• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 334
  • Last Modified:

kernel config - debug considerations

I am customizing a kernel starting with a RedHat premade config file. I noticed kernel debug is selected as the default; however, I will be intending to use this kernel for "production" servers. What are the caveats/considerations, etc regarding this option. On one hand I want good info in the event of a problem, but not at te expense of a considerable (say 10-15%) speed hit.
0
medent
Asked:
medent
  • 2
  • 2
1 Solution
 
ahoffmannCommented:
which one do you mean?
  CONFIG_DEBUG_ERRORS
 
0
 
medentAuthor Commented:
Here is the kernel section (default redhat config)...

CONFIG_DEBUG_KERNEL=y
# CONFIG_DEBUG_HIGHMEM is not set
# CONFIG_DEBUG_SLAB is not set
# CONFIG_DEBUG_IOVIRT is not set
CONFIG_MAGIC_SYSRQ=y
# CONFIG_DEBUG_SPINLOCK is not set
CONFIG_DEBUG_BUGVERBOSE=y
# CONFIG_HIGHMEM_EMULATION is not set
CONFIG_KALLSYMS=y

0
 
ahoffmannCommented:
AFAIK you may savely unset CONFIG_DEBUG_KERNEL and also CONFIG_MAGIC_SYSRQ.
Don't know about CONFIG_DEBUG_BUGVERBOSE, probaly RH special. Probably it's useless anyway if the other 2 are unset.
0
 
medentAuthor Commented:
I realize these are optional and I can safely unset them, I am looking for details to support having this on or off, what is the performance hit with debugging on, or what happens if you have a (driver,etc) problem w/o debugging on..?
0
 
pheurCommented:
CONFIG_DEBUG_BUGVERBOSE doesn't affect performance. Just takes about 100K of memory, an affordable thing these days. It sends via printk information that aids identifying a bug, after the boggy condition occurred.
CONFIG_MAGIC_SYSRQ is even recommended in production.
About support, I can't tell you anything, it's you the one that has to look in the support contract if you have something like that. Most Linux people live very happy without OS support contracts because it's either not necessary, or the skills needed to solve various problems are available in-house. I've seen LARGE companies that use Linux and only buy support for hardware.

--
Radu-Adrian Feurdean
Brainbench Linux MVP
0

Featured Post

Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

  • 2
  • 2
Tackle projects and never again get stuck behind a technical roadblock.
Join Now