Each method has its own roots. The struct bd_info originated in U-Boot, and struct bi_record was an attempt to unify across all platforms. Both are supported by many platforms.
114
To preserve space, we temporarily removed many machine types in Figure 16-4 prior to LITE5200.
115
We neglect the context switching time for interrupt processing because it is often negligible compared to interrupt off time.
116
Robert Love explains bottom-half processing in great detail in his book Linux Kernel Development. See Section 17.5.1, 'Suggestions for Additional Reading,' at the end of this chapter for the reference.
117
Interestingly, there is much debate on the correct spelling of preemptable! I defer to the survey done by Rick Lehrbaum on www.linuxdevices.com/articles/AT5136316996.html.
118
Also called HARDIRQs.
119
See Linux Kernel Development, referenced at the end of this chapter, to learn more about softirqs.
120
See www.rdrop.com/users/paulmck/RCU/ for an in-depth discussion of RCU.
121
We refer you again to Robert Love's book for an excellent discussion of the O(1) scheduler, and a delightful diatribe on algorithmic complexity, from which the notation O(1) derives.
