Re: ITP memlockd

[paddy@panici.net]

On Fri, Feb 09, 2007 at 08:57:19AM +1100, Russell Coker wrote:
> memlockd - daemon to lock files into RAM
> 
> When a system starts paging excessively it may be impossible for the sysadmin 
> to login for the purpose of killing the runaway processes (sometimes the 
> login program times out due to thrashing).  Memlockd allows important system 
> files (such as /bin/login, /bin/getty, and the admin shell) to be locked in 
> memory so that there will be no delay in accessing executable pages.  In my 
> tests this can decrease the time required for the administrator to login on a 
> thrashing system by a factor of more than 3.
> 
> GPL, I wrote it.

superb, I've wanted one of these for a long time :-)

Other scenarios might include having a working system if the binary
images are not acccessible for some other reason such as h/w failure ??

I had thought that the sticky bit had once been used like this? 
but I went away and read just now that it was a bit different.

I take it you handle package installs ?

How does it interact with the filesystem? I imagine that if I rm
/bin/bash then I can no longer simply execute it in the usual way,
even if the pages are still locked in memory (and do you unlock
the pages when the underlying file is removed ?)

Is there any guarantee that the various directories and inodes needed
(are they needed??) will be in memory ?

I have too many questions ...

Where can I get the code ?  :-)

Regards,
Paddy