Messages in this thread | | | From | Andi Kleen <> | Subject | Re: is minimum udelay() not respected in preemptible SMP kernel-2.6.23? | Date | Thu, 8 Nov 2007 02:20:58 +0100 |
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> But I think we'd be best off stashing a single bit somewhere and > checking it at migrate time (relatively infrequent) rather than > copying and zeroing out a potentially enormous affinity mask every > time we disable migration (often, and in fast paths). Perhaps adding > TASK_PINNED to the task state flags would do it?
It would need to be a count to be able to nest it.
> > get_cpu() etc. could be changed to use this then too. > > Some users of get_cpu might be relying on it to avoid actual > preemption. In other words, we should have introduced a > migrate_disable() when we first discovered the preempt/per_cpu > conflict.
Ok perhaps it would make sense to migrate it step by step :- define a replacement for get_cpu and migrate over as users are getting audited and eventually deprecate old one.
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