Machine unresponsive with cache_lock: blocked on... message

Samuel J. Greear sjg at
Fri Mar 12 03:05:59 PST 2010

> 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.

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.

More information about the Bugs mailing list