Messages in this thread | | | Date | Mon, 13 Jun 2016 15:53:02 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 2/2] s390/topology: add drawer scheduling domain level |
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On Mon, Jun 13, 2016 at 03:19:42PM +0200, Martin Schwidefsky wrote: > On Mon, 13 Jun 2016 15:06:47 +0200 > Peter Zijlstra <peterz@infradead.org> wrote: > > > On Mon, Jun 13, 2016 at 01:22:30PM +0200, Heiko Carstens wrote: > > > Yes, and actually we are all virt/LPAR always, so this is unfortunately not > > > very easy to do. And yes, I do agree that for the 1:1 case it most likely > > > would make sense, however we don't have any run-time guarantee to stay 1:1. > > > > One option would be to make it a boot option; such that the > > administrator has to set it. At that point, if the admin creates > > multiple LPARs its on him. > > Unfortunately not good enough. The LPAR code tries to optimize the layout > at the time a partition is activated. The landscape of already running > partitions can change at this point.
Would not the admin _know_ this? It would be him activating partitions after all, no?
> To get around this you would have to activate *all* partitions first and > then start the operating systems in a second step.
Arguably, you only care about the single partition covering the entire machine case, so I don't see that being a problem.
Again, admin _knows_ this.
> And then there is concurrent repair which will move things around if a > piece of memory goes bad. This happens rarely though.
That would be magic disturbance indeed, nothing much to do about that.
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