[Durham] Swap fills up then out of memory errors

[Oliver Burnett-Hall]

On 18 February 2012 10:29, Martin Ward <martin at gkc.org.uk> wrote:
>
> I don't think that a mixer plugin and a volume daemon (xfce4-mixer-plu
> and xfce4-volumed) should be taking nearly 400MB between them!

I'm not sure exactly how these figures reported by the oom-killer are
calculated, but shared memory is probably over-reported, so the total
memory used by the various XFCE4 processes is likely to be
considerably less than you'd get by adding up the individual entries.

> (I am assuming that the "total_vm" column is in KB: but you appear
> to have about 7GB of swap, while the "total_vm" column totals
> to only 3,378,926: so the column might be the number of 4K pages).

Good call.  I can't find any decent documentation on the format of the
oom-killer's output, but digging into the kernel sources gives this:
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=blob;f=mm/oom_kill.c;h=2958fd8e7c9abcfcf6cc7b38e2dac34133905b22;hb=HEAD#l377.
The memory information dumped comes from a mm_struct object, and that
does record things in pages.

Multiplying everything by 4KB also makes the memory reported in the
dumped as used by x-www-browser much closer to the totals reported in
the last line when that process is killed.

Dougie -- what browser are you using?

- olly