From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53785) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X8CBL-0007XH-Rc for qemu-devel@nongnu.org; Fri, 18 Jul 2014 13:43:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1X8CBD-0001qB-MH for qemu-devel@nongnu.org; Fri, 18 Jul 2014 13:42:55 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60352) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X8CBD-0001q7-Da for qemu-devel@nongnu.org; Fri, 18 Jul 2014 13:42:47 -0400 Date: Fri, 18 Jul 2014 18:42:41 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20140718174241.GG10517@work-vm> References: <1405596081-29701-1-git-send-email-sanidhya.iiith@gmail.com> <20140718105655.GB2384@work-vm> <53C95945.8010402@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <53C95945.8010402@gmail.com> Subject: Re: [Qemu-devel] [PATCH v4 0/8] Obtain dirty bitmap via VM logging List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Sanidhya Kashyap Cc: Amit Shah , qemu list , Juan Quintela * Sanidhya Kashyap (sanidhya.iiith@gmail.com) wrote: > > > > 1) Do you have some examples of output? > > Can you see hot areas in the kernel or something else? > > > > I looked at it sometimes back. I will try to provide some images (as > suggested by you earlier) to see any consistently used areas. > > > 2) 'frequency' is probably the wrong name for the parameter you have; since > > the parameter is actually the delay between epochs, where as frequency > > would imply the number of epochs/second. > > > > will surely change it to period. It is pointed out by Eric too. > > > 3) The change to runstates is interesting; up until now 'runstate' is really > > mostly about the state of the CPU, but by adding migration/dumping to the > > states you're trying to convey more in that single state variable; I'm not > > quite sure if this is the right thing to do or not. > > > > Is there any alternative that can allow us to execute only one of the > processes - either migration or bitmap dump. One very basic approach > that I have thought is about using a global variable but don't know > whether that is a good option or not. > > Any other alternative is welcomed. I think a global variable is the right thing; something like 'dirty_bitmap_user' being an enum between none, migration, dumping would make sense to me. While adding global variables ia a bad thing, since the dirty bitmap already is global all you're doing really is adding an extra bit of state to it. If you have something like char *dirty_bitmap_user_as_string() then your test in your qml code would look something like: if (dirty_bitmap_user != dbu_none) { error_report("Can't do dirty dumping since %s is in use", dirty_bitmap_user_as_string()); } and then if more things use it in the future the existing users don't have to change. Dave > > ----- > > Sanidhya Kashyap -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK