On Wed, 2011-03-09 at 14:15 +0100, Martin Schwidefsky wrote: > On Wed, 09 Mar 2011 12:33:49 +0100 > Peter Zijlstra <pet...@infradead.org> wrote: > > > On Wed, 2011-03-09 at 11:19 +0100, Peter Zijlstra wrote: > > > > It appears that this corresponds to one CPU deciding to rebuild the > > > > sched domains. There's various reasons why that can happen, the typical > > > > one in our case is the new VPNH feature where the hypervisor informs us > > > > of a change in node affinity of our virtual processors. s390 has a > > > > similar feature and should be affected as well. > > > > > > Ahh, so that's triggering it :-), just curious, how often does the HV do > > > that to you? > > > > OK, so Ben told me on IRC this can happen quite frequently, to which I > > must ask WTF were you guys smoking? Flipping the CPU topology every time > > the HV scheduler does something funny is quite insane. And you did that > > without ever talking to the scheduler folks, not cool. > > > > That is of course aside from the fact that we have a real bug there that > > needs fixing, but really guys, WTF! > > Just for info, on s390 the topology change events are rather infrequent. > They do happen e.g. after an LPAR has been activated and the LPAR > hypervisor needs to reshuffle the CPUs of the different nodes.
But if you don't also update the cpu->node memory mappings (which I think it near impossible) what good is it to change the scheduler topology? _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
