Messages in this thread | | | Date | Thu, 17 Feb 2005 09:57:33 -0500 (EST) | From | Steven Rostedt <> | Subject | Re: queue_work from interrupt Real time preemption2.6.11-rc2-RT-V0.7.37-03 |
| |
On Thu, 17 Feb 2005, Ingo Molnar wrote: > as long as it stays on a single CPU, could we allow softirq contexts to > preempt each other? I.e. we'd keep the per-CPU assumption (that is fair > and needed for performance anyway), but we'd allow NET_TX to preempt > NET_RX and vice versa. Would this corrupt the rx/tx queues? (i suspect > it would.) > > (anyway, by adding an explicit no-preempt section around the 'take > current rx queue private, then process it' on PREEMPT_RT it could be > made safe. I'm wondering whether there are any other deeper assumptions > about atomic separation of softirq contexts.) >
Ingo,
Wouldn't this cause a longer latency in these sections. I understand that turning preemption off doesn't stop interrupts that are not threaded, but especially on a UP, this would cause higher latencies for high priority processes when a lower priority process is heavy on network traffic.
As I mentioned earlier, what would it take to be able to group softirq threads that should not preempt each other, but still keep preemption available for other threads?
Actually, I guess I need to ask, what do you intend on doing to prioritize the softirq? Are you going to make a separate thread for each tasklet? Once I see what you're doing, I'll make something up to help handle this problem.
-- Steve
- 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/
| |