xbdelacour@yahoo.com writes:
> I'm no Unix expert, but this would seem to indicate that shmget is
> successfully allocating 400385024/1024/1024=381MB of shared memory. I don't
> know enough about how the postgres parent/child/shmem scheme works to know
> why this is working yet the children only register 12MB of shared memory
> under top.
On most of the systems I've worked on, top does not seem to count shmem
blocks that a process is attached to in the process' memory usage. So
that doesn't prove much one way or the other.
I am wondering if your version of 'top' fails to count swapped-out shmem
segments against swap space, or something like that. That'd be a tad
weird, but it seems very improbable that your machine is not swapping;
I just do not believe top's claim that no swapping is happening.
Anyway, the most direct experiment would be to reduce your -B request to
100MB or so and see how things change...
regards, tom lane