Re: question on some command params

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Jun Koi wrote:
Hi,

I found below cmdline params having no documentation anywhere, so
could somebody explain their meaning?

- memory_module
- no_modules
- no_ikconfig
- no_namelist_gzip
- no_kmem_cache
- kmem_cache_delay
- readnow
- buildinfo
- zero_excluded


Many thanks,
J

They're all essentially debug flags for use on kernels/dumpfiles
that for some reason or other would not initialize properly.

memory_module: if /dev/mem or /dev/crash do not suffice you could
  force-feed one or the other for live system analysys.

no_modules: if the module initialization code cause crash to
  during initialization, skip it with --no_modules.

no_ikconfig: if the reading of the in-kernel config data causes
  an initialization-time failure, skip it with --no_ikconfig

no_namelist_gzip: completely obsolete

no_kmem_cache: if the kmem slab cache initialization causes an
  initialization-time failure, skip it with --no_kmem_cache

kmem_cache_delay: if the kmem slab cache initialization causes an
  initialization-time failure, it can alternatively be delayed
  until the first command that accesses the kmem_cache is run

readnow: useless now, but there was a very short period of time
  where gcc was creating debuginfo vmlinux files that required
  --readnow in order to gather all of the debug data at initialization
  time.

buildinfo: dumps information about who/where/when/gcc w/respect to
  the crash utility itself.

zero_excluded: if a page was excluded by diskdump or makedumpfile,
  it normally returns a failure if the page is accessed.  If you
  want it to just return a page of zeroes, use --zero_excluded.

In any case, if you find that you need to use any of the flags above,
then it's indicative of (1) a crash utility bug, or (2) a corrupted vmcore.
In either situation, it's best to find and fix the underlying problem
instead of working around it.  Using the flags above is only a stop-gap
measure, and should not be "depended upon".

Dave

--
Crash-utility mailing list
Crash-utility@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/crash-utility

[Index of Archives]     [Fedora Development]     [Fedora Desktop]     [Fedora SELinux]     [Yosemite News]     [KDE Users]     [Fedora Tools]

 

Powered by Linux