Messages in this thread |  | | Date | Mon, 11 Sep 2006 13:24:06 +0530 | From | Balbir Singh <> | Subject | Re: [ckrm-tech] [PATCH] BC: resource beancounters (v4) (added user memory) |
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Pavel Emelianov wrote: > Balbir Singh wrote: >> Dave Hansen wrote: >>> On Fri, 2006-09-08 at 11:33 +0400, Pavel Emelianov wrote: >>>> I'm afraid we have different understandings of what a "guarantee" is. >>> It appears so. >>> >>>> Don't we? >>>> Guarantee may be one of >>>> >>>> 1. container will be able to touch that number of pages >>>> 2. container will be able to sys_mmap() that number of pages >>>> 3. container will not be killed unless it touches that number of >>>> pages >>> A "death sentence" guarantee? I like it. :) >>> >>>> 4. anything else >>>> >>>> Let's decide what kind of a guarantee we want. >> I think of guarantees w.r.t resources as the lower limit on the resource. >> Guarantees and limits can be thought of as the range (guarantee, limit] >> for the usage of the resource. >> >>> I think of it as: "I will be allowed to use this many total pages, and >>> they are guaranteed not to fail." (1), I think. The sum of all of the >>> system's guarantees must be less than or equal to the amount of free >>> memory on the machine. >> Yes, totally agree. > > Such a guarantee is really a limit and this limit is even harder than > BC's one :) > > E.g. I have a node with 1Gb of ram and 10 containers with 100Mb > guarantee each. > I want to start one more. What shall I do not to break guarantees?
Don't start the new container or change the guarantees of the existing ones to accommodate this one :) The QoS design (done by the administrator) should take care of such use-cases. It would be perfectly ok to have a container that does not care about guarantees to set their guarantee to 0 and set their limit to the desired value. As Chandra has been stating we need two parameters (guarantee, limit), either can be optional, but not both.
> >>> If we knew to which NUMA node the memory was going to go, we might as >>> well take the pages out of the allocator. >>> >>> -- Dave >>>
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Balbir Singh, Linux Technology Center, IBM Software Labs - 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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