>Have we all agreed by now that the performance hit is relatively minor >(unmeasurable for most cases due to it being less than the noise of the >samples) from 4-level page tables? Do I need to do any more performance >measurements? The transaction processing benchmark hit, although small isn't minor. Ken has had to fight for every 0.1% increment ... so setting him back by 0.2% with a patch that is only needed for some very large systems (>3192cpus according to your October 28th post) is a tough thing to do. Once you've worked out the remaining kinks in the patch so that 64K page (and 4GB hugetlb page) work, I can take it with the configuration option (with the default set to 3-level). I realize that is only of marginal use, as you have the issue of getting OSDs to ship with a kernel configured this way, and getting ISVs to qualify their applications to run on this configuration. But don't you already have that issue with persuading them to ship with CONFIG_NR_CPUS=16384? Surely there are a whole boatload of tuneables and patches needed to get this sized system up and running? 4-level pagetables are just one piece of the puzzle. -Tony - To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.htmlReceived on Thu Nov 10 05:44:55 2005
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