Re: System hang problem.

[Alan Cox <alan@lxorguk.ukuu.org.uk>]

Ar Maw, 2006-10-03 am 15:07 -0700, ysgrifennodd Manish Neema:
> RHEL3.0 U3 would generate an OOM kill "each and every time" it sensed
> system hang but due to other bugs, we had to move away from it. RedHat

And often when it didn't need too which for many users workloads is bad

> Changing overcommit to 2 (and ratio to any where from 1 to 99) would
> result in certain OS processes (automount daemon for e.g.) getting
> killed when all the allowed memory is committed. What is the point in

Killed and logging an OOM message ? That indicates a bug (well for ratio
<= about 50% anyway). Killed because there is no memory and a memory
allocation fails is expected.

> reserving some memory if a random root process would get killed leaving
> the system in a totally unknown state?

If you run out of memory and someone asks for more something has to
give. A properly configured system really shouldn't be running out of
memory anyway for most sane workloads.

It's like putting water in a bottle, at the point you have more water
than bottle something has to spill, if it doesn't the box hangs.

Alan

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/