Messages in this thread | | | Date | Wed, 10 Nov 2004 11:14:52 -0800 | From | Andrew Morton <> | Subject | Re: kthread realtime priorities and exporting sys_sched_setscheduler() |
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dcn@sgi.com (Dean Nelson) wrote: > > I'm trying to push XP[C|NET] out to the community. (For further details: > http://marc.theaimsgroup.com/?l=linux-ia64&m=109337050919186&w=2 ) > > An objection was raised over the exporting and calling of > sys_sched_setscheduler(), which XPC calls to make its kthreads > run at realtime priorities. Without this change we found that it > was possible for user processes to be given a higher effective > priority than the kthreads used by XPC. The upshot of this was > that the latencies incurred by XPC increased 300 times in the > test example given. If XPC's kthreads were given realtime > priorities this did not happen. (For further details: > http://marc.theaimsgroup.com/?l=linux-ia64&m=109337503100067&w=2 )
I'd disagree with Christoph on that. Being able to set the scheduling policy from a module-based kernel thread is a sensible thing to be able to do, and you can do it by issuing a direct trap anyway.
EXPORT_SYMBOL_GPL() would be preferred.
Possibly it could be done by adding a variant of kthread_create() which has a new `policy' argument, but it doesn't really seem worth the fuss. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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