[Crash-utility] question on some command params

[Dave Anderson]

Jun Koi wrote:
> Great, it is clear to me now!
> 
> I have another question: what is the purpose of the "-L" option?
> 
> Thanks,
> Jun

It tries to lock all of the crash utility's mapped pages into
memory and prevents them from being paged out during the crash
session.  (man mlockall)

                 case 'L':
                         if (mlockall(MCL_CURRENT|MCL_FUTURE) == -1)
                                 perror("mlockall");
                         break;

It's fairly useless unless perhaps you are debugging a live
system and don't want any paging-out activity of the crash
session itself to interfere with whatever you might be looking
at on the live system.  Or you may just want better response
during live system analysis on a heavily-loaded system.
I don't recall what I was doing that led me to adding it.
It's a debug leftover that should not be used unless you
really have a need for it.

Dave