options DIAGNOSTIC

[Paul Goyette <paul%whooppee.com@localhost>]

With the recent discussion about DIAGNOSTIC perhaps having a 15% 
performance penalty, I took a quick look at some kernel config files.

It seems that we are not at all consistent about the comments on the 
"options DIAGNOSTIC" lines!  What I find most interesting in the 
following is 34 config files claim that the DIAGNOSTIC checks are 
expensive while 50 files claim that they are [Cc]heap!  (More than 150 
other files make no claim at all on the magnitude of cost.)

# grep -h DIAGNOSTIC src/sys/arch/*/conf/* | \
? tr '\t' ' ' | \
? sed -e 's/  */ /g' -e 's/^[# ]*//' | \
? sort | \
? uniq -c | \
? sort -r
  56 options DIAGNOSTIC # internally consistency checks
  53 options DIAGNOSTIC # extra kernel sanity checking
  42 options DIAGNOSTIC # cheap kernel consistency checks
  32 options DIAGNOSTIC # expensive kernel consistency checks
  20 options DIAGNOSTIC # internal consistency checks
  15 options DIAGNOSTIC # extra kernel debugging checks
  12 options DIAGNOSTIC
  10 options DIAGNOSTIC # Extra kernel sanity checks
   8 options DIAGNOSTIC # Cheap kernel consistency checks
   5 options DIAGNOSTIC, DEBUG
   3 no options DIAGNOSTIC
   3 depend on DIAGNOSTIC etc.
   2 options DIAGNOSTIC # expensive kernel consistency check
   1 options RAID_DIAGNOSTIC # Additional raidframe diagnostic info
   1 options DIAGNOSTIC,DEBUG,KMEMSTATS,PMAPDEBUG,TRAPDEBUG
   1 options DIAGNOSTIC # already in GENERIC
   1 options DIAGNOSTIC # Add additional error checking code
   1 depend on DEBUG and/or DIAGNOSTIC options
#

Would it make sense to have all kernel config files use a common 
description for the DIAGNOSTIC option?

With a similar examination of options DEBUG, we find somewhat less 
variation; but I still wonder if we should be consistend in how the 
option is described?

# grep -h '[^_A-Z]DEBUG[^_A-Z=.,:)}]' */conf/* | \
? tr '\t' ' ' | \
? sed -e 's/  */ /g' -e 's/^[# ]*//' | \
? sort | \
? uniq -c | \
? sort -r
  79 options DEBUG # expensive debugging checks/support
  46 options DEBUG # extra kernel debugging support
  16 options DEBUG # kernel debugging code
  10 options DEBUG # Enable misc. kernel debugging code
   3 options DEBUG # More expensive checks and printfs
   3 DEBUG options turned on:
   2 options DEBUG # Expensive debugging checks/support
   1 depend on DEBUG and/or DIAGNOSTIC options
#


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| Paul Goyette     | PGP Key fingerprint:     | E-mail addresses:       |
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| Kernel Developer |                          | pgoyette at netbsd.org  |
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