Messages in this thread | | | From | Andi Kleen <> | Subject | Re: [patch] x86: unify/rewrite SMP TSC sync code | Date | Fri, 24 Nov 2006 18:13:13 +0100 |
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> make the TSC synchronization code more robust, and unify it between > x86_64 and i386. > > The biggest change is the removal of the 'fix up TSCs' code on x86_64 > and i386, in some rare cases it was /causing/ time-warps on SMP systems.
On x86-64 I don't think it can since it doesn't check anymore on sync Intel.
> The new code only checks for TSC asynchronity - and if it can prove a > time-warp (if it can observe the TSC going backwards when going from one > CPU to another within a critical section), then the TSC clock-source is > turned off.
The trouble is that people are using the RDTSC anyways even if the kernel doesn't. So some synchronization is probably a good idea.
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