Messages in this thread | ![/](/images/icornerl.gif) | | Date | Sat, 19 Apr 2003 13:38:37 -0700 | From | Andrew Morton <> | Subject | Re: 2.5.67-mm4 & IRQ balancing |
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Philippe Gramoullé <philippe.gramoulle@mmania.com> wrote: > > [ SMP IRQ distribution ] > > Is this what you are looking for ? and are the values changes meaningful ?
Looks good to me. But it didn't affect your machine at all, did it?
This stuff only counts when the machine is doing a lot of work. The current IRQ balancer works well under high interrupt frequencies, but does quite the wrong thing if you're doing a lot of softirq work at low interrupt frequencies (gige routing with NAPI).
My gut feel is that we'll never get this right with a single in-kernel IRQ balancer. So the proposal is to pull the IRQ balancer out altogether and to then merge Arjan's userspace balancer into the main kernel tree.
It's a little radical to go placing userspace daemons into the kernel tree, but I think it is appropriate - this thing is very tightly coupled to the kernel.
The proposal has these advantages:
- No version skew problems: if the format of /proc/interrupts changes, we patch the irq balance daemon at the same time.
- Can build irqbalanced into the intial initramfs image as part of kernel build. (lacking klibc, we would need to statically link against glibc)
- Doing it in userspace means that we can do more things.
- The balancer can "know about" the differences between NICs, disk controllers, etc.
- The balancer can be controlled by config files: "I am a router"
- The balancer can support non-x86 architectures
Anyway, that's the theory. None of it has been done yet. - 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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