Re: On the issue of low memory situations

From: Linda Walsh (
Date: Fri Mar 17 2000 - 19:24:49 EST

Nicholas Vinen wrote:
> I can't pretend to be an expert but I'd like to throw a comment or two into
> the overcommitment and out of memory issues being discussed.
> First, with overcommitment, a process could find itself going to access
> memory to write to it and there's no space to commit to its allocation any
> more. In this case, I can think of a few things that could happen. The write
> could fault. The write could block until that memory became available. The
> allocation of the page could even block if memory is low, rather than out. I
> think being able to select this behaviour is going to be important, in
> combination perhaps with a userland daemon.
> For example, if root could allocate one of these three behaviours to each
> process,

        I haven't read through this whole thread, so this may have been
suggested, but why not have a new signal "SIGNMEM". Can't be caught but
can be ignored. Default is to take the signal and terminate the program
that faulted. If ignored, put process to sleep until the memory request
can be satisfied. Then something like 'X' or apache could ignore, while
'gcc' would just die.


Linda A Walsh                    | Trust Technology, Core Linux, SGI                      | Voice: (650) 933-5338

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