Hi, currently the NanoNote comes with a setting of /proc/sys/vm/overcommit_memory = 0. This makes Linux' memory manager overly fussy with memory allocations, memory mappings and fork().
The result is that large applications like Octave do not start due to missing memory, or sometimes a large application like Emacs is unable to execute a child process via fork() and exec() since the memory manager asseses that memory would not suffice to perform fork() on a huge process. In reality, memory mostly *does* suffice, though. It's just that there are more pages assigned to processes, than there is available RAM. Especially with large executables this is not a problem, since executables are mapped read-only from disk files to memory. If memory runs low, these read-only pages can just be dropped, and reloaded from disk whenever they are needed again. Setting /proc/sys/vm/overcommit_memory = 1 makes Linux memory manager more generous and allows processes to occupy more pages than there is RAM. The downside is, that applications then sometimes don't fail on calling malloc(), but instead segfault when they try to access pages that cannot be allocated to available RAM. In reality I've seen that the Linux OOM killer comes along and kills applications that it deems to memory hungry. I saw that behaviour with overcommit_memory set to 0 as well to 1, so I guess generally setting it to 1 won't make things much worse than they are already. So are you ok with such a change? The right place to change that setting would be from /etc/sysctl.conf. Should I add a sysctl.conf to data/qi_lb60/files/etc/ ? Would be nice to add it in a place that effects config.minimal as well as config.full_system. I want my config.minimal images to be able to run Octave out-of-the-box. BTW Octave consists of about 38MB of read-only library code that needs to be mapped. Of course depending on what you do, you won't actually use most of that code. cheers, David PS: some more info is available here: http://www.mjmwired.net/kernel/Documentation/sysctl/vm.txt -- GnuPG public key: http://user.cs.tu-berlin.de/~dvdkhlng/dk.gpg Fingerprint: B17A DC95 D293 657B 4205 D016 7DEF 5323 C174 7D40
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