Re: Machine unresponsive with cache_lock: blocked on... message

["Samuel J. Greear" <sjg@xxxxxxxxxxxx>]

> This particular machine has 2GB main memory.
>
> I've noticed 2.5 has a tendency to swap more than 2.4; it seems heavy disk
> activity (rsync) gets cached at the expense of running applications.
>

rsync behaves a bit differently than a run of tar or cpdup, it walks
the whole directory structure poking files and generates a list and
then starts acting on the list. I would guess this is enough to land
the associated pages in the VM active queue whereas cpdup would not,
taking a more direct approach.

http://gitweb.dragonflybsd.org/dragonfly.git/commit/0e8bd897b2ebcf1a575536f3bfdd88fe2377cc27

AFAICT the decision logic on whether to place a page on the inactive
or active queue is centered around the vfs.vm_cycle_point sysctl, you
could try raising it.