Improving the kernel/i386 timecounter performance (GSoC proposal)

[Peter Jeremy]

On 2009-Mar-29 08:35:45 +0800, David Xu <davidxu at freebsd.org> wrote:
>Julian Elischer wrote:
>> interestingly it is even feasible to have a per-thread page..
>> it requires that the scheduler change a page table entry tough.
>
>I will knock his door at midnight if he added such a heavy weight
>task in the scheduler, TLB shutdown is horrible, and big code size
>squeezing out data from CPU cache is not idea model.
>scheduler should be as simple as just a context switching routine.

If the TSC is not consistent between all cores (which is probably
the most common situation at present), then using the TSC implies
knowing which core you are executing on.  From a userland perspective,
the easiest way to do this is to have a page of data that varies
depending on which core you are executing on.

-- 
Peter Jeremy
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