Re: [PATCH v5 6/7] x86/tlb: optimizing flush_tlb_mm
From: Alex Shi
Date: Tue May 15 2012 - 09:29:00 EST
On 05/15/2012 09:27 PM, Luming Yu wrote:
> On Tue, May 15, 2012 at 9:06 PM, Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> wrote:
>> On Tue, 2012-05-15 at 20:58 +0800, Luming Yu wrote:
>>> Both __native_flush_tlb() and __native_flush_tlb_single(...)
>>> introduced roughly 1 ns latency to tsc sampling executed in
> Fix typo, I just observed 1us with current tool, I would check if I
> can push the accuracy to nanoseconds level.
>>> stop_machine_context in two logical CPUs
>> But you have to weight that against the cost of re-population, and
> Right, it's hard to detect, but I will try if I can get measurement
> done in a simple test tool to help people measure
> this kind of stuff in few minutes.
>> that's the difficult bit, since we have no clue how many tlb entries are
>> in use by the current cr3.
>> It might be possible for intel to give us this information, I've asked
>> for something similar for cachelines.
> This is the official document
Please, such huge documents! and it also has no such info.
> Let me know if it can answer your question.
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