Why call calibrate_delay() in smp.c: secondary_start_kernel()

Jonas Aaberg jonas.aberg at stericsson.com
Tue Jan 18 03:43:46 EST 2011


Hi,

calibrate_delay() calculates loops_per_jiffy. loops_per_jiffy is not per cpu.
Therefore I wonder why there is a calibrate_delay() call in smp.c: 
secondary_start_kernel()?

If you don't set lpj= it looks like it just takes longer time to boot
and bring a secondary cpu online.

u8500 seems to do fine without the calibrate_delay() call.

Best regards,
 Jonas Aaberg




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