Re: Some OpenWrt port related problems

[Ken Raeburn <raeburn@raeburn.org>]

On Jan 2, 2011, at 08:53, David Kuehling wrote:
> Well, if those pages are not modified, no memory is needed from the OS
> anyway (i.e. copy-on-write/lazy copy).  Just that linux VM manager seems
> to usually check whether it has enough pages just-in-case.
> 
> Similar problems seem to crop up with fork();exec() inside emacs.  So
> enabling overcommitting on the NanoNote may be a good thing in general.

Eh.. I've never been convinced that it's a good thing.  I like the fact that mmap/malloc can fail, and give you a chance to recover, rather than simply having a process blown out of the water when it turns out that a page isn't actually available after all.  But that's just me....

>  $ readelf -t /usr/bin/emacs
> 
>  There are no sections in this file.
> 
> :) 
> 
> Could it be that 'sstrip' (that's no typo, it's not vanilla 'strip')
> used for openwrt packages causes collateral damage here?  Emacs won't be
> the only package effected.

Okay, then you are doing something different...  I don't know how unexelf.c is going to handle a file with no section headers.  As best I recall, they're not critical for execution, but unexelf.c may be making additional assumptions based on how other systems tend to operate.  Ideally, I think it should be possible to just extent the loadable data sections, but that's not how unexelf.c operates.  If you can bypass 'sstrip' for a package, or just one executable in the package (emacsclient should be fine to strip, for example), that might fix the problem and allow you to have it dump during installation.

Ken