Re: la la la la ... swappiness

Christoph Lameter
2006-12-04T17:04:31Z

On Sun, 3 Dec 2006, Linus Torvalds wrote:

> Wouldn't it be much nicer to just lower the dirty-page limit?
>
> echo 1 > /proc/sys/vm/dirty_background_ratio
> echo 2 > /proc/sys/vm/dirty_ratio

Dirty ratio cannot be set to less than 5%. See
mm/page-writeback.c:get_dirty_limits().

> or something. Which we already discussed in another thread and almost
> already decided we should lower the values for big-mem machines..

We also have an issue with cpusets. Dirty page throttling does not work in
a cpuset if it is relatively small to the total memory on the system since
we calculate the percentage of the total memory and not a percentage of
the memory the process is allowed to use.