On Thu, 16 Jul 2020 07:37:17 +0200 Markus Armbruster <arm...@redhat.com> wrote:
> David Gibson <dgib...@redhat.com> writes: > > [...] > [...] > [...] > [...] > [...] > [...] > [...] > [...] > [...] > > > > ... as you say, 256 shouldn't really be a problem. I was concerned > > about LMB DRCs rather than PCI DRCs. To have that show up, you might > > need to create a machine with a large difference between initial memory > > and maxmem - I think you'll get a DRC object for every 256MiB in there, > > which can easily get into the thousands for large (potential) memory > > VMs. > > Okay, I can reproduce: with -m 256,128G, /machine has 549 children, of > which 511 are spapr-drc-lmb. Ok. > > I don't know what the config was that showed up this problem in the > > first place, and whether that could be the case there. > > Thomas reported device-introspect-test -m slow has become much slower > for ppc64. Bisection traced it to my commit e8c9e65816 "qom: Make "info > qom-tree" show children sorted". Uses default memory size, no > spapr-drc-lmb as far as I remember. Ok, I think that nixes my theory. > >> > Though avoiding a n^2 behaviour here is probably a good > >> > idea anyway. > >> > >> Agreed. > > Patch posted: > > Subject: [PATCH for-5.1 5/5] qom: Make info qom-tree sort children more > efficiently > Message-Id: <20200714160202.3121879-6-arm...@redhat.com> > -- David Gibson <dgib...@redhat.com> Principal Software Engineer, Virtualization, Red Hat
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