Messages in this thread | | | Date | Tue, 7 Nov 2006 21:31:47 +0100 | From | Ingo Molnar <> | Subject | Re: + sched-use-tasklet-to-call-balancing.patch added to -mm tree |
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* Christoph Lameter <clameter@sgi.com> wrote:
> Tasklets are scheduled on the same cpu that triggered the tasklet. > They are just moved to other processors if the processor goes down. So > that aspect is fine. We just need a tasklet struct per cpu. > > User a per cpu tasklet to schedule rebalancing > > Turns out that tasklets have a flag that only allows one instance to > run on all processors. So we need a tasklet structure for each > processor.
Per-CPU tasklets are equivalent to softirqs, with extra complexity and overhead ontop of it :-)
so please just introduce a rebalance softirq and attach the scheduling rebalance tick to it. But i'd suggest to re-test on the 4096-CPU box, maybe what 'fixed' your workload was the global serialization of the tasklet. With a per-CPU softirq approach we are i think back to the same situation that broke your system before.
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