semaphore and mutex in current Linux kernel (3.2.2)

From: Chen, Dennis (SRDC SW)
Date: Sun Apr 01 2012 - 05:57:24 EST


Documentation/mutex-design.txt:

"- 'struct mutex' is smaller on most architectures: E.g. on x86,
'struct semaphore' is 20 bytes, 'struct mutex' is 16 bytes.
A smaller structure size means less RAM footprint, and better
CPU-cache utilization."
================================================================
Now in my x86-64 32-bit Linux environment, 'struct semaphone' is 16 bytes,
'struct mutex' is 20 bytes. So seems the RAM footprint advantages are not there...

For the performance advantages followed, I don't have the ./test-mutex and maybe the
testing environment, so haven't the 1st hand data for this item...




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