Improvement request for Handbook section 8.4: adaptive_giant

Jan Gundtofte-Bruun jan at
Mon Nov 1 14:07:06 UTC 2004

I was just browsing the "compile your own kernel" section in the 
handbook, and I must say that it is excellently written. I have never 
compiled a kernel, and this section is kept in a language that is 
friendly and understandable to a mortal like me. Considering the 
subject, that is quite a feat.

However, there is one line, in section 8.4, that sticks out:

   options          ADAPTIVE_GIANT    # Giant mutex is adaptive.

This option causes Giant to be included in the set of mutexes adaptively spun on.

The wording of this line is in contrast to the rest of the document, the 
description is simply not adding any value. I have no idea if it would 
be dangerous to comment this line out (to optimize).
I don't think I need to know why mutexes spin adaptively, but please 
consider spending 5 words to exlain what a Giant is used for, so that I 
can decide if I need this. At least, a safe default could be something 
like "If you don't know what a Giant is, you [should leave this in]/[can 
safely comment this out]."


:o) Jan Gundtofte-Bruun

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