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Messages in this thread Complete thread (EXPERIMENTAL) |
On Tue, 17 Dec 2002, Linus Torvalds wrote: How about this patch? Instead of making a per-cpu trampoline, write to
the msr during each context switch.
I wanted to avoid slowing down the context switch, but I didn't actually time how much the MSR write hurts you (it needs to be conditional, though, I think). this is the solution i took in the original vsyscall patches. The syscall entry cost is at least one factor more important than the context-switch cost. The MSR write was not all that slow when i measured it (it was on the range of 20 cycles), and it's definitely something the chip makers should keep fast. Ingo | ||||||||||
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