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Re: Dynamically allocated locks

On Mar 25, 2008, at 1:04 PM, wrote:
In message <>,
Jason Thorpe writes:

On Mar 24, 2008, at 10:10 AM, Matt Thomas wrote:

Yes.  One / cacheline size is a dramatic waste of space.  Some
systems have
128 bytes per cacheline.  On systems with small caches or UP systems
extremely expensive.

Two independent locks in a single cache line is guaranteed to crease a
false-sharing situation.  It is best avoided, even if cache pressure
is the trade-off.

Even on a UP system?  In the kernel? Surely not.

Obviously on a UP system, it doesn't matter, and Andy already suggested that he would change the code to account for that.

-- thorpej

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