Why BOOT_PRINTK_DELAY "may adversely affect SMP systems"?

From: snakky . zhang
Date: Thu Oct 20 2011 - 05:23:30 EST


Hi experts,

I noticed there is an kernel option called BOOT_PRINTK_DELAY and some
warning messages in the Kconfig file as below:

NOTE: Using this option may adversely affect SMP systems. I.e.,
processors other than the first one may not boot up. BOOT_PRINTK_DELAY
also may cause DETECT_SOFTLOCKUP to detect what it believes to be lockup
conditions.

As my understanding, this do nothing but just let the very CPU loop for
a while and shouldn't cause any affect on the boot process. So I can
hardly understand WHY it may cause "processors other than the first one
may not boot up"? If this issue can be avoid/fixed?

Thanks a lot!
Snakky

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