Re: Setting oom_adj on linux?

Magnus Hagander <magnus(at)hagander(dot)net> writes:
> I realize this is a very platform-specific thing, but should we
> consider setting the value of /proc/<pid>/oom_adj when running on
> linux? See:
> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=Documentation/filesystems/proc.txt;h=220cc6376ef80e0c9bcfec162d45552e729cdf5a;hb=45d28b097280a78893ce25a5d0db41e6a2717853

One interesting thing I read there is:

Swapped out tasks are killed first. Half of each child's memory size is
added to the parent's score if they do not share the same memory.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

This suggests that PG's shared memory ought not be counted in the
postmaster's OOM score, which would mean that the problem shouldn't be
quite as bad as we've believed. I wonder if that is a recent change?
Or maybe it's supposed to be that way and is not implemented correctly?

BTW, the given link shows only chapter 1, see

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob_plain;f=Documentation/filesystems/proc.txt;hb=45d28b097280a78893ce25a5d0db41e6a2717853

for the whole file.

regards, tom lane