On Thu, Sep 10, 2015 at 01:42:57AM -0700, Peter Crosthwaite wrote: > On Wed, Sep 9, 2015 at 11:28 PM, David Gibson > <da...@gibson.dropbear.id.au> wrote: > > The dynamic reconfiguration (hotplug) code for the pseries machine type > > uses a "DR connector" QOM object for each resource it will be possible > > to hotplug. Each of these is added to its owner using > > object_property_add_child(owner, "dr-connector[*], ...); > > > > > This works ok for most cases, but gets ugly when allowing large amounts of > > hotplugged RAM. For RAM, there's a DR connector object for every 256MB of > > potential memory. So if maxmem=2T, for example, there are >250,000 objects > > under the same parent. > > > > The QOM interfaces aren't really designed for this. In particular > > object_property_add() has O(n^2) time complexity (in the number of existing > > children) for the [*] case. First it has a linear search through array > > indices to find a free slot, each of which is attempted to a recursive call > > to object_property_add() with a specific [N]. Those calls are O(n) because > > there's a linear search through all properties to check for duplicates. > > > > Does this help? I think it's already queued: > > >http://lists.nongnu.org/archive/html/qemu-devel/2015-07/msg05790.html
It doesn't help our case; it's basically a fix for a different
instance of the same problem.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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