Messages in this thread | ![/](/images/icornerl.gif) | | Date | Mon, 19 Sep 2005 14:32:04 -0700 (PDT) | From | Christoph Lameter <> | Subject | Re: NUMA mempolicy /proc code in mainline shouldn't have been merged |
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On Mon, 19 Sep 2005, Andi Kleen wrote:
> On Mon, Sep 19, 2005 at 10:11:20AM -0700, Christoph Lameter wrote: > > However, one still does not know which memory section (vma) is allocated > > on which nodes. And this may be important since critical data may need to > > Maybe. Well sure of things could be maybe important. Or maybe not. > Doesn't seem like a particularly strong case to add a lot of ugly > code though.
We gradually need to fix the deficiencies of the policy layer. Calling fixes "ugly code" and refusing to discuss solutions does not help anyone.
> > External memory policy management is a necessary feature for system > > administration, batch process scheduling as well as for testing and > > debugging a system. > > I'm not convinced of this at all. Most of these things proposed so far > can be done much simpler with 90% of the functionality (e.g. just swapoff > per process for migration) , and I haven't seen a clear rationale except > for lots of maybes that the missing 10% are worth all the complexity > you seem to plan to add.
Have you ever had the challenge to work with large HPC applications on a large NUMA system? Which things? Many HPC apps do not use swap space at all and we likely wont be using swap for page migration (see Marcelo's work on a migration cache). All I have heard is you imagining complex solutions ("performance counters" etc) to things that would be simple if the policy layer would be up to the task. - 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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