Re: [Crash-utility] question on some command params

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".