Re: cli/sti vs local_cmpxchg and local_add_return

[Andika Triwidada]

Older IA-64

processor  : 3
vendor     : GenuineIntel
arch       : IA-64
family     : 32
model      : 0
model name : Intel(r) Itanium(r) 2 Processor 1.6GHz with 18M L3 Cache
for 533MHz Platforms
revision   : 7
archrev    : 0
features   : branchlong, 16-byte atomic ops
cpu number : 0
cpu regs   : 4
cpu MHz    : 1594.911
itc MHz    : 399.226174
BogoMIPS   : 3186.68
siblings   : 2
physical id: 1
core id    : 1
thread id  : 0

test init
test results: time for baseline
number of loops: 20000
total time: 10003
-> baseline takes 0 cycles
test end
test results: time for locked cmpxchg
number of loops: 20000
total time: 60073
-> locked cmpxchg takes 3 cycles
test end
test results: time for non locked cmpxchg
number of loops: 20000
total time: 60014
-> non locked cmpxchg takes 3 cycles
test end
test results: time for locked add return
number of loops: 20000
total time: 150007
-> locked add return takes 7 cycles
test end
test results: time for non locked add return
number of loops: 20000
total time: 150009
-> non locked add return takes 7 cycles
test end
test results: time for enabling interrupts (STI)
number of loops: 20000
total time: 45003
-> enabling interrupts (STI) takes 2 cycles
test end
test results: time for disabling interrupts (CLI)
number of loops: 20000
total time: 59999
-> disabling interrupts (CLI) takes 2 cycles
test end
test results: time for disabling/enabling interrupts (STI/CLI)
number of loops: 20000
total time: 105001
-> enabling/disabling interrupts (STI/CLI) takes 5 cycles
test end
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