In-Reply-To: <20060130200026.GA5081@agluck-lia64.sc.intel.com> On Mon, 30 Jan 2006, Tony Luck wrote: > Might it be wise to see whether the 2% variation that I saw can be > repeated on some other architecture? Bjorn's initial post was just > questioning whether we need to spend this much time during boot to acquire > this data. Now we have *one* data point that on an ia64 with four cpus > with 9MB cache in a single domain that we can speed the calculation by > a factor of three with only a 2% loss of accuracy. Can someone else try > this patch and post the before/after values for migration_cost from dmesg? Before: messages.1:Jan 24 01:19:45 d2 kernel: [ 6.377117] migration_cost=9352 messages.1:Jan 27 21:07:55 d2 kernel: [ 6.384871] migration_cost=9329 messages.1:Jan 28 11:00:32 d2 kernel: [ 6.384215] migration_cost=9338 messages.1:Jan 28 12:55:03 d2 kernel: [ 6.389189] migration_cost=9364 After: messages:Jan 31 07:55:07 d2 kernel: [ 1.859359] migration_cost=9274 This was on a dual PII Xeon with 2MB L2 cache. About 3.5x as fast and only 1% change. Maybe the default could be to run the quick test with an option to run the more-accurate one? -- Chuck - 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 Wed Feb 01 11:53:24 2006
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