* Peter Zijlstra peterz@infradead.org wrote:
[...]
The reason Ingo took it out was that these measured numbers would slightly vary from boot to boot making it hard to compare performance numbers across boots.
There's something to be said for either case I suppose.
Yeah, so we could put the parameters back by measuring it in user-space via a nice utility in tools/, and by matching it to relevant hardware signatures (CPU type and cache sizes), plus doing some defaults for when we don't have any signature... possibly based on a fuzzy search to find the 'closest' system in the table of constants.
That would stabilize the boot-to-boot figures while still keeping most of the system specific-ness, in a maintainable fashion.
The downside is that we'd have to continuously maintain a table of all this info, with new entries added when new CPUs are introduced on the market. That's an upside too, btw.
Thanks,
Ingo