnu.org; Mon, 04 Feb 2019 03:06:32 -0500 Received: from mx1.redhat.com ([209.132.183.28]:47240) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gqZGq-0006Op-VO for qemu-devel@nongnu.org; Mon, 04 Feb 2019 03:06:27 -0500 From: Markus Armbruster References: <20190131130850.6850-1-yuval.shaia@oracle.com> <20190131130850.6850-8-yuval.shaia@oracle.com> <42ba3330-f7ca-b5c5-126f-8dd97e343d51@redhat.com> <20190131200816.GA2838@lap1> Date: Mon, 04 Feb 2019 09:00:31 +0100 In-Reply-To: <20190131200816.GA2838@lap1> (Yuval Shaia's message of "Thu, 31 Jan 2019 22:08:17 +0200") Message-ID: <87ef8ot23k.fsf@dusky.pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Qemu-devel] [PATCH 07/10] monitor: Expose pvrdma device statistics counters List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Yuval Shaia Cc: Eric Blake , qemu-devel@nongnu.org, dgilbert@redhat.com, Stefan Hajnoczi Yuval Shaia writes: > 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 >> > --- >> > 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. I figure that depends on the trace backend. The "log" backend can be problematic for high tracing rates. "ftrace", "dtrace" and "ust" backends should support such cases. Stefan, any advice? > 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.