Messages in this thread | | | Date | Fri, 02 Mar 2007 09:48:38 +0530 | From | Balbir Singh <> | Subject | Re: The performance and behaviour of the anti-fragmentation related patches |
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Linus Torvalds wrote: > > On Fri, 2 Mar 2007, Balbir Singh wrote: >>> My personal opinion is that while I'm not a huge fan of virtualization, >>> these kinds of things really _can_ be handled more cleanly at that layer, >>> and not in the kernel at all. Afaik, it's what IBM already does, and has >>> been doing for a while. There's no shame in looking at what already works, >>> especially if it's simpler. >> Could you please clarify as to what "that layer" means - is it the >> firmware/hardware for virtualization? or does it refer to user space? > > Virtualization in general. We don't know what it is - in IBM machines it's > a hypervisor. With Xen and VMware, it's usually a hypervisor too. With > KVM, it's obviously a host Linux kernel/user-process combination. >
Thanks for clarifying.
> The point being that in the guests, hotunplug is almost useless (for > bigger ranges), and we're much better off just telling the virtualization > hosts on a per-page level whether we care about a page or not, than to > worry about fragmentation. > > And in hosts, we usually don't care EITHER, since it's usually done in a > hypervisor. > >> It would also be useful to have a resource controller like per-container >> RSS control (container refers to a task grouping) within the kernel or >> non-virtualized environments as well. > > .. but this has again no impact on anti-fragmentation. >
Yes, I agree that anti-fragmentation and resource management are independent of each other. I must admit to being a bit selfish here, in that my main interest is in resource management and we would love to see a well written and easy to understand resource management infrastructure and controllers to control CPU and memory usage. Since the issue of per-container RSS control came up, I wanted to ensure that we do not mix up resource control and anti-fragmentation.
-- Warm Regards, Balbir Singh Linux Technology Center IBM, ISTL - 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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