On Mon, Aug 08, 2011 at 10:31:49PM +0800, Peter Zijlstra wrote:

On Mon, 2011-08-08 at 22:11 +0800, Wu Fengguang wrote:

quoted

It's actually dead code because (origin < limit) should never happen.
I feel so good being able to drop 5 more lines of code :) 

OK, but that leaves me trying to figure out what origin is, and why its
4 * thresh.

origin is where the control line crosses the X axis (in both the
global/bdi setpoint cases).

"4 * thresh" is merely something larger than max(dirty, thresh)
that yields reasonably gentle slope. The more slope, the larger
"gravity" to bring the dirty pages back to the setpoint.

I'm having a horrible time understanding this stuff.

Sorry for that. Do you have more questions?

Thanks,
Fengguang

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>