
An Overview of Kernel Lock Improvements [pdf] - mmastrac
http://events.linuxfoundation.org/sites/events/files/slides/linuxcon-2014-locking-final.pdf 
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xroche
Note: for those interested, MCS locks and qspinlocks are discussed in this
fine article:
[http://lwn.net/Articles/590243/](http://lwn.net/Articles/590243/)

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MoOmer
This is great; I'm still reading through, but, I had no idea that the
performance drop was that steep!

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jebblue
Do you mean the drop they later used to analyze cache line coherency when
adding cores? They improved this if I understood the latter results correctly.

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fmstephe
Can anyone explain the use of 'round-robin' to describe mulit-node scenarios
and 'fill-first' for single node scenarios. I initially assumed they were
describing thread schedulers, but that doesn't make clear sense in these
tests. Thanks in advance.

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readerrrr
This is the key: _each locker spins on local memory rather than the lock word_
at page 63.

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yxhuvud
It would be interesting to see the same benchmarks for more normal amounts of
cores. Most system does not have 240 cores, after all..

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readerrrr
The latest Intel hi-end desktop cpu has 8 cores. With hyper-threading; which
makes 16 threads.

I think in the next 10 years we will reach a number that is close.

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MaxBarraclough
If you count Xeon Phi, Intel are already up to 61.

[http://ark.intel.com/products/family/71840/Intel-Xeon-Phi-
Co...](http://ark.intel.com/products/family/71840/Intel-Xeon-Phi-Coprocessors)

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molixiaoge
great

