Re: [patch] sched-HT-2.6.0-test11-A5

[Ingo Molnar]

On Mon, 8 Dec 2003, William Lee Irwin III wrote:

> This appears to either leak migration threads or not set
> rq->cpu[x].migration_thread basically ever for x > 0. Or if they are
> shut down, how? Also, what makes sure cpu_idx is initialized before they
> wake? They'll all spin on cpu_rq(0)->lock, no?

yep, it just leaks migration threads. Not a big problem right now, but for
hotplug CPU support this needs to be fixed.

> Furthermore, sched_map_runqueue() is performed after all the idle
> threads are running and all the notifiers have kicked the migration
> threads, but does no locking whatsoever.

yep - at this point nothing else is really supposed to run but you are
right it must be locked properly.

> Also, does init_idle() need to move into rest_init()? It should be
> equivalent to its current placement.

this is a leftover of a change that went into 2.6 already. I've removed
this change.

> Why not per_cpu for __rq_idx[] and __cpu_idx[]? This would have the
> advantage of residing on node-local memory for sane architectures (and
> perhaps in the future, some insane ones).

agreed, i've changed them to be per-cpu.

new patch with all your suggestions included is at:

  redhat.com/~mingo/O(1)-scheduler/sched-SMT-2.6.0-test11-C1

it also includes the bounce-to-cpu1 fix from/for Anton.

	Ingo
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