Re: Can context switches be faster?

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John Richard Moser wrote:
That's a load more descriptive :D

0.890 uS, 0.556uS/cycle, that's barely 2 cycles you know.  (Pentium M)
PPC performs similarly, 1 cycle should be about 1uS.

No, you're a factor of 1000 off - these numbers show the context switch is around 1600-75000 cycles. And that doesn't really tell the whole story: if caches/TLB get flushed on context switch, then the newly switched-to task will bear the cost of having cold caches, which isn't visible in the raw context switch time.

But modern x86 processors have a very quick context switch time, and I don't think there's much room for improvement aside from micro-optimisations (though that might change if the architecture grows a way to avoid flushing the TLB on switch).

   J
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